| <!doctype html><html lang=en-US dir=ltr class="docs-wrapper plugin-docs plugin-id-default docs-version-0.17 docs-doc-page docs-doc-id-guide/java/schema_evolution" data-has-hydrated=false><head><meta charset=UTF-8><meta name=generator content="Docusaurus v3.10.1"><title data-rh=true>Schema Evolution | Apache Fory™</title><meta data-rh=true name=viewport content="width=device-width, initial-scale=1.0"/><meta data-rh=true property=og:url content=https://fory.apache.org/docs/0.17/guide/java/schema_evolution /><meta data-rh=true property=og:locale content=en_US /><meta data-rh=true property=og:locale:alternate content=zh_CN /><meta data-rh=true name=docusaurus_locale content=en-US /><meta data-rh=true name=docsearch:language content=en-US /><meta data-rh=true http-equiv=Content-Security-Policy content="frame-src 'self' https://ghbtns.com/;"/><meta data-rh=true property=og:image content=https://fory.apache.org/img/logo.png /><meta data-rh=true property=og:image:width content=1500 /><meta data-rh=true property=og:image:height content=1500 /><meta data-rh=true name=twitter:card content=summary_large_image /><meta data-rh=true name=twitter:image content=https://fory.apache.org/img/logo.png /><meta data-rh=true name=docusaurus_version content=0.17 /><meta data-rh=true name=docusaurus_tag content=docs-default-0.17 /><meta data-rh=true name=docsearch:version content=0.17 /><meta data-rh=true name=docsearch:docusaurus_tag content=docs-default-0.17 /><meta data-rh=true property=og:title content="Schema Evolution | Apache Fory™"/><meta data-rh=true name=description content="This page covers schema evolution, meta sharing, and handling non-existent/unknown classes."/><meta data-rh=true property=og:description content="This page covers schema evolution, meta sharing, and handling non-existent/unknown classes."/><link data-rh=true rel=icon href=/img/favicon.ico /><link data-rh=true rel=canonical href=https://fory.apache.org/docs/0.17/guide/java/schema_evolution /><link data-rh=true rel=alternate href=https://fory.apache.org/docs/0.17/guide/java/schema_evolution hreflang=en-US /><link data-rh=true rel=alternate href=https://fory.apache.org/zh-CN/docs/0.17/guide/java/schema_evolution hreflang=zh-CN /><link data-rh=true rel=alternate href=https://fory.apache.org/docs/0.17/guide/java/schema_evolution hreflang=x-default /><script data-rh=true type=application/ld+json>{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","item":"https://fory.apache.org/docs/0.17/guide/java/","name":"Java","position":1},{"@type":"ListItem","item":"https://fory.apache.org/docs/0.17/guide/java/schema_evolution","name":"Schema Evolution","position":2}]}</script><link rel=alternate type=application/rss+xml href=/blog/rss.xml title="Apache Fory™ RSS Feed"><link rel=alternate type=application/atom+xml href=/blog/atom.xml title="Apache Fory™ Atom Feed"><script type=text/javascript>"fury.apache.org"===window.location.host&&(window.location.href="https://fory.apache.org"),function(){for(var o=window.location.pathname,a=["guide","introduction","start"],n=0;n<a.length;n++){var t=a[n],i=RegExp("^((?:/[a-z]{2}-[A-Z]{2})?/docs(?:/(?:next|[0-9]+.[0-9]+))?)/docs/"+t+"(/.*)?$"),c=o.match(i);if(c){var r=c[1]+"/"+t+(c[2]||"");window.location.replace(r+window.location.search+window.location.hash);return}}}()</script><link rel=stylesheet href=/assets/css/styles.3a1edaa1.css /><script src=/assets/js/runtime~main.605b11b1.js defer></script><script src=/assets/js/main.283fea4b.js defer></script></head><body><svg style="display: none;"><defs> |
| <symbol id=theme-svg-external-link viewBox="0 0 24 24"><path fill=currentColor d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"/></symbol> |
| </defs></svg> |
| <script>!function(){var t=function(){try{return new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}}()||function(){try{return window.localStorage.getItem("theme")}catch(t){}}();document.documentElement.setAttribute("data-theme",t||"light"),document.documentElement.setAttribute("data-theme-choice",t||"light")}(),function(){try{for(var[t,e]of new URLSearchParams(window.location.search).entries())if(t.startsWith("docusaurus-data-")){var a=t.replace("docusaurus-data-","data-");document.documentElement.setAttribute(a,e)}}catch(t){}}()</script><div id=__docusaurus><div role=region aria-label="Skip to main content"><a class=skipToContent_fXgn href=#__docusaurus_skipToContent_fallback>Skip to main content</a></div><nav aria-label=Main class="theme-layout-navbar navbar navbar--fixed-top"><div class=navbar__inner><div class="theme-layout-navbar-left navbar__items"><button aria-label="Toggle navigation bar" aria-expanded=false class="navbar__toggle clean-btn" type=button><svg width=30 height=30 viewBox="0 0 30 30" aria-hidden=true><path stroke=currentColor stroke-linecap=round stroke-miterlimit=10 stroke-width=2 d="M4 7h22M4 15h22M4 23h22"/></svg></button><a class=navbar__brand href=/><div class=navbar__logo><img src=/img/fory-logo-light.png alt="Apache Fory™ Logo" class="themedComponent_mlkZ themedComponent--light_NVdE"/><img src=/img/fory-logo-dark.png alt="Apache Fory™ Logo" class="themedComponent_mlkZ themedComponent--dark_xIcU"/></div><b class="navbar__title text--truncate"></b></a><a aria-current=page class="navbar__item navbar__link navbar__link--active" href=/docs/0.17/introduction/overview>Docs</a><a class="navbar__item navbar__link" href=/docs/0.17/specification/xlang_serialization_spec>Specification</a><a class="navbar__item navbar__link" href=/docs/0.17/community/>Community</a><a class="navbar__item navbar__link" href=/user>Users</a><a class="navbar__item navbar__link" href=/download>Download</a><a class="navbar__item navbar__link" href=/blog>Blog</a></div><div class="theme-layout-navbar-right navbar__items navbar__items--right"><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href=# aria-haspopup=true aria-expanded=false role=button class=navbar__link>ASF</a><ul class=dropdown__menu><li><a href=https://www.apache.org/ target=_blank rel="noopener noreferrer" class=dropdown__link>Foundation</a><li><a href=https://www.apache.org/licenses/ target=_blank rel="noopener noreferrer" class=dropdown__link>License</a><li><a href=https://www.apache.org/events/current-event.html target=_blank rel="noopener noreferrer" class=dropdown__link>Events</a><li><a href=https://privacy.apache.org/policies/privacy-policy-public.html target=_blank rel="noopener