NullPointerException with JTree.setModel()
Hi,
I am getting a Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException with the following code:
public class JTreeTest extends javax.swing.JFrame {
public JTreeTest() {
String Test = "Top Node";
DefaultMutableTreeNode TopNode = new DefaultMutableTreeNode(Test, true);
DefaultTreeModel TheTree = new DefaultTreeModel(TopNode);
// This is the instruction causing the issue...
jTree1.setModel(TheTree);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
JTreeTest TheTest = new JTreeTest();
TheTest.setVisible(true);
}
});
}
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTree1 = new javax.swing.JTree();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jScrollPane1.setBorder(null);
jTree1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.LOWERED));
jTree1.setAutoscrolls(true);
jScrollPane1.setViewportView(jTree1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 192, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane1)
.addContainerGap())
);
pack();
}
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTree jTree1;
}
I can't figure out what I am doing wrong... Any one has ideas? Thanks !!!
