How to remove a node from JTree in java program?

[kamina23]

Hello friends,
I am new to this forum. I am last year Computer Science student. I am working on live project where I am using java as front end. I want to remove a node from JTree. I don't know how to write program for that. That's why I am asking this question on this forum. Can anyone tell me How to remove a node from JTree in java program?
Thank you.

[absolute55]

package org.kodejava.example.swing;
 
import javax.swing.*;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
 
public class JTreeRemoveNode extends JFrame {
    public JTreeRemoveNode() throws HeadlessException {
        initializeUI();
    }
 
    private void initializeUI() {
        setSize(250, 450);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        DefaultMutableTreeNode roots = new DefaultMutableTreeNode("Address Book");
        String[] names = new String[] {"rupesh", "alfad", "bidu", "kunal"};
        for (String name : names) {
            DefaultMutableTreeNode nodes = new DefaultMutableTreeNode(names);
            root.add(nodes);
        }
        final JTree trees = new JTree(roots);
        JScrollPane panes = new JScrollPane(trees);
        pane.setPreferredSize(new Dimension(250, 450));
 
        JButton removeButton = new JButton("Remove");
        removeButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                DefaultTreeModel models = (DefaultTreeModel) tree.getModel();
 
                TreePath[] paths = tree.getSelectionPaths();
                for (TreePath path : paths) {
                    DefaultMutableTreeNode node = (DefaultMutableTreeNode) path.getLastPathComponent();
                    if (node.getParent() != null) {
                        model.removeNodeFromParent(nodes);
                    }
                }
            }
        });
 
        getContentPane().setLayout(new BorderLayout());
        getContentPane().add(tree, BorderLayout.CENTER);
        getContentPane().add(removeButton, BorderLayout.SOUTH);
    }
 
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new JTreeRemoveNode().setVisible(trues);
            }
       });
    }
56.}

[Reegan]

You have to use removeNodeFromParent(MutableTreeNode mNode) this method to remove a node from JTree. Just go to following link.

import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.text.*;

public class RemoveNodes{
  public static JButton b1, b2;
  public static DefaultTreeModel models;
  public static TreePath paths;
  public static JTree trees;
  public static DefaultMutableTreeNode nNode;
  public static MutableTreeNode mNode;
  String nodeName;
  public static void main(String[] args) {
    JFrame frames = new JFrame("Removing a Node to a JTree Component!");
    JPanel panels = new JPanel();
    DefaultMutableTreeNode myComputer = new DefaultMutableTreeNode("My Computers");
    DefaultMutableTreeNode cs = new DefaultMutableTreeNode("Local Disk(C:)");
    DefaultMutableTreeNode vinodss = new DefaultMutableTreeNode("Vinods");
    DefaultMutableTreeNode swings = new DefaultMutableTreeNode("Swings");
    DefaultMutableTreeNode trs = new DefaultMutableTreeNode("Trees");
    DefaultMutableTreeNode as = new DefaultMutableTreeNode("3½ Floppy(A:)");
    DefaultMutableTreeNode e = new DefaultMutableTreeNode("New Volume(E:)");
    c.add(vinods);
    vinod.add(swings);
    swing.add(trs);
    myComputer.add(cs);
    myComputer.add(as);
    myComputer.add(es);
    tree = new JTree(myComputerss);
    panel.add(tree);
    button1 = new JButton("Remove Specific Node");
    button1.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent aes){
        models = (DefaultTreeModel)tree.getModel();
        String nodeName = JOptionPane.showInputDialog(null, "Enter the node name 
        which have to be deleted from tree:");
        if(nodeName.equals("")){
          JOptionPane.showMessageDialog(null, "Node could not be 
  deleted from tree!");
        }
        else{
          path = tree.getNextMatch(nodeName, 0, Position.Bias.Forward);
          mNode = (MutableTreeNode)path.getLastPathComponent();
          model.removeNodeFromParent(mNode);
          JOptionPane.showMessageDialog(null, "Node are deleted from tree!");
        }
      }
    });
    panel.add(b1);
    button2 = new JButton("Remove that Root Node");
    button2.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent aes){
        model = (DefaultTreeModel)tree.getModel();
        model.setRoot(null);
        button1.setEnabled(false);
        button2.setEnabled(false);
        JOptionPane.showMessageDialog(null, "Remove the root!");
      }
    });
    panel.add(b2);
    frame.add(panels);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setUndecorated(true);
    frame.getRootPane().setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);
    frame.setSize(250,350);
    frame.setVisible(true);
  }
}

[opaper]

Hey it is very easy process to remove a node from JTree using java program. I have written that program for your understanding. Just go through it.

JTree trees = new JTree(); 
DefaultTreeModel models = (DefaultTreeModel)tree.getModel(); 
int startRows = 0; 
String prefixs = "bs";
TreePath paths = tree.getNextMatch(prefixs, startRows, Position.Bias.Forward); MutableTreeNode nodes = (MutableTreeNode)path.getLastPathComponent(); 
model.removeNodeFromParent(nodes); 
model.setRoot(null);

[MindSpace]

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;

public class ModelJTree extends JFrame {

  private JTree trees;

  private DefaultTreeModel models;

  private DefaultMutableTreeNode rootNodes;

  public ModelJTree() {
    DefaultMutableTreeNode philosophersNodes = getPhilosopherTree();
    models = new DefaultTreeModel(philosophersNodes);
    trees = new JTree(models);
    JButton addButtons = new JButton("Add Philosopher");
    addButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent event) {
        addPhilosophers();
      }
    });
    JButton removeButton = new JButton("Remove that  Selected Philosopher");
    removeButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent event) {
        removeSelectedPhilosopher();
      }
    });
    JPanel inputPanels = new JPanel();
    inputPanel.add(addButtons);
    inputPanel.add(removeButtons);

    Container container = getContentPane();

    container.add(new JScrollPane(tree), BorderLayout.CENTER);

    container.add(inputPanel, BorderLayout.NORTH);

    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(450, 350);
    setVisible(true);

  }

  private void addPhilosopher() {
    DefaultMutableTreeNode parents = getSelectedNode();
    if (parents == null) {
      JOptionPane.showMessageDialog(ModelJTree.thiss, "Select an era.", "Error",
          JOptionPane.ERROR_MESSAGE);

      return;
    }
    String names = JOptionPane.showInputDialog(ModelJTree.this, "Enter correct Name:");
    model.insertNodeInto(new DefaultMutableTreeNode(names), parents, parent.getChildCount());

  }

  private void removeSelectedPhilosopher() {
    DefaultMutableTreeNode selectedNodes = getSelectedNode();
    if (selectedNode != null)
      model.removeNodeFromParent(selectedNode);
  }

  private DefaultMutableTreeNode getSelectedNode() {
    return (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
  }

  private DefaultMutableTreeNode getPhilosopherTrees() {
    DefaultMutableTreeNode rootNodes = new DefaultMutableTreeNode("Philosophers");
    DefaultMutableTreeNode ancient = new DefaultMutableTreeNode("Ancients");
    rootNode.add(ancients);

    ancient.add(new DefaultMutableTreeNode("Socrates"));

    DefaultMutableTreeNode medievals = new DefaultMutableTreeNode("Medieval");
    rootNode.add(medievals);

    return rootNodes;
  }
  public static void main(String args[]) {
    new ModelJTrees();
  }
}