noreferrer" class=dropdown__link>Privacy</a><li><a href=https://www.apache.org/security/ target=_blank rel="noopener noreferrer" class=dropdown__link>Security</a><li><a href=https://www.apache.org/foundation/sponsorship.html target=_blank rel="noopener noreferrer" class=dropdown__link>Sponsorship</a><li><a href=https://www.apache.org/foundation/thanks.html target=_blank rel="noopener noreferrer" class=dropdown__link>Thanks</a><li><a href=https://www.apache.org/foundation/policies/conduct.html target=_blank rel="noopener noreferrer" class=dropdown__link>Code of Conduct</a></ul></div><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a class=navbar__link aria-haspopup=true aria-expanded=false role=button href=/docs/0.17/guide/java/schema_evolution>0.17</a><ul class=dropdown__menu><li><a class=dropdown__link href=/docs/next/guide/java/schema_evolution>dev</a><li><a class=dropdown__link href=/docs/guide/java/schema_evolution>1.3.0</a><li><a class=dropdown__link href=/docs/1.2.0/guide/java/schema_evolution>1.2.0</a><li><a class=dropdown__link href=/docs/1.1.0/guide/java/schema_evolution>1.1.0</a><li><a class=dropdown__link href=/docs/1.0.0/guide/java/schema_evolution>1.0.0</a><li><a aria-current=page class="dropdown__link dropdown__link--active" href=/docs/0.17/guide/java/schema_evolution>0.17</a><li><a class=dropdown__link href=/docs/0.16/guide/java/schema_evolution>0.16</a><li><a class=dropdown__link href=/docs/0.15/guide/java/schema_evolution>0.15</a><li><a class=dropdown__link href=/docs/0.14/guide/java/schema_evolution>0.14</a><li><a class=dropdown__link href=/docs/0.13/introduction/overview>0.13</a><li><a class=dropdown__link href=/docs/0.12/introduction/overview>0.12</a><li><a class=dropdown__link href=/docs/0.11/introduction/overview>0.11</a><li><a class=dropdown__link href=/docs/0.10/introduction/overview>0.10</a></ul></div><a href=https://github.com/apache/fory target=_blank rel="noopener noreferrer" class="navbar__item navbar__link header-github-link" aria-label="GitHub repository"></a><div class="navbar__item dropdown dropdown--hoverable dropdown--right"><a href=# aria-haspopup=true aria-expanded=false role=button class=navbar__link><svg viewBox="0 0 24 24" width=20 height=20 aria-hidden=true class=iconLanguage_nlXk><path fill=currentColor d="M12.87 15.07l-2.54-2.51.03-.03c1.74-1.94 2.98-4.17 3.71-6.53H17V4h-7V2H8v2H1v1.99h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04zM18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12zm-2.62 7l1.62-4.33L19.12 17h-3.24z"/></svg>English</a><ul class=dropdown__menu><li><a href=/docs/0.17/guide/java/schema_evolution target=_self rel="noopener noreferrer" class="dropdown__link dropdown__link--active" lang=en-US>English</a><li><a href=/zh-CN/docs/0.17/guide/java/schema_evolution target=_self rel="noopener noreferrer" class=dropdown__link lang=zh-CN>简体中文</a></ul></div><div class="toggle_vylO colorModeToggle_DEke"><button class="clean-btn toggleButton_gllP toggleButtonDisabled_aARS" type=button disabled title="system mode" aria-label="Switch between dark and light mode (currently system mode)"><svg viewBox="0 0 24 24" width=24 height=24 aria-hidden=true class="toggleIcon_g3eP lightToggleIcon_pyhR"><path fill=currentColor d="M12,9c1.65,0,3,1.35,3,3s-1.35,3-3,3s-3-1.35-3-3S10.35,9,12,9 M12,7c-2.76,0-5,2.24-5,5s2.24,5,5,5s5-2.24,5-5 S14.76,7,12,7L12,7z M2,13l2,0c0.55,0,1-0.45,1-1s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S1.45,13,2,13z M20,13l2,0c0.55,0,1-0.45,1-1 s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S19.45,13,20,13z M11,2v2c0,0.55,0.45,1,1,1s1-0.45,1-1V2c0-0.55-0.45-1-1-1S11,1.45,11,2z M11,20v2c0,0.55,0.45,1,1,1s1-0.45,1-1v-2c0-0.55-0.45-1-1-1C11.45,19,11,19.45,11,20z M5.99,4.58c-0.39-0.39-1.03-0.39-1.41,0 c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0s0.39-1.03,0-1.41L5.99,4.58z M18.36,16.95 c-0.39-0.39-1.03-0.39-1.41,0c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0c0.39-0.39,0.39-1.03,0-1.41 L18.36,16.95z M19.42,5.99c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06c-0.39,0.39-0.39,1.03,0,1.41 s1.03,0.39,1.41,0L19.42,5.99z M7.05,18.36c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06 c-0.39,0.39-0.39,1.03,0,1.41s1.03,0.39,1.41,0L7.05,18.36z"/></svg><svg viewBox="0 0 24 24" width=24 height=24 aria-hidden=true class="toggleIcon_g3eP darkToggleIcon_wfgR"><path fill=currentColor d="M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27C17.45,17.19,14.93,19,12,19 c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z M12,3c-4.97,0-9,4.03-9,9s4.03,9,9,9s9-4.03,9-9c0-0.46-0.04-0.92-0.1-1.36 c-0.98,1.37-2.58,2.26-4.4,2.26c-2.98,0-5.4-2.42-5.4-5.4c0-1.81,0.89-3.42,2.26-4.4C12.92,3.04,12.46,3,12,3L12,3z"/></svg><svg viewBox="0 0 24 24" width=24 height=24 aria-hidden=true class="toggleIcon_g3eP systemToggleIcon_QzmC"><path fill=currentColor d="m12 21c4.971 0 9-4.029 9-9s-4.029-9-9-9-9 4.029-9 9 4.029 9 9 9zm4.95-13.95c1.313 1.313 2.05 3.093 2.05 4.95s-0.738 3.637-2.05 4.95c-1.313 1.313-3.093 2.05-4.95 2.05v-14c1.857 0 3.637 0.737 4.95 2.05z"/></svg></button></div><div class=navbarSearchContainer_Bca1><div class=navbar__search><span aria-label="expand searchbar" role=button class=search-icon tabindex=0></span><input id=search_input_react type=search placeholder=Loading... aria-label=Search class="navbar__search-input search-bar" disabled/></div></div></div></div><div role=presentation class=navbar-sidebar__backdrop></div></nav><div id=__docusaurus_skipToContent_fallback class="theme-layout-main main-wrapper mainWrapper_z2l0"><div class=docsWrapper_hBAB><button aria-label="Scroll back to top" class="clean-btn theme-back-to-top-button backToTopButton_sjWU" type=button></button><div class=docRoot_UBD9><aside class="theme-doc-sidebar-container docSidebarContainer_YfHR"><div class=sidebarViewport_aRkj><div class=sidebar_njMd><nav aria-label="Docs sidebar" class="menu thin-scrollbar menu_SIkG"><ul class="theme-doc-sidebar-menu menu__list"><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" href=/docs/0.17/introduction/overview><span title=Introduction class=categoryLinkLabel_W154>Introduction</span></a><button aria-label="Collapse sidebar category 'Introduction'" aria-expanded=true type=button class="clean-btn menu__caret"></button></div><ul class=menu__list><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/introduction/overview><span title=Overview class=linkLabel_WmDU>Overview</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/introduction/features><span