[GROOVY-2763] derived class can not inherit its parent method

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Won't Fix
• Affects Version/s: 1.5.5
• Fix Version/s: 1.5.6
• Environment: jdk1.6u6
• Assignee: Jochen Theodorou
• Reporter: Daniel Sun
• Created: 18/Apr/08 09:53
• Updated: 22/Apr/08 06:30
• Resolved: 21/Apr/08 13:59

Description

The following code can not be executed in Groovy Console, which complains:

Exception thrown: java.lang.NullPointerException: Cannot invoke method add() on null object

java.lang.NullPointerException: Cannot invoke method add() on null object
	at Demo.<init>(Script7:82)

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Toolkit;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Demo extends JFrame{

    Container contentPane;
    ImageIcon img = new ImageIcon("002.jpg");
   
    JPanel paneTop = new JPanel();
    JPanel paneMid = new JPanel();
    JPanel paneBut = new JPanel();
    JPanel paneAll = new JPanel();
   
    JLabel lblTop = new JLabel();
    JLabel lblName = new JLabel();
    JLabel lblPwd = new JLabel();
    JLabel lblApply = new JLabel();
    JLabel lblForget = new JLabel();
    JLabel lblModel = new JLabel();
    JLabel lblNull = new JLabel();
   
    JTextField txtName = new JTextField(15);
    JPasswordField txtPwd = new JPasswordField(15);
   
    JComboBox cmb = new JComboBox();
   
    JCheckBox chk = new JCheckBox();
   
    JButton btnKill = new JButton("查杀木马");
    JButton btnSet = new JButton("设置");
    JButton btnLogin = new JButton("登录");
   
   
   
    public Demo(){
        lblTop.setIcon(img);
        paneTop.add(lblTop);
       
        lblName.setText("QQ帐号:");
        lblApply.setText("申请帐号   ");
        lblPwd.setText("QQ密码:");
        lblForget.setText("忘记密码?");
        lblModel.setText("状态:");
       
        String[] s1 = ["隐身","在线","忙碌"] as String[];
        cmb.addItem(s1[0]);
        cmb.addItem(s1[1]);
        cmb.addItem(s1[2]);
       
        chk.setText("自动登录");
       
        paneMid.add(lblName);
        paneMid.add(txtName);
        paneMid.add(lblApply);
       
        paneMid.add(lblPwd);
        paneMid.add(txtPwd);
        paneMid.add(lblForget);
       
        paneMid.add(lblModel);
        paneMid.add(cmb);
        paneMid.add(chk);
       
        paneBut.add(btnKill);
        paneBut.add(btnSet);
        paneBut.add(btnLogin);
       
       contentPane = this.getContentPane();
       
       contentPane.add(paneTop,BorderLayout.NORTH);
       contentPane.add(paneMid,BorderLayout.CENTER);
       contentPane.add(paneBut,BorderLayout.SOUTH);
       
       
       
        setTitle("欢迎使用QQ");
        setSize(330,240);
        Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
        setLocation((screen.width - getSize().width)/2,(screen.height - getSize().height)/2 );
        setVisible(true);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       
    }
   
    public static void main(String[] args){
        Demo d = new Demo();
    }
   
}

After I commented the codes about contentPane variable, the code can not be executed too, the error message suggest us that the inheritance in Groovy does not work:

Exception thrown: groovy.lang.MissingMethodException: No signature of method: Demo.setLocation() is applicable for argument types: (java.lang.Double, java.lang.Double) values: {475.0, 280.0}

groovy.lang.MissingMethodException: No signature of method: Demo.setLocation() is applicable for argument types: (java.lang.Double, java.lang.Double) values: {475.0, 280.0}
	at Demo.invokeMethod(Script8)
	at Demo.<init>(Script8:91)

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Toolkit;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Demo extends JFrame{

    Container contentPane;
    ImageIcon img = new ImageIcon("002.jpg");
   
    JPanel paneTop = new JPanel();
    JPanel paneMid = new JPanel();
    JPanel paneBut = new JPanel();
    JPanel paneAll = new JPanel();
   
    JLabel lblTop = new JLabel();
    JLabel lblName = new JLabel();
    JLabel lblPwd = new JLabel();
    JLabel lblApply = new JLabel();
    JLabel lblForget = new JLabel();
    JLabel lblModel = new JLabel();
    JLabel lblNull = new JLabel();
   
    JTextField txtName = new JTextField(15);
    JPasswordField txtPwd = new JPasswordField(15);
   
    JComboBox cmb = new JComboBox();
   
    JCheckBox chk = new JCheckBox();
   
    JButton btnKill = new JButton("查杀木马");
    JButton btnSet = new JButton("设置");
    JButton btnLogin = new JButton("登录");
   
   
   
    public Demo(){
        lblTop.setIcon(img);
        paneTop.add(lblTop);
       
        lblName.setText("QQ帐号:");
        lblApply.setText("申请帐号   ");
        lblPwd.setText("QQ密码:");
        lblForget.setText("忘记密码?");
        lblModel.setText("状态:");
       
        String[] s1 = ["隐身","在线","忙碌"] as String[];
        cmb.addItem(s1[0]);
        cmb.addItem(s1[1]);
        cmb.addItem(s1[2]);
       
        chk.setText("自动登录");
       
        paneMid.add(lblName);
        paneMid.add(txtName);
        paneMid.add(lblApply);
       
        paneMid.add(lblPwd);
        paneMid.add(txtPwd);
        paneMid.add(lblForget);
       
        paneMid.add(lblModel);
        paneMid.add(cmb);
        paneMid.add(chk);
       
        paneBut.add(btnKill);
        paneBut.add(btnSet);
        paneBut.add(btnLogin);
       
      // contentPane = this.getContentPane();
       
       //contentPane.add(paneTop,BorderLayout.NORTH);
      // contentPane.add(paneMid,BorderLayout.CENTER);
      // contentPane.add(paneBut,BorderLayout.SOUTH);
       
       
       
        setTitle("欢迎使用QQ");
        setSize(330,240);
        Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
        setLocation((screen.width - getSize().width)/2,(screen.height - getSize().height)/2 );
        setVisible(true);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       
    }
   
    public static void main(String[] args){
        Demo d = new Demo();
    }
   
}