JTree sorting problem, how to sort

Question

here is my code:
DefaultMutableTreeNode root=new DefaultMutableTreeNode("root");
                         DefaultMutableTreeNode childone=new DefaultMutableTreeNode("id");
                         DefaultMutableTreeNode person1=new DefaultMutableTreeNode("david");
                         DefaultMutableTreeNode p11=new DefaultMutableTreeNode("java programming");
                         DefaultMutableTreeNode p12=new DefaultMutableTreeNode("maths");
                         DefaultMutableTreeNode p13=new DefaultMutableTreeNode("c programming");
                         person1.add(p11);
                         person1.add(p12);
                         person1.add(p13);
                         childone.add(person1);
                         DefaultMutableTreeNode person3=new DefaultMutableTreeNode("ann");
                         DefaultMutableTreeNode p31=new DefaultMutableTreeNode("georgian");
                         DefaultMutableTreeNode p32=new DefaultMutableTreeNode("english");
                         DefaultMutableTreeNode p33=new DefaultMutableTreeNode("russian");
                         person3.add(p31);
                         person3.add(p32);
                         person3.add(p33);
                         childone.add(person3);
                         DefaultMutableTreeNode person2=new DefaultMutableTreeNode("merab");
                         DefaultMutableTreeNode p21=new DefaultMutableTreeNode("veterinar");
                         DefaultMutableTreeNode p22=new DefaultMutableTreeNode("building");
                         person2.add(p21);
                         person2.add(p22);
                         childone.add(person2);
                         DefaultMutableTreeNode person4=new DefaultMutableTreeNode("maia");
                         DefaultMutableTreeNode p41=new DefaultMutableTreeNode("medicine");
                         DefaultMutableTreeNode p42=new DefaultMutableTreeNode("pediatri");
                         DefaultMutableTreeNode p43=new DefaultMutableTreeNode("aaaa");
                         p41.add(p42);
                         p41.add(p43);
                         person4.add(p41);
                         childone.add(person4);
                         DefaultMutableTreeNode childtwo=new DefaultMutableTreeNode("fullname");
                         DefaultMutableTreeNode c1=new DefaultMutableTreeNode("merab");
                         DefaultMutableTreeNode c2=new DefaultMutableTreeNode("maia");
                         DefaultMutableTreeNode c3=new DefaultMutableTreeNode("ann");
                         DefaultMutableTreeNode c4=new DefaultMutableTreeNode("david");
                         childtwo.add(c1);
                         childtwo.add(c2);
                         childtwo.add(c3);
                         childtwo.add(c4);
                         DefaultMutableTreeNode childthree=new DefaultMutableTreeNode("email");
                         DefaultMutableTreeNode d1=new DefaultMutableTreeNode("[email protected]");
                         DefaultMutableTreeNode d2=new DefaultMutableTreeNode("[email protected]");
                         DefaultMutableTreeNode d3=new DefaultMutableTreeNode("[email protected]");
                         childthree.add(d1);
                         childthree.add(d2);
                         childthree.add(d3);
                         root.add(childthree);
                         root.add(childone);
                         root.add(childthree);
                         jTree1 = new JTree(root);
                         jScrollPane1.setViewportView(jTree1);
                     //   DefaultTreeModel ddd=(DefaultTreeModel)jTree1.getModel();
                        Comparator<DefaultMutableTreeNode> comp=new Comparator<DefaultMutableTreeNode>() {
                             public int compare(DefaultMutableTreeNode o1,DefaultMutableTreeNode o2) {
                                  return o1.toString().compareTo(o2.toString());
                        ArrayList<DefaultMutableTreeNode> arr=Collections.list(root.children());
                         Collections.sort(arr,comp);
                         root.removeAllChildren();
                        for(int i=0;i<arr.size();i++)
                             root.add(arr.get(i));now i want to sort all nodes and leafs that contains this tree , how should i do that? can anyone correct this code so that it sorts all data in this jtree?

Answer 1

We may extend DefaultMutableTreeNode to implement Comparable
and override insert so that the relevant nodes are sorted after each insert:
* TreeSort.java
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
public class TreeSort extends JFrame {
    private JTree jTree1;
    private JScrollPane jScrollPane1;
    public TreeSort() {
        super("TreeSort");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(400,300);
        setLocationRelativeTo(null);
        MyNode root = new MyNode("root");
        MyNode childone = new MyNode("id");
        MyNode person1 = new MyNode("david");
        MyNode p11 = new MyNode("java programming");
        MyNode p12 = new MyNode("maths");
        MyNode p13 = new MyNode("c programming");
        person1.add(p11);
        person1.add(p12);
        person1.add(p13);
        childone.add(person1);
        MyNode person3 = new MyNode("ann");
        MyNode p31 = new MyNode("georgian");
        MyNode p32 = new MyNode("english");
        MyNode p33 = new MyNode("russian");
        person3.add(p31);
        person3.add(p32);
        person3.add(p33);
        childone.add(person3);
        MyNode person2 = new MyNode("merab");
        MyNode p21 = new MyNode("veterinar");
        MyNode p22 = new MyNode("building");
        person2.add(p21);
        person2.add(p22);
        childone.add(person2);
        MyNode person4 = new MyNode("maia");
        MyNode p41 = new MyNode("medicine");
        MyNode p42 = new MyNode("pediatri");
        MyNode p43 = new MyNode("aaaa");
        p41.add(p42);
        p41.add(p43);
        person4.add(p41);
        childone.add(person4);
        MyNode childtwo = new MyNode("fullname");
        MyNode c1 = new MyNode("merab");
        MyNode c2 = new MyNode("maia");
        MyNode c3 = new MyNode("ann");
        MyNode c4 = new MyNode("david");
        childtwo.add(c1);
        childtwo.add(c2);
        childtwo.add(c3);
        childtwo.add(c4);
        MyNode childthree = new MyNode("email");
        MyNode d1 = new MyNode("[email protected]");
        MyNode d2 = new MyNode("[email protected]");
        MyNode d3 = new MyNode("[email protected]");
        childthree.add(d1);
        childthree.add(d2);
        childthree.add(d3);
        root.add(childtwo);
        root.add(childone);
        root.add(childthree);
        jTree1 = new JTree(root);
        jScrollPane1 = new JScrollPane();
        jScrollPane1.setViewportView(jTree1);
        add(jScrollPane1);
    public static void main(final String[] args) {
        Runnable gui = new Runnable() {
            public void run() {
                new TreeSort().setVisible(true);
        //GUI must start on EventDispatchThread:
        SwingUtilities.invokeLater(gui);
class MyNode extends DefaultMutableTreeNode implements Comparable {
    public MyNode(String name) {
        super(name);
    @Override
    public void insert(final MutableTreeNode newChild, final int childIndex) {
        super.insert(newChild, childIndex);
        Collections.sort(this.children);
    public int compareTo(final Object o) {
        return this.toString().compareToIgnoreCase(o.toString());
}Edited by: Andre_Uhres on Nov 22, 2008 3:47 PM
There seems to be a small bug in your original code: childthree is added twice and childtwo isn't added at all.