| <html><head> |
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| <title>Chapter 6. Metadata</title><link rel="stylesheet" href="css/docbook.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.72.0"><link rel="start" href="manual.html" title="Apache OpenJPA User's Guide"><link rel="up" href="ref_guide.html" title="Part 3. Reference Guide"><link rel="prev" href="ref_guide_perfpack_eager.html" title="7. Eager Fetching"><link rel="next" href="ref_guide_meta_jpa.html" title="2. Additional JPA Metadata"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 6. |
| Metadata |
| </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ref_guide_perfpack_eager.html">Prev</a> </td><th width="60%" align="center">Part 3. Reference Guide</th><td width="20%" align="right"> <a accesskey="n" href="ref_guide_meta_jpa.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en" id="ref_guide_meta"><div class="titlepage"><div><div><h2 class="title"><a name="ref_guide_meta"></a>Chapter 6. |
| Metadata |
| </h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="ref_guide_meta.html#ref_guide_meta_factory">1. |
| Metadata Factory |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_jpa.html">2. |
| Additional JPA Metadata |
| </a></span></dt><dd><dl><dt><span class="section"><a href="ref_guide_meta_jpa.html#ref_guide_meta_jpa_datastoreid">2.1. |
| Datastore Identity |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_jpa.html#ref_guide_meta_jpa_version">2.2. |
| Surrogate Version |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_jpa.html#ref_guide_meta_jpa_persistent">2.3. |
| Persistent Field Values |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_jpa.html#ref_guide_meta_jpa_persistent_coll">2.4. Persistent Collection Fields</a></span></dt><dt><span class="section"><a href="ref_guide_meta_jpa.html#ref_guide_meta_jpa_persistent_map">2.5. Persistent Map Fields</a></span></dt></dl></dd><dt><span class="section"><a href="ref_guide_meta_ext.html">3. |
| Metadata Extensions |
| </a></span></dt><dd><dl><dt><span class="section"><a href="ref_guide_meta_ext.html#ref_guide_meta_class">3.1. |
| Class Extensions |
| </a></span></dt><dd><dl><dt><span class="section"><a href="ref_guide_meta_ext.html#fetch-groups">3.1.1. |
| Fetch Groups |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#data-cache">3.1.2. |
| Data Cache |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#detached-state-field">3.1.3. |
| Detached State |
| </a></span></dt></dl></dd><dt><span class="section"><a href="ref_guide_meta_ext.html#ref_guide_meta_field">3.2. |
| Field Extensions |
| </a></span></dt><dd><dl><dt><span class="section"><a href="ref_guide_meta_ext.html#dependent">3.2.1. |
| Dependent |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#load-fetch-group">3.2.2. |
| Load Fetch Group |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#lrs">3.2.3. |
| LRS |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#inverse-logical">3.2.4. |
| Inverse-Logical |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#read-only">3.2.5. |
| Read-Only |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#type">3.2.6. |
| Type |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#externalizer">3.2.7. |
| Externalizer |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#factory">3.2.8. |
| Factory |
| </a></span></dt><dt><span class="section"><a href="ref_guide_meta_ext.html#external-values">3.2.9. |
| External Values |
| </a></span></dt></dl></dd><dt><span class="section"><a href="ref_guide_meta_ext.html#ref_guide_meta_example">3.3. |
| Example |
| </a></span></dt></dl></dd></dl></div><p> |
| The JPA Overview covers JPA metadata in <a href="jpa_overview_meta.html" title="Chapter 5. Metadata">Chapter 5, <i xmlns:xlink="http://www.w3.org/1999/xlink"> |
| Metadata |
| </i></a>. |
| This chapter discusses OpenJPA's extensions to standard JPA metadata. |
| </p><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="ref_guide_meta_factory"></a>1. |
| Metadata Factory |
| </h2></div></div></div><a class="indexterm" name="d0e22805"></a><p> |