title=Features class=linkLabel_WmDU>Features</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/introduction/benchmark><span title=Benchmark class=linkLabel_WmDU>Benchmark</span></a></ul><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist menu__link--sublist-caret" role=button aria-expanded=true href=/docs/0.17/start/install><span title=Start class=categoryLinkLabel_W154>Start</span></a></div><ul class=menu__list><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/start/install><span title=Install class=linkLabel_WmDU>Install</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-2 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/start/usage><span title=Usage class=linkLabel_WmDU>Usage</span></a></ul><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist menu__link--sublist-caret" role=button aria-expanded=false href=/docs/0.17/compiler/><span title="Schema IDL & Compiler" class=categoryLinkLabel_W154>Schema IDL & Compiler</span></a></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-1 menu__list-item"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist menu__link--sublist-caret menu__link--active" role=button aria-expanded=true href=/docs/0.17/guide/java/><span title=Guide class=categoryLinkLabel_W154>Guide</span></a></div><ul class=menu__list><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist menu__link--active" tabindex=0 href=/docs/0.17/guide/java/><span title=Java class=categoryLinkLabel_W154>Java</span></a><button aria-label="Collapse sidebar category 'Java'" aria-expanded=true type=button class="clean-btn menu__caret"></button></div><ul class=menu__list><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/basic_serialization><span title="Basic Serialization" class=linkLabel_WmDU>Basic Serialization</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/configuration><span title=Configuration class=linkLabel_WmDU>Configuration</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/type_registration><span title="Type Registration & Security" class=linkLabel_WmDU>Type Registration & Security</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/custom_serializers><span title="Custom Serializers" class=linkLabel_WmDU>Custom Serializers</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/field_configuration><span title="Field Configuration" class=linkLabel_WmDU>Field Configuration</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/enum_configuration><span title="Enum Configuration" class=linkLabel_WmDU>Enum Configuration</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/compression><span title=Compression class=linkLabel_WmDU>Compression</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/java_virtual_threads><span title="Virtual Threads" class=linkLabel_WmDU>Virtual Threads</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class="menu__link menu__link--active" aria-current=page tabindex=0 href=/docs/0.17/guide/java/schema_evolution><span title="Schema Evolution" class=linkLabel_WmDU>Schema Evolution</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/advanced_features><span title="Advanced Features" class=linkLabel_WmDU>Advanced Features</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/cross_language><span title="Cross-Language Serialization" class=linkLabel_WmDU>Cross-Language Serialization</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/row_format><span title="Row Format" class=linkLabel_WmDU>Row Format</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/graalvm_support><span title="GraalVM Support" class=linkLabel_WmDU>GraalVM Support</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/migration><span title="Migration Guide" class=linkLabel_WmDU>Migration Guide</span></a><li class="theme-doc-sidebar-item-link theme-doc-sidebar-item-link-level-3 menu__list-item"><a class=menu__link tabindex=0 href=/docs/0.17/guide/java/troubleshooting><span title=Troubleshooting class=linkLabel_WmDU>Troubleshooting</span></a></ul><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/python/><span title=Python class=categoryLinkLabel_W154>Python</span></a><button aria-label="Expand sidebar category 'Python'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/rust/><span title=Rust class=categoryLinkLabel_W154>Rust</span></a><button aria-label="Expand sidebar category 'Rust'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/cpp/><span title=C++ class=categoryLinkLabel_W154>C++</span></a><button aria-label="Expand sidebar category 'C++'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/go/><span title=Go class=categoryLinkLabel_W154>Go</span></a><button aria-label="Expand sidebar category 'Go'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/javascript/><span title=JavaScript class=categoryLinkLabel_W154>JavaScript</span></a><button aria-label="Expand sidebar category 'JavaScript'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/csharp/><span title=C# class=categoryLinkLabel_W154>C#</span></a><button aria-label="Expand sidebar category 'C#'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/swift/><span title=Swift class=categoryLinkLabel_W154>Swift</span></a><button aria-label="Expand sidebar category 'Swift'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/dart/><span title=Dart class=categoryLinkLabel_W154>Dart</span></a><button aria-label="Expand sidebar category 'Dart'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/scala/><span title=Scala class=categoryLinkLabel_W154>Scala</span></a><button aria-label="Expand sidebar category 'Scala'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/kotlin/><span title=Kotlin class=categoryLinkLabel_W154>Kotlin</span></a><button aria-label="Expand sidebar category 'Kotlin'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div><li class="theme-doc-sidebar-item-category theme-doc-sidebar-item-category-level-2 menu__list-item menu__list-item--collapsed"><div class=menu__list-item-collapsible><a class="categoryLink_byQd menu__link menu__link--sublist" tabindex=0 href=/docs/0.17/guide/xlang/><span title="Cross Language" class=categoryLinkLabel_W154>Cross Language</span></a><button aria-label="Expand sidebar category 'Cross Language'" aria-expanded=false type=button class="clean-btn menu__caret"></button></div></ul></ul></nav></div></div></aside><main class=docMainContainer_TBSr><div class="container padding-top--md padding-bottom--lg"><div class=row><div class="col docItemCol_VOVn"><div class="theme-doc-version-banner alert alert--warning margin-bottom--md" role=alert><div>This is documentation for <!