Meta-Data - JDO
JDO defines XML MetaData in jdo files as well as orm files. As always with XML, the metadata must match the defined DTD/XSD for that file type. This section describes the content of the jdo files. The content of orm files can be found here. All jdo files must contain a valid DTD/DOCTYPE specification. You can use PUBLIC or SYSTEM versions of these.
Here are a few examples valid for jdo files with DTD specifications
<!DOCTYPE jdo PUBLIC
"-//The Apache Software Foundation//DTD Java Data Objects Metadata 3.2//EN"
"https://db.apache.org/jdo/xmlns/jdo\_3\_2.dtd">
or
<!DOCTYPE jdo SYSTEM "file:/javax/jdo/jdo.dtd">
Here is an example valid for jdo files with XSD specification
<?xml version="1.0" encoding="UTF-8" ?>
<jdo xmlns="https://db.apache.org/jdo/xmlns/jdo"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="https://db.apache.org/jdo/xmlns/jdo https://db.apache.org/jdo/xmlns/jdo\_3\_2.xsd" version="3.2">
...
</jdo>
Your MetaData should match either the DTD or the XSD specification.