How to allow only a single tree node to be selected in a JTree with Java?

Set the selection mode to SINGLE_TREE_SELECTION, if you want only a single tree node to be selected −

tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);

The following is an example to allow only a single tree node to be selected in a JTree −

Example

package my;
import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeSelectionModel;
public class SwingDemo {
   public static void main(String[] args) throws Exception {
      JFrame frame = new JFrame("Demo");
      DefaultMutableTreeNode node = new DefaultMutableTreeNode("Products");
      DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("Clothing");
      DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("Electronics");
      DefaultMutableTreeNode node3 = new DefaultMutableTreeNode("Home Decor");
      DefaultMutableTreeNode node4 = new DefaultMutableTreeNode("Furniture");
      node.add(node1);
      node.add(node2);
      node.add(node3);
      node.add(node4);
      DefaultMutableTreeNode one = new DefaultMutableTreeNode("Shirt");
      DefaultMutableTreeNode two = new DefaultMutableTreeNode("Trousers");
      DefaultMutableTreeNode three = new DefaultMutableTreeNode("Jeans");
      DefaultMutableTreeNode four = new DefaultMutableTreeNode("Mobiles");
      DefaultMutableTreeNode five = new DefaultMutableTreeNode("Camera");
      DefaultMutableTreeNode six = new DefaultMutableTreeNode("Tablet");
      DefaultMutableTreeNode seven = new DefaultMutableTreeNode("Paintings");
      DefaultMutableTreeNode eight = new DefaultMutableTreeNode("Showpieces");
      DefaultMutableTreeNode nine = new DefaultMutableTreeNode("Wardrobes");
      DefaultMutableTreeNode ten = new DefaultMutableTreeNode("Bean Bags");
      node1.add(one);
      node1.add(two);
      node1.add(three);
      node2.add(four);
      node2.add(five);
      node2.add(six);
      node3.add(seven);
      node3.add(eight);
      node4.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");
      tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
      tree.setRowHeight(25);
      frame.add(tree);
      frame.setSize(600,450);
      frame.setVisible(true);
   }
}

This will produce the following output. You can only select a single node. Using CTRL to select multiple nodes won’t work −

Output