Java Swing Tree Model Program :- Model Program Phase 2

import java.io.File;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;

/**
 *
 * @author Student
 */
public class MyTreeModel implements TreeModel {

    private final String rootPath = "C://WINDOWS";

    public Object getRoot() {   // call first time
        MyFile root = new MyFile(rootPath);
        return root;

    }

    public Object getChild(Object parent, int index) {          //it run asmany times as the value return by getChildCount()
        MyFile myParent = (MyFile) parent;
        File[] childFiles = myParent.listFiles();
        MyFile child = new MyFile(childFiles[index]);

        return child;

    }

    public int getChildCount(Object parent) { //
        MyFile myParent = (MyFile) parent;
        File[] childFiles = myParent.listFiles();
        if (childFiles != null) {
            return childFiles.length;
        } else {
            return 0;
        }

    }

    public boolean isLeaf(Object node) {              //2nd time and accept object send by getRoot() here node return type is MyFile
        MyFile myNode = (MyFile) node;
        return myNode.isFile();
    }

    public void valueForPathChanged(TreePath path, Object newValue) {
        System.out.println("path="+path);
        System.out.println("newvalue"+newValue);
    }


    public int getIndexOfChild(Object parent, Object child) {
        int index;
        MyFile childParent= (MyFile)parent;
       MyFile Child1=(MyFile)child;
       File[]listFiles=childParent.listFiles();
       for( index=0;index<listFiles.length;index++){
           if(listFiles[index].equals(Child1.getPath())){
               return (index);
           
           }
       }


return 0;
    }

    public void addTreeModelListener(TreeModelListener l) {                         //not used by tree models
    }

    public void removeTreeModelListener(TreeModelListener l) {                      //not used by tree models
    }
}