Java AWT 编程 空指针异常 哪里出错了？

[cj2011933014]

RT
源代码：

package TEST;

import java.awt.*;
import java.awt.event.*;
import java.text.MessageFormat;

public class Start implements ActionListener{
	TextField user;
	TextField password;
    public Start(){
       Frame f = new Frame("登录界面");
       f.setLayout(new BorderLayout());
       Panel p1 = new Panel();
       p1.setLayout(new GridLayout(2,1));
       p1.add(new Label("用户名："));
       p1.add(new Label("密码："));
       Panel p2 = new Panel();
       p2.setLayout(new GridLayout(2,1));
       TextField user = new TextField();
       TextField password = new TextField(10);
       password.setEchoChar('*');
       user.addActionListener(this);
       password.addActionListener(this);
       p2.add(user);
       p2.add(password);
       Panel p3 = new Panel();
       p3.setLayout(new FlowLayout());
       Button submit = new Button("确定");
       Button reset = new Button("重置");
       submit.addActionListener(this);
       reset.addActionListener(this);
       p3.add(submit);
       p3.add(reset);
       f.add(p1,BorderLayout.WEST);
       f.add(p2,BorderLayout.CENTER);   
       f.add(p3,BorderLayout.SOUTH);
       f.add(new Label("请输入你的用户信息："),BorderLayout.NORTH);
       f.setVisible(true);
       f.setLocation(320,240);
       f.pack();
       f.addWindowListener(new FormAdapter());
    }
	public static void main(String[] args) {
		// TODO Auto-generated method stub
        Start st = new Start();
	}
    private class FormAdapter extends WindowAdapter{
    	public void windowClosing(WindowEvent e){
    		System.exit(0);
    	}
    }
	//@Override
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
		String str = e.getActionCommand();
		if(str.equals("确定")){
			System.out.println(str);
			System.out.println(user.getText());
			//System.out.println(password.getText());
		}else if(str.equals("重置")){
			System.out.println(str);
		}
	}
}

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at TEST.Start.actionPerformed(Start.java:58)
	at java.awt.Button.processActionEvent(Unknown Source)
	at java.awt.Button.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$000(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

[cj2011933014]

顶，求帮忙！

[twjob_51]

在实例化两个button后，添加下面两句。
submit.setActionCommand("确定");
reset.setActionCommand("重置");

[cj2011933014]

默认就是他们的Cpation吧，我加了还是出错！

[ITshashou]

System.out.println(user.getText());
这句报错
你的TextField user 没有实例

[ITshashou]

TextField user = new TextField();

改成 user = new TextField();
你上面已经申明了 不要再申明

[twjob_51]

把下面两句 TextField user = new TextField();
TextField password = new TextField(10);
修改为 user = new TextField();
password = new TextField(10);
你调用的是全局变量的user和这里的user不是一个对象

[cj2011933014]

谢谢LS and LSLS``