| // |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| // |
| |
| = DevFaqDotSettingsFiles |
| :jbake-type: wiki |
| :jbake-tags: wiki, devfaq, needsreview |
| :jbake-status: published |
| |
| === What are .settings files? |
| |
| `.settings` files are similar to [[DevFaqInstanceDataObject| `.instance` files]], |
| with the difference that they are XML format, and can contain serialized data rather than just default instances. |
| |
| Since the introduction of [link:http://bits.netbeans.org/dev/javadoc/org-openide-util/org/openide/util/NbPreferences.html[http://bits.netbeans.org/dev/javadoc/org-openide-util/org/openide/util/NbPreferences.html] `NbPreferences`] to replace [link:http://bits.netbeans.org/dev/javadoc/org-openide-options/org/openide/options/SystemOption.html[http://bits.netbeans.org/dev/javadoc/org-openide-options/org/openide/options/SystemOption.html] `SystemOption`], |
| very little new code uses these files, and they should be considered semi-deprecated. They are difficult and error-prone to use, and have a fair amount of overhead. The Window System still requires them to be used to persist the state of opened windows/tabs (caret position, what file is opened, or other state that should be restored when reopening a [link:http://bits.netbeans.org/dev/javadoc/org-openide-windows/org/openide/windows/TopComponent.html[http://bits.netbeans.org/dev/javadoc/org-openide-windows/org/openide/windows/TopComponent.html] `TopComponent`] after a restart) across application runs. |
| |
| A `.settings` file can encode the entire parent class and interface hierarchy of the object it represents, so that a query about _whether an object of a given type is present_ (such as using `link:http://bits.netbeans.org/dev/javadoc/org-openide-util-lookup/org/openide/util/lookup/Lookups.html#forPath(java.lang.String)[Lookups.forPath]("path/to/folder").allItems()`) can be answered without actually creating an instance of the object. |
| |
| Settings files are also useful if you are declaring some objects in a layer file (see link:DevFaqModulesLayerFile.html[DevFaqModulesLayerFile]) _and intend to write them back out to disk after they have been modified in-memory_ (note this involves writing ugly and inefficient hexadecimal-encoded serialized data into XML files - if the object is a singleton, using `link:http://bits.netbeans.org/dev/javadoc/org-openide-util/org/openide/util/NbPreferences.html[NbPreferences]` will be both more efficient and more readable). |
| |
| ==== Example |
| |
| [source,xml] |
| ---- |
| |
| <?xml version="1.0"?> |
| <!DOCTYPE settings PUBLIC "-//NetBeans//DTD Session settings 1.0//EN" |
| "link:http://www.netbeans.org/dtds/sessionsettings-1_0.dtd[http://www.netbeans.org/dtds/sessionsettings-1_0.dtd]"> |
| <settings version="1.0"> |
| <module name="org.netbeans.core.io.ui/1" spec="1.6"/> |
| <instanceof class="org.openide.windows.TopComponent"/> |
| <instanceof class="org.netbeans.core.io.ui.IOWindow$IOWindowImpl"/> |
| <serialdata class="org.netbeans.core.io.ui.IOWindow$IOWindowImpl"> |
| ACED0005737200296F72672E6F70656E6964652E7... |
| </serialdata> |
| </settings> |
| ---- |
| |
| === Apache Migration Information |
| |
| The content in this page was kindly donated by Oracle Corp. to the |
| Apache Software Foundation. |
| |
| This page was exported from link:http://wiki.netbeans.org/DevFaqDotSettingsFiles[http://wiki.netbeans.org/DevFaqDotSettingsFiles] , |
| that was last modified by NetBeans user Jglick |
| on 2010-06-14T21:40:32Z. |
| |
| |
| *NOTE:* This document was automatically converted to the AsciiDoc format on 2018-01-10, and needs to be reviewed. |