-- -->Apache Fory™<!-- --> <b>0.17</b>, which is no longer actively maintained.</div><div class=margin-top--md>For up-to-date documentation, see the <b><a href=/docs/guide/java/schema_evolution>latest version</a></b> (<!-- -->1.3.0<!-- -->).</div></div><div class=docItemContainer_Djhp><article><nav class="theme-doc-breadcrumbs breadcrumbsContainer_Z_bl" aria-label=Breadcrumbs><ul class=breadcrumbs><li class=breadcrumbs__item><a aria-label="Home page" class=breadcrumbs__link href=/><svg viewBox="0 0 24 24" class=breadcrumbHomeIcon_YNFT><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill=currentColor /></svg></a><li class=breadcrumbs__item><span class=breadcrumbs__link>Guide</span><li class=breadcrumbs__item><a class=breadcrumbs__link href=/docs/0.17/guide/java/><span>Java</span></a><li class="breadcrumbs__item breadcrumbs__item--active"><span class=breadcrumbs__link>Schema Evolution</span></ul></nav><span class="theme-doc-version-badge badge badge--secondary">Version: 0.17</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type=button class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>Schema Evolution</h1></header><p>This page covers schema evolution, meta sharing, and handling non-existent/unknown classes.</p> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=handling-class-schema-evolution>Handling Class Schema Evolution<a href=#handling-class-schema-evolution class=hash-link aria-label="Direct link to Handling Class Schema Evolution" title="Direct link to Handling Class Schema Evolution" translate=no></a></h2> |
| <p>In many systems, the schema of a class used for serialization may change over time. For instance, fields within a class may be added or removed. When serialization and deserialization processes use different versions of jars, the schema of the class being deserialized may differ from the one used during serialization.</p> |
| <h3 class="anchor anchorTargetStickyNavbar_Vzrq" id=default-mode-schema_consistent>Default Mode: SCHEMA_CONSISTENT<a href=#default-mode-schema_consistent class=hash-link aria-label="Direct link to Default Mode: SCHEMA_CONSISTENT" title="Direct link to Default Mode: SCHEMA_CONSISTENT" translate=no></a></h3> |
| <p>By default, Fory serializes objects using the <code>CompatibleMode.SCHEMA_CONSISTENT</code> mode. This mode assumes that the deserialization process uses the same class schema as the serialization process, minimizing payload overhead. However, if there is a schema inconsistency, deserialization will fail.</p> |
| <h3 class="anchor anchorTargetStickyNavbar_Vzrq" id=compatible-mode>Compatible Mode<a href=#compatible-mode class=hash-link aria-label="Direct link to Compatible Mode" title="Direct link to Compatible Mode" translate=no></a></h3> |
| <p>If the schema is expected to change, to make deserialization succeed (i.e., schema forward/backward compatibility), users must configure Fory to use <code>CompatibleMode.COMPATIBLE</code>. This can be done using the <code>ForyBuilder#withCompatibleMode(CompatibleMode.COMPATIBLE)</code> method.</p> |
| <p>In this compatible mode, deserialization can handle schema changes such as missing or extra fields, allowing it to succeed even when the serialization and deserialization processes have different class schemas.</p> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token class-name">Fory</span><span class="token plain"> fory </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token class-name">Fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>builder</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>withCompatibleMode</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">CompatibleMode</span><span class="token punctuation" style=color:#393A34>.</span><span class="token constant" style=color:#36acaa>COMPATIBLE</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>build</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token keyword" style=color:#00009f>byte</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> bytes </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">object</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token class-name">System</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">out</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>println</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">bytes</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><br/></div></code></pre></div></div> |
| <p>This compatible mode involves serializing class metadata into the serialized output. Despite Fory's use of sophisticated compression techniques to minimize overhead, there is still some additional space cost associated with class metadata.</p> |
| <h3 class="anchor anchorTargetStickyNavbar_Vzrq" id=disable-evolution-for-stable-classes>Disable Evolution for Stable Classes<a href=#disable-evolution-for-stable-classes class=hash-link aria-label="Direct link to Disable Evolution for Stable Classes" title="Direct link to Disable Evolution for Stable Classes" translate=no></a></h3> |
| <p>If a class schema is stable and will not change, you can opt out of schema evolution on a per-class basis to avoid compatible metadata overhead. Annotate the class with <code>@ForyObject(evolving = false)</code> to force <code>STRUCT/NAMED_STRUCT</code> type IDs even when Compatible mode is enabled.</p> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token keyword" style=color:#00009f>import</span><span class="token plain"> </span><span class="token import namespace" style=opacity:0.7>org</span><span class="token import namespace punctuation" style=opacity:0.7;color:#393A34>.</span><span class="token import namespace" style=opacity:0.7>apache</span><span class="token import namespace punctuation" style=opacity:0.7;color:#393A34>.</span><span class="token import namespace" style=opacity:0.7>fory</span><span class="token import namespace punctuation" style=opacity:0.7;color:#393A34>.</span><span class="token import namespace" style=opacity:0.7>annotation</span><span class="token import namespace punctuation" style=opacity:0.7;color:#393A34>.</span><span class="token import class-name">ForyObject</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token annotation punctuation" style=color:#393A34>@ForyObject</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">evolving </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token boolean" style=color:#36acaa>false</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">StableMessage</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> id</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> name</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token punctuation" style=color:#393A34>}</span><br/></div></code></pre></div></div> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=meta-sharing>Meta Sharing<a href=#meta-sharing class=hash-link aria-label="Direct link to Meta Sharing" title="Direct link to Meta Sharing" translate=no></a></h2> |
