Java Program to get the count of child nodes of any node in JTree

Java 8Object Oriented ProgrammingProgramming

Use the getChildCount() method in Java to get the count of child nosed of any node i.e. even if it’s a root node or not.

Let’s say we want the count of child nodes for node 1, which is not a root node, therefore −

node1.getChildCount()

The following is an example to get the count of child nodes of any node −

Example

package my;
import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
public class SwingDemo {
   public static void main(String[] args) throws Exception {
      JFrame frame = new JFrame("Demo");
      DefaultMutableTreeNode node = new DefaultMutableTreeNode("Website");
      DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Videos");
      DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Tutorials");
      DefaultMutableTreeNode node3 = new DefaultMutableTreeNode("QA");
      DefaultMutableTreeNode node4 = new DefaultMutableTreeNode("Tools");
      node.add(node1);
      node.add(node2);
      node.add(node3);
      node.add(node4);
      DefaultMutableTreeNode one = new DefaultMutableTreeNode("PHP Videos");
      DefaultMutableTreeNode two = new DefaultMutableTreeNode("HTML5 Videos");
      DefaultMutableTreeNode three = new DefaultMutableTreeNode("Blockchain Videos");
      DefaultMutableTreeNode four = new DefaultMutableTreeNode("Java");
      DefaultMutableTreeNode five = new DefaultMutableTreeNode("DBMS");
      DefaultMutableTreeNode six = new DefaultMutableTreeNode("CSS");
      DefaultMutableTreeNode seven = new DefaultMutableTreeNode("MongoDB");
      DefaultMutableTreeNode eight = new DefaultMutableTreeNode("Python QA");
      DefaultMutableTreeNode nine = new DefaultMutableTreeNode("jQuery QA");
      DefaultMutableTreeNode ten = new DefaultMutableTreeNode("Photo Editing Tool");
      node1.add(one);
      node1.add(two);
      node1.add(three);
      node2.add(four);
      node2.add(five);
      node2.add(six);
      node2.add(seven);
      node3.add(eight);
      node3.add(nine);
      node4.add(ten);
      JTree tree = new JTree(node);
      for (int i = 0; i < tree.getRowCount(); i++) {
         tree.expandRow(i);
      }
      tree.putClientProperty("JTree.lineStyle", "Angled");
      System.out.println("Number of children of node1 (Videos) = " + node1.getChildCount());
      System.out.println("Number of children of node2 (Tutorials) = " + node2.getChildCount());
      System.out.println("Number of children of node3 (QA) = " + node3.getChildCount());
      System.out.println("Number of children of node4 (Tools) = " + node4.getChildCount());
      tree.setRowHeight(25);
      frame.add(tree);
      frame.setSize(600,450);
      frame.setVisible(true);
   }
}

The Console displays the count of each node −

Output

The JTree is as follows


raja
Published on 04-Jun-2019 11:40:25
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