I want to convert a Treepath into a String so that I can use it for IO operations ... How can I do it ?

Suppose I have a Treepath variable like this:-

TreePath path = m_tree.getPathForLocation(x, y)

Thanks in advance

This depends on what kind of Objects the Tree is composed of. If they're Strings this isn't too hard, but if they are some complex class that doesn't have a simple string representation...
TreePath is Serializable (provided its constituent Objects are Serlializable), so you just want to do I/O on it without needing to control the format yourself, you could simply write it to an ObjectOutputStream with a single writeObject call.