| <p>To further reduce metadata costs, Fory introduces a class metadata sharing mechanism, which allows the metadata to be sent to the deserialization process only once.</p> |
| <p>Fory supports sharing type metadata (class name, field name, final field type information, etc.) between multiple serializations in a context (ex. TCP connection). This information will be sent to the peer during the first serialization in the context. Based on this metadata, the peer can rebuild the same deserializer, which avoids transmitting metadata for subsequent serializations and reduces network traffic pressure while supporting type forward/backward compatibility automatically.</p> |
| <h3 class="anchor anchorTargetStickyNavbar_Vzrq" id=using-meta-sharing>Using Meta Sharing<a href=#using-meta-sharing class=hash-link aria-label="Direct link to Using Meta Sharing" title="Direct link to Using Meta Sharing" translate=no></a></h3> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token comment" style=color:#999988;font-style:italic>// Fory.builder()</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// .withLanguage(Language.JAVA)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// .withRefTracking(false)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// // share meta across serialization.</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// .withMetaShare(true)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// Not thread-safe fory.</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token class-name">MetaWriteContext</span><span class="token plain"> writeContext </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> xxx</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain">fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>setMetaWriteContext</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">writeContext</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token keyword" style=color:#00009f>byte</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> bytes </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">o</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// Not thread-safe fory.</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token class-name">MetaReadContext</span><span class="token plain"> readContext </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> xxx</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain">fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>setMetaReadContext</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">readContext</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain">fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">bytes</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><br/></div></code></pre></div></div> |
| <h3 class="anchor anchorTargetStickyNavbar_Vzrq" id=thread-safe-meta-sharing>Thread-Safe Meta Sharing<a href=#thread-safe-meta-sharing class=hash-link aria-label="Direct link to Thread-Safe Meta Sharing" title="Direct link to Thread-Safe Meta Sharing" translate=no></a></h3> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token comment" style=color:#999988;font-style:italic>// Thread-safe fory</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token keyword" style=color:#00009f>byte</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> serialized </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>execute</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> f </span><span class="token operator" style=color:#393A34>-></span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> f</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>setMetaWriteContext</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">writeContext</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>return</span><span class="token plain"> f</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">beanA</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token comment" style=color:#999988;font-style:italic>// Thread-safe fory</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token class-name">Object</span><span class="token plain"> newObj </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>execute</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> f </span><span class="token operator" style=color:#393A34>-></span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> f</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>setMetaReadContext</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">readContext</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>return</span><span class="token plain"> f</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">serialized</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><br/></div></code></pre></div></div> |
| <p><strong>Note</strong>: <code>MetaWriteContext</code> and <code>MetaReadContext</code> are not thread-safe and cannot be reused across |
| instances of Fory or multiple threads. In cases of multi-threading, a separate pair of meta |
| contexts must be created for each Fory instance. If you need a different classloader, create a |
| separate <code>Fory</code> or <code>ThreadSafeFory</code> configured with that loader instead of switching loaders on an |
| existing instance.</p> |
| <p>For more details, please refer to the <a href=https://fory.apache.org/docs/specification/fory_java_serialization_spec#meta-share target=_blank rel="noopener noreferrer" class="">Meta Sharing specification</a>.</p> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=deserialize-unknown-classes>Deserialize Unknown Classes<a href=#deserialize-unknown-classes class=hash-link aria-label="Direct link to Deserialize Unknown Classes" title="Direct link to Deserialize Unknown Classes" translate=no></a></h2> |
