Error at line -1 when using SimpleXml to parse xml

When parsing my XML files with Simple, I get errors like the following one:

org.simpleframework.xml.core.ValueRequiredException: 
Unable to satisfy ... on field 'id' private String Foo.id 
for class Foo at line -1

What do I need to change to get the real line number?

[EDIT] Here is a Gist: Demo for SimpleXml l开发者_如何学JAVAine number problem

I'm using simple-xml:2.6.1 and junit:4.9

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Depends on where it is run. If you run in JDK 1.5, witout StAX in the classpath this means you are using DOM, so you will always get -1 on an error. If you use JDK 1.5 or above with StAX in the classpath then StAX does not support line numbers (perhaps try a different lib, I recomment Woodstox).

[EDIT] If you want to try Woodstox and you use Maven, add this to your POM:

<dependency>
    <groupId>org.codehaus.woodstox</groupId>
    <artifactId>woodstox-core-asl</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.codehaus.woodstox</groupId>
    <artifactId>stax2-api</artifactId>
    <version>3.1.1</version>
</dependency>

This is the version which uses Apache License 2.0. If you prefer LGPL 2.1, replace -asl with -lgpl.