The content of element type "properties" must match "(comment?,entry*)".

I'm trying to make my Java XML properties file a little more human-readable by breaking the entries into blocks. Evidently my assumptions on how to do this were wrong. Here are the error, cause, and solution:

Error:

java.util.InvalidPropertiesFormatException: org.xml.sax.SAXParseException: The content of element type "properties" must match "(comment?,entry*)".

Cause:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
 
    <comment>---SQL settings---</comment>
    <entry key="SQLJNDIName">SQLDataSource</entry>
    <entry key="SQLServerName">server01</entry>
    <entry key="SQLPortNumber">12345</entry>
    <entry key="SQLDatabaseName">db01</entry>
    <entry key="SQLUser">user01</entry>
    <entry key="SQLPassword">changeme</entry>
    <entry key="SQLTableOwner">dbo</entry>
 
    <comment>---TEST settings---</comment>
    <entry key="TEST">TEST</entry>
 
</properties>

Solution: I changed the comment elements into XML comments, and it worked.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
 
    <!--SQL settings-->
    <entry key="SQLJNDIName">SQLDataSource</entry>
    <entry key="SQLServerName">server01</entry>
    <entry key="SQLPortNumber">12345</entry>
    <entry key="SQLDatabaseName">db01</entry>
    <entry key="SQLUser">user01</entry>
    <entry key="SQLPassword">changeme</entry>
    <entry key="SQLTableOwner">dbo</entry>
 
    <!--TEST settings-->
    <entry key="TEST">TEST</entry>
 
</properties>