In this section, you will learn to create a horizontal tree in java.

Adding Horizontal lines to Group Nodes

     

Introduction

In this section, you will learn  to create a horizontal tree in java.

Description of the Program:

This program creates a JTree that contains a root and the nodes.This program implements a class (JTreeHorizontal). Here the init() method creates  root and the child nodes through DefaultMutableTreeNode method. These objects are added in the JTree and the putClintProperty() method displays them horizontally in a  JTree on the frame. 

putclientProperty(Object key, Object val):  The clientProperty dictionary is not intended to support large scale extensions to Jcomponent nor should it  be considered an alternative to subclassing when designing a new component. It takes following type values:

    key: This is the client property key.
  val: This is the client property value.

Here is the code of this program:

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

public class JTreeHorizontal extends JFrame{   JTree tree; 
  public JTreeHorizontal(){   super("JTreeHorizontal Frame"); 
  setSize(300, 300);   setDefaultCloseOperation(EXIT_ON_CLOSE);   }

  public void init(){ 
  DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); 
  DefaultMutableTreeNode book = new DefaultMutableTreeNode("Book"); 
  DefaultMutableTreeNode javabook = new DefaultMutableTreeNode("Java Book");  
  DefaultMutableTreeNode jspbook = new DefaultMutableTreeNode("JSP Book");  
  DefaultMutableTreeNode phpbook = new DefaultMutableTreeNode("PHP Book");  
  DefaultMutableTreeNode structbook = new DefaultMutableTreeNode("STRUCT Book");
  DefaultMutableTreeNode contry = new DefaultMutableTreeNode("CONTRY"); 
  DefaultMutableTreeNode india = new DefaultMutableTreeNode("INDIA"); 
  DefaultMutableTreeNode usa = new DefaultMutableTreeNode("USA"); 
  DefaultTreeModel treeModel = new DefaultTreeModel(root); 
  tree = new JTree(treeModel); 
  tree.putClientProperty("JTree.lineStyle", "Horizontal"); 
  treeModel.insertNodeInto(book,root, 0); 
  treeModel.insertNodeInto(contry,root, 0);   book.add(javabook); 
  book.add(jspbook);   book.add(phpbook);   book.add(structbook); 
  contry.add(india);   contry.add(usa); 
  getContentPane().add(tree, BorderLayout.CENTER);   }

  public static void main(String args[]){
  JTreeHorizontal jh = new JTreeHorizontal();   
    jh.init(); 
  jh.setVisible(true);   } } 

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