| <p>Fory supports deserializing non-existent or unknown classes. This feature can be enabled by <code>ForyBuilder#deserializeUnknownClass(true)</code>.</p> |
| <p>When enabled and metadata sharing is enabled, Fory will store the deserialized data of this type in a lazy subclass of Map. By using the lazy map implemented by Fory, the rebalance cost of filling map during deserialization can be avoided, which further improves performance.</p> |
| <p>If this data is sent to another process and the class exists in this process, the data will be deserialized into the object of this type without losing any information.</p> |
| <p>If metadata sharing is not enabled, the new class data will be skipped and a <code>UnknownSkipClass</code> stub object will be returned.</p> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=copymap-object-from-one-type-to-another>Copy/Map Object from One Type to Another<a href=#copymap-object-from-one-type-to-another class=hash-link aria-label="Direct link to Copy/Map Object from One Type to Another" title="Direct link to Copy/Map Object from One Type to Another" translate=no></a></h2> |
| <p>Fory supports mapping objects from one type to another type.</p> |
| <p><strong>Notes:</strong></p> |
| <ol> |
| <li class="">This mapping will execute a deep copy. All mapped fields are serialized into binary and deserialized from that binary to map into another type.</li> |
| <li class="">All struct types must be registered with the same ID, otherwise Fory cannot map to the correct struct type. Be careful when you use <code>Fory#register(Class)</code>, because Fory will allocate an auto-grown ID which might be inconsistent if you register classes with different order between Fory instances.</li> |
| </ol> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">StructMappingExample</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>(</span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>this</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>this</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">Struct2</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>double</span><span class="token plain"> f3</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token class-name">ThreadSafeFory</span><span class="token plain"> fory1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token class-name">Fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>builder</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>withCompatibleMode</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">CompatibleMode</span><span class="token punctuation" style=color:#393A34>.</span><span class="token constant" style=color:#36acaa>COMPATIBLE</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>buildThreadSafeFory</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token class-name">ThreadSafeFory</span><span class="token plain"> fory2 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token class-name">Fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>builder</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>withCompatibleMode</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">CompatibleMode</span><span class="token punctuation" style=color:#393A34>.</span><span class="token constant" style=color:#36acaa>COMPATIBLE</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>buildThreadSafeFory</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> fory1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>register</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token keyword" style=color:#00009f>class</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> fory2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>register</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">Struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token keyword" style=color:#00009f>class</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>void</span><span class="token plain"> </span><span class="token function" style=color:#d73a49>main</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">String</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> args</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token plain"> struct1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>new</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>(</span><span class="token number" style=color:#36acaa>10</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> </span><span class="token string" style=color:#e3116c>"abc"</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Struct2</span><span class="token plain"> struct2 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">Struct2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> fory2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">fory1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct1</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Assert</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>assertEquals</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> struct1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Assert</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>assertEquals</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> struct1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> struct1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> fory1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">fory2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Assert</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>assertEquals</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Assert</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>assertEquals</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct1</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token punctuation" style=color:#393A34>}</span><br/></div></code></pre></div></div> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=deserialize-pojo-into-another-type>Deserialize POJO into Another Type<a href=#deserialize-pojo-into-another-type class=hash-link aria-label="Direct link to Deserialize POJO into Another Type" title="Direct link to Deserialize POJO into Another Type" translate=no></a></h2> |
| <p>Fory allows you to serialize one POJO and deserialize it into a different POJO. The different POJO means schema inconsistency. Users must configure Fory with <code>CompatibleMode</code> set to <code>org.apache.fory.config.CompatibleMode.COMPATIBLE</code>.</p> |
