How to construct a relative path in Java from two absolute paths (or URLs)?

Question

Given two absolute paths, e.g.

/var/data/stuff/xyz.dat
/var/data

How can one create a relative path that uses the second path as its base?

Answer 1

If you're writing a Maven plugin, you can use Plexus' PathTool:

import org.codehaus.plexus.util.PathTool;

String relativeFilePath = PathTool.getRelativeFilePath(file1, file2);