| The <a href="ref_guide_conf_openjpa.html#openjpa.MetaDataFactory" title="5.42. openjpa.MetaDataFactory"><code class="literal">openjpa.MetaDataFactory |
| </code></a> configuration property controls metadata loading and storing. |
| This property takes a plugin string (see |
| <a href="ref_guide_conf_plugins.html" title="4. Plugin Configuration">Section 4, “ |
| Plugin Configuration |
| ”</a>) describing a concrete |
| <a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/meta/MetaDataFactory.html" target="_top"> |
| <code class="classname">org.apache.openjpa.meta.MetaDataFactory</code></a> |
| implementation. A metadata factory can load mapping information as well as |
| persistence metadata, or it can leave mapping information to a separate |
| <span class="emphasis"><em>mapping factory</em></span> (see |
| <a href="ref_guide_mapping_factory.html" title="5. Mapping Factory">Section 5, “ |
| Mapping Factory |
| ”</a>). OpenJPA recognizes the |
| following built-in metadata factories: |
| </p><div class="itemizedlist"><ul type="disc"><li><p> |
| <code class="literal">jpa</code>: Standard JPA metadata. This is an alias for the |
| <a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/persistence/PersistenceMetaDataFactory.html" target="_top"> |
| <code class="classname"> |
| org.apache.openjpa.persistence.PersistenceMetaDataFactory</code></a>. |
| </p></li></ul></div><p> |
| JPA has built-in settings for listing your persistent classes, which |
| the <a href="jpa_overview_persistence.html#jpa_overview_persistence_xml" title="1. persistence.xml">JPA Overview</a> describes. |
| OpenJPA supports these JPA standard settings by translating them into its own |
| internal metadata factory properties. Each internal property represents a |
| different mechanism for locating persistent types; you can choose the mechanism |
| or combination of mechanisms that are most convenient. See |
| <a href="ref_guide_pc.html#ref_guide_pc_pcclasses" title="1. Persistent Class List">Section 1, “ |
| Persistent Class List |
| ”</a> for a discussion of when it is |
| necessary to list your persistent classes. |
| </p><div class="itemizedlist"><ul type="disc"><li><p> |
| <code class="literal">Types</code>: A semicolon-separated list of fully-qualified |
| persistent class names. |
| </p></li><li><p> |
| <code class="literal">Resources</code>: A semicolon-separated list of resource paths to |
| metadata files or jar archives. Each jar archive will be scanned for |
| annotated JPA entities. |
| </p></li><li><p> |
| <code class="literal">URLs</code>: A semicolon-separated list of URLs of metadata files |
| or jar archives. Each jar archive will be scanned for annotated JPA |
| entities. |
| </p></li><li><p> |
| <code class="literal">ClasspathScan</code>: A semicolon-separated list of directories or |
| jar archives listed in your classpath. Each directory and jar archive will be |
| scanned for annotated JPA entities. |
| </p></li></ul></div><div class="example"><a name="ref_guide_meta_stdfactoryex"></a><p class="title"><b>Example 6.1. |
| Setting a Standard Metadata Factory |
| </b></p><div class="example-contents"><pre class="programlisting"> |
| <property name="openjpa.MetaDataFactory" value="jpa(ClasspathScan=build;lib.jar)"/> |
| </pre></div></div><br class="example-break"><div class="example"><a name="ref_guide_meta_customfactoryex"></a><p class="title"><b>Example 6.2. |
| Setting a Custom Metadata Factory |
| </b></p><div class="example-contents"><pre class="programlisting"> |
| <property name="openjpa.MetaDataFactory" value="com.xyz.CustomMetaDataFactory"/> |
| </pre></div></div><br class="example-break"></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ref_guide_perfpack_eager.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ref_guide.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ref_guide_meta_jpa.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">7. |
| Eager Fetching |
| </td><td width="20%" align="center"><a accesskey="h" href="manual.html">Home</a></td><td width="40%" align="right" valign="top"> 2. |
| Additional JPA Metadata |
| </td></tr></table></div></body></html> |
