Using Groovy to update/generate XML file

Recently when I refactored the Android framework in my work, I found I need to generate eclipse .classpath file based on the library file.
I found using Groovy XML library is a lot easier to do this job compare to Java.

1. Add a new library to the current .classpath file.
Problem:  You have a Eclipse .classpath file, which is XML, you need to add another jar file in the class path. for example, adding following into the .classpath:
Solution:
 If you want to write the output to file, use the following code snippet:

There is another method to print XML, using XmlNodePrinter, like:
But I found using XmlNodePrinter will not generate line break, and no xml header either.

2. Generate a new .classpath file
Problem:  iterate the libs folder, add all the jar file name into the .classpath file.
Solution: