How to get a node value of JTree?

If you use DefaultMutableTreeNode's to build your tree, then that class has methods for getting enumerator's that return all the nodes in various orders.

You start with your JTree, let's says it's called tree.

From JTree you can get the TreeModel :

    TreeModel model = tree.getModel();

From the Model you can get the root object :

    Object obj = model.getRoot();

If we assume that the root object is a DefaultMutableTreeNode we can cast it, thus :

    DefaultMutableTreeNode node = (DefaultMutableTreeNode) obj;

Now that we have the root as a node we can get an enumeration of the entire tree :

    Enumeration e = node.depthFirstEnumeration();

or

    Enumeration e = node.breadthFirstEnumeration();

Then we can use the enumeratoin to get each node :

    while (e.hasModeElements){
        ...etc
    }

Hope this helps.

Thanks for expanding on my comment :)
But remember we can't always assume the root node is a DefaultMutableTreeNode.

Thanks for wamoz! At the same time, I also want to thanks to ozymandias! I did not have time to try this, but I will implement this later. I also did not have enough time to study the documentation in fact. Now I understand JTree more.

Re-reading my response I think I owe you an apology, because being right is no excuse for (my) bad manners.

Don't let your employer bully you, Fungho. You NEED time to study the documentation... the Java libraries, though layered, cohesive and IMHO rather well designed, are vast.

The Java Trails are a extensive and form both a very good introduction to basic material and a great way to re-familiarise oneself with the how-to of core technologies. I recommend that you download them.

They are available as either a Windows help file or as a web of linked HTML files. I prefer the HTML version. The first thing I do at any workplace is install them (along with the documentation for all the Java libraries I install) on a webserver so that everyone can have high-speed access. At home I run a webserver for this same purpose.

In respect of TreeModels, you can implement your own. To do anything even a little advanced you will almost certainly end up doing so; this allows you to add all sorts of extra properties and methods both to the tree model and to the node objects it organises.