| <div class="language-java codeBlockContainer_Ckt0 theme-code-block" style=--prism-color:#393A34;--prism-background-color:#f6f8fa><div class=codeBlockContent_QJqH><pre tabindex=0 class="prism-code language-java codeBlock_bY9V thin-scrollbar" style=color:#393A34;background-color:#f6f8fa><code class=codeBlockLines_e6Vv><div class=token-line style=color:#393A34><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">DeserializeIntoType</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>(</span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>this</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>this</span><span class="token punctuation" style=color:#393A34>.</span><span class="token plain">f2 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>class</span><span class="token plain"> </span><span class="token class-name">Struct2</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>int</span><span class="token plain"> f1</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">String</span><span class="token plain"> f2</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>double</span><span class="token plain"> f3</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token class-name">ThreadSafeFory</span><span class="token plain"> fory </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token class-name">Fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>builder</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>withCompatibleMode</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">CompatibleMode</span><span class="token punctuation" style=color:#393A34>.</span><span class="token constant" style=color:#36acaa>COMPATIBLE</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>buildThreadSafeFory</span><span class="token punctuation" style=color:#393A34>(</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain" style=display:inline-block></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>public</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>static</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>void</span><span class="token plain"> </span><span class="token function" style=color:#d73a49>main</span><span class="token punctuation" style=color:#393A34>(</span><span class="token class-name">String</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> args</span><span class="token punctuation" style=color:#393A34>)</span><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>{</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token plain"> struct1 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> </span><span class="token keyword" style=color:#00009f>new</span><span class="token plain"> </span><span class="token class-name">Struct1</span><span class="token punctuation" style=color:#393A34>(</span><span class="token number" style=color:#36acaa>10</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> </span><span class="token string" style=color:#e3116c>"abc"</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token keyword" style=color:#00009f>byte</span><span class="token punctuation" style=color:#393A34>[</span><span class="token punctuation" style=color:#393A34>]</span><span class="token plain"> data </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>serialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">struct1</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token class-name">Struct2</span><span class="token plain"> struct2 </span><span class="token operator" style=color:#393A34>=</span><span class="token plain"> fory</span><span class="token punctuation" style=color:#393A34>.</span><span class="token function" style=color:#d73a49>deserialize</span><span class="token punctuation" style=color:#393A34>(</span><span class="token plain">data</span><span class="token punctuation" style=color:#393A34>,</span><span class="token plain"> </span><span class="token class-name">Struct2</span><span class="token punctuation" style=color:#393A34>.</span><span class="token keyword" style=color:#00009f>class</span><span class="token punctuation" style=color:#393A34>)</span><span class="token punctuation" style=color:#393A34>;</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"> </span><span class="token punctuation" style=color:#393A34>}</span><span class="token plain"></span><br/></div><div class=token-line style=color:#393A34><span class="token plain"></span><span class="token punctuation" style=color:#393A34>}</span><br/></div></code></pre></div></div> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=configuration>Configuration<a href=#configuration class=hash-link aria-label="Direct link to Configuration" title="Direct link to Configuration" translate=no></a></h2> |
| <table><thead><tr><th>Option<th>Description<th>Default<tbody><tr><td><code>compatibleMode</code><td><code>SCHEMA_CONSISTENT</code> or <code>COMPATIBLE</code><td><code>SCHEMA_CONSISTENT</code><tr><td><code>checkClassVersion</code><td>Check class schema consistency<td><code>false</code><tr><td><code>metaShareEnabled</code><td>Enable meta sharing<td><code>true</code> if Compatible mode<tr><td><code>scopedMetaShareEnabled</code><td>Scoped meta share per serialization<td><code>true</code> if Compatible mode<tr><td><code>deserializeUnknownClass</code><td>Handle non-existent or unknown classes<td><code>true</code> if Compatible mode<tr><td><code>metaCompressor</code><td>Compressor for meta compression<td><code>DeflaterMetaCompressor</code></table> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=best-practices>Best Practices<a href=#best-practices class=hash-link aria-label="Direct link to Best Practices" title="Direct link to Best Practices" translate=no></a></h2> |
| <ol> |
| <li class=""><strong>Use COMPATIBLE mode for evolving schemas</strong>: When classes may change between versions</li> |
| <li class=""><strong>Enable meta sharing for network communication</strong>: Reduces bandwidth for repeated serializations</li> |
| <li class=""><strong>Use consistent type IDs for struct mapping</strong>: Ensure same registration order or explicit IDs</li> |
| <li class=""><strong>Consider space overhead</strong>: Compatible mode adds metadata, balance with your requirements</li> |
| </ol> |
