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<TITLE>Exporting the Preferences in a Preference Node (Java Developers Almanac Example)
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<A HREF="../java.util.prefs/pkg.html">java.util.prefs</A><font color="#666666" class="xsmall-font">
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<B><A HREF="../java.util.prefs/pkg.html#Importing and Exporting">Importing and Exporting</A></B><font color="#666666" class="xsmall-font">
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<h3>e419. Exporting the Preferences in a Preference Node</h3>
This example demonstrates how to export the preferences in a
preference node to a file. The exported values can be imported using
<code>Preferences.importPreferences()</code> (see
<a href="../java.util.prefs/Import.html" class="eglink"><b>e418</b> Importing Preferences</a>). The format of the exported data
is XML.
<P> The exported data contains the path of the node that was
exported. When the data is later imported, the preferences will be
added to the node with exactly the same path.
<pre> // Retrieve the user preference node for the package java.lang
Preferences prefs = Preferences.userNodeForPackage(<font color="#0066ff"><i>String.class</i></font>);
// Save some values
prefs.put(<font color="#0066ff"><i>"myString"</i></font>, <font color="#0066ff"><i>"a string"</i></font>); // String
prefs.putBoolean(<font color="#0066ff"><i>"myBoolean"</i></font>, <font color="#0066ff"><i>true</i></font>); // boolean
prefs.putInt(<font color="#0066ff"><i>"myInt"</i></font>, <font color="#0066ff"><i>123</i></font>); // int
prefs.putLong(<font color="#0066ff"><i>"myLong"</i></font>, <font color="#0066ff"><i>123L</i></font>); // long
prefs.putFloat(<font color="#0066ff"><i>"myFloat"</i></font>, <font color="#0066ff"><i>12.3F</i></font>); // float
prefs.putDouble(<font color="#0066ff"><i>"myDouble"</i></font>, <font color="#0066ff"><i>12.3</i></font>); // double
byte[] bytes = new byte[<font color="#0066ff"><i>10</i></font>];
prefs.putByteArray(<font color="#0066ff"><i>"myByteArray"</i></font>, <font color="#0066ff"><i>bytes</i></font>); // byte[]
try {
// Export the node to a file
prefs.exportNode(new FileOutputStream(<font color="#0066ff"><i>"output.xml"</i></font>));
} catch (IOException e) {
} catch (BackingStoreException e) {
}
</pre>
The code above generates the following XML data:
<pre> <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE preferences SYSTEM 'http://java.sun.com/dtd/preferences.dtd'>
<preferences EXTERNAL_XML_VERSION="1.0">
<root type="user">
<map />
<node name="java">
<map />
<node name="lang">
<map>
<entry key="myString" value="a string" />
<entry key="myBoolean" value="true" />
<entry key="myInt" value="123" />
<entry key="myLong" value="123" />
<entry key="myFloat" value="12.3" />
<entry key="myDouble" value="12.3" />
<entry key="myByteArray" value="AAAAAAAAAAAAAA==" />
</map>
</node>
</node>
</root>
</preferences>
</pre>
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<b>Related Examples</b></font></td>
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e418. <a class="eglink" href="Import.html?l=rel">
Importing Preferences
</a>
<br>
e420. <a class="eglink" href="ExportTree.html?l=rel">
Exporting the Preferences in a Subtree of Preference Nodes
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See also:
<a class="eglink" href="/egs/java.util.prefs/pkg.html?l=rel#Events">
Events
</a>
<a class="eglink" href="/egs/java.util.prefs/pkg.html?l=rel#Nodes">
Nodes
</a>
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