simple GUI implementation problem

[Stevo27]

I have to research GUI components to provide an interface for a university OOP project. I am halfway through chapter 11 of the Deitel "Java how to Program" 6th edition and have tried to compile and run the code shown below but get 4 errors which appear to relate to the format method of String:

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;

public class TextFieldFrame extends JFrame
{
private JTextField textField1;
private JTextField textField2;
private JTextField textField3;
private JPasswordField passwordField;

public TextFieldFrame(){
super("Testing JTextField and JPasswordField");
setLayout(new FlowLayout());

textField1 = new JTextField(10);
add(textField1);

textField2 = new JTextField("Enter text here");
add(textField2);

textField3 = new JTextField("Uneditable text field", 21);
textField3.setEditable(false);
add(textField3);

passwordField = new JPasswordField("Hidden text");
add(passwordField);

TextFieldHandler handler = new TextFieldHandler();
textField1.addActionListener(handler);
textField2.addActionListener(handler);
textField3.addActionListener(handler);
passwordField.addActionListener(handler);
}

private class TextFieldHandler implements ActionListener{
public void actionPerformed(ActionEvent event){
String string = "";

if (event.getSource()==textField1)
string = String.format("textField1: %s", event.getActionCommand());
else if (event.getSource()==textField2)
string = String.format("textField2: %s", event.getActionCommand());
else if (event.getSource()==textField3)
string = String.format("textField3: %s", event.getActionCommand());
else if (event.getSource()==passwordField)
string = String.format("passwordField: %s", new String(passwordField.getPassword()));

JOptionPane.showMessageDialog(null, string);
}
}
}





import javax.swing.JFrame;
public class TextFieldTest
{
public static void main(String[] args)
{
TextFieldFrame textFieldFrame = new TextFieldFrame();
textFieldFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
textFieldFrame.setSize(325,100);
textFieldFrame.setVisible(true);
}
}




The errors are as follows:

---------- Compile ----------
TextFieldFrame.java:45: cannot resolve symbol
symbol : method format (java.lang.String,java.lang.String)
location: class java.lang.String
string = String.format("textField1: %s", event.getActionCommand());
^
TextFieldFrame.java:47: cannot resolve symbol
symbol : method format (java.lang.String,java.lang.String)
location: class java.lang.String
string = String.format("textField2: %s", event.getActionCommand());
^
TextFieldFrame.java:49: cannot resolve symbol
symbol : method format (java.lang.String,java.lang.String)
location: class java.lang.String
string = String.format("textField3: %s", event.getActionCommand());
^
TextFieldFrame.java:51: cannot resolve symbol
symbol : method format (java.lang.String,java.lang.String)
location: class java.lang.String
string = String.format("passwordField: %s", new String(passwordField.getPassword()));
^
4 errors

Output completed (0 sec consumed) - Normal Termination

Could anyone please tell me how to correct the code to get the application running properly?

Thanks.

[Stevo27]

Figured out the solution - I had the compile tool set to Java 1.4 rather than 1.5. Changed it and it works fine.
Thanks anyway.