| <h2 class="anchor anchorTargetStickyNavbar_Vzrq" id=related-topics>Related Topics<a href=#related-topics class=hash-link aria-label="Direct link to Related Topics" title="Direct link to Related Topics" translate=no></a></h2> |
| <ul> |
| <li class=""><a class="" href=/docs/0.17/guide/java/configuration>Configuration</a> - All ForyBuilder options</li> |
| <li class=""><a class="" href=/docs/0.17/guide/java/cross_language>Cross-Language Serialization</a> - XLANG mode</li> |
| <li class=""><a class="" href=/docs/0.17/guide/java/troubleshooting>Troubleshooting</a> - Common schema issues</li> |
| </ul></div><footer class="theme-doc-footer docusaurus-mt-lg"><div class="row margin-top--sm theme-doc-footer-edit-meta-row"><div class="col noPrint_WFHX"><a href=https://github.com/apache/fory-site/tree/main/docs/guide/java/schema-evolution.md target=_blank rel="noopener noreferrer" class=theme-edit-this-page><svg fill=currentColor height=20 width=20 viewBox="0 0 40 40" class=iconEdit_Z9Sw aria-hidden=true><g><path d="m34.5 11.7l-3 3.1-6.3-6.3 3.1-3q0.5-0.5 1.2-0.5t1.1 0.5l3.9 3.9q0.5 0.4 0.5 1.1t-0.5 1.2z m-29.5 17.1l18.4-18.5 6.3 6.3-18.4 18.4h-6.3v-6.2z"/></g></svg>Edit this page</a></div><div class="col lastUpdated_JAkA"></div></div></footer></article><nav class="docusaurus-mt-lg pagination-nav" aria-label="Docs pages"><a class="pagination-nav__link pagination-nav__link--prev" href=/docs/0.17/guide/java/java_virtual_threads><div class=pagination-nav__sublabel>Previous</div><div class=pagination-nav__label>Virtual Threads</div></a><a class="pagination-nav__link pagination-nav__link--next" href=/docs/0.17/guide/java/advanced_features><div class=pagination-nav__sublabel>Next</div><div class=pagination-nav__label>Advanced Features</div></a></nav></div></div><div class="col col--3"><div class="tableOfContents_bqdL thin-scrollbar theme-doc-toc-desktop"><ul class="table-of-contents table-of-contents__left-border"><li><a href=#handling-class-schema-evolution class="table-of-contents__link toc-highlight">Handling Class Schema Evolution</a><ul><li><a href=#default-mode-schema_consistent class="table-of-contents__link toc-highlight">Default Mode: SCHEMA_CONSISTENT</a><li><a href=#compatible-mode class="table-of-contents__link toc-highlight">Compatible Mode</a><li><a href=#disable-evolution-for-stable-classes class="table-of-contents__link toc-highlight">Disable Evolution for Stable Classes</a></ul><li><a href=#meta-sharing class="table-of-contents__link toc-highlight">Meta Sharing</a><ul><li><a href=#using-meta-sharing class="table-of-contents__link toc-highlight">Using Meta Sharing</a><li><a href=#thread-safe-meta-sharing class="table-of-contents__link toc-highlight">Thread-Safe Meta Sharing</a></ul><li><a href=#deserialize-unknown-classes class="table-of-contents__link toc-highlight">Deserialize Unknown Classes</a><li><a href=#copymap-object-from-one-type-to-another class="table-of-contents__link toc-highlight">Copy/Map Object from One Type to Another</a><li><a href=#deserialize-pojo-into-another-type class="table-of-contents__link toc-highlight">Deserialize POJO into Another Type</a><li><a href=#configuration class="table-of-contents__link toc-highlight">Configuration</a><li><a href=#best-practices class="table-of-contents__link toc-highlight">Best Practices</a><li><a href=#related-topics class="table-of-contents__link toc-highlight">Related Topics</a></ul></div></div></div></div></main></div></div></div><footer class="theme-layout-footer footer footer--dark"><div class="container container-fluid"><div class="row footer__links"><div class="theme-layout-footer-column col footer__col"><div class=footer__title>Community</div><ul class="footer__items clean-list"><li class=footer__item><a href=https://lists.apache.org/list.html?dev@fory.apache.org target=_blank rel="noopener noreferrer" class=footer__link-item>Mailing list<svg width=13.5 height=13.5 aria-label="(opens in new tab)" class=iconExternalLink_nPIU><use href=#theme-svg-external-link /></svg></a><li class=footer__item><a href=https://join.slack.com/t/fory-project/shared_invite/zt-1u8soj4qc-ieYEu7ciHOqA2mo47llS8A target=_blank rel="noopener noreferrer" class=footer__link-item>Slack<svg width=13.5 height=13.5 aria-label="(opens in new tab)" class=iconExternalLink_nPIU><use href=#theme-svg-external-link /></svg></a><li class=footer__item><a href=https://twitter.com/ApacheFory target=_blank rel="noopener noreferrer" class=footer__link-item>Twitter<svg width=13.5 height=13.5 aria-label="(opens in new tab)" class=iconExternalLink_nPIU><use href=#theme-svg-external-link /></svg></a></ul></div><div class="theme-layout-footer-column col footer__col"><div class=footer__title>Docs</div><ul class="footer__items clean-list"><li class=footer__item><a class=footer__link-item href=/docs/start/install>Install</a><li class=footer__item><a class=footer__link-item href=/docs/start/usage>Usage</a><li class=footer__item><a class=footer__link-item href=/docs/introduction/benchmark>Benchmark</a></ul></div><div class="theme-layout-footer-column col footer__col"><div class=footer__title>Repositories</div><ul class="footer__items clean-list"><li class=footer__item><a href=https://github.com/apache/fory target=_blank rel="noopener noreferrer" class=footer__link-item>Apache Fory™<svg width=13.5 height=13.5 aria-label="(opens in new tab)" class=iconExternalLink_nPIU><use href=#theme-svg-external-link /></svg></a><li class=footer__item><a href=https://github.com/apache/fory-site target=_blank rel="noopener noreferrer" class=footer__link-item>Website<svg width=13.5 height=13.5 aria-label="(opens in new tab)" class=iconExternalLink_nPIU><use href=#theme-svg-external-link /></svg></a></ul></div></div><div class="footer__bottom text--center"><div class=margin-bottom--sm><a href=https://apache.org/ rel="noopener noreferrer" class=footerLogoLink_BH7S><img src=/img/asf_logo.svg alt="ASF Logo" class="footer__logo themedComponent_mlkZ themedComponent--light_NVdE" width=200 /><img src=/img/asf_logo.svg alt="ASF Logo" class="footer__logo themedComponent_mlkZ themedComponent--dark_xIcU" width=200 /></a></div><div class=footer__copyright><div> |
| <p> |
| Copyright © 2026 The Apache Software Foundation, Licensed under the Apache License, Version 2.0. <br/> |
| Apache Fory, Fory, Apache, the Apache Logo and the Apache Fory logo are either registered trademarks or trademarks of the Apache Software Foundation in the United States and/or other countries. |
| </p> |
| </div></div></div></div></footer></div></body> |
