需求：当用户名密码输入正确文本框可编辑

 1 package unit13;
 2 
 3 import java.awt.Color;
 4 import java.awt.event.ActionEvent;
 5 import java.awt.event.ActionListener;
 6 
 7 import javax.swing.JFrame;
 8 import javax.swing.JLabel;
 9 import javax.swing.JPasswordField;
10 import javax.swing.JScrollPane;
11 import javax.swing.JTextArea;
12 import javax.swing.JTextField;
13 
14 public class app4 extends JFrame implements ActionListener {
15     private JLabel [] jArray={
16             new JLabel ("用户名:"),
17             new JLabel ("密码:")
18             };
19     
20     private JTextField jName=new JTextField();
21     private JPasswordField jPassword=new JPasswordField();
22      
23     private JTextArea jText=new JTextArea("我现在不可编辑",10,80);
24     private JScrollPane jsp=new JScrollPane(jText);
25     
26     public app4(){
27         this.setLayout(null);
28         jArray[0].setBounds(20,10,50,25);
29         jArray[1].setBounds(20,30,50,15);
30         
31         jName.setBounds(70,10,170,25);
32         jPassword.setBounds(70,35,170,25);
33         jsp.setBounds(20,70,220,100);
34         jText.setEnabled(false);
35         this.add(jArray[0]);
36         this.add(jArray[1]);
37         this.add(jName);
38         this.add(jPassword);
39         this.add(jsp);
40         jText.setDisabledTextColor(Color.red);
41         jName.addActionListener(this);
42         jPassword.addActionListener(this);
43         
44         this.setBounds(200,200,500,300);
45     }
46     
47     
48     
49     
50     
51     
52     public static void main(String[] args) {
53         // TODO 自动生成的方法存根
54      
55         app4 frm=new app4();
56         frm.setVisible(true);
57     }
58 
59     @Override
60     public void actionPerformed(ActionEvent e) {
61         // TODO 自动生成的方法存根
62         if(jName.getText().equals("abc")&&String.valueOf(jPassword.getPassword()).equals("123"))
63         {
64             jText.setEnabled(true);
65             jText.setText("恭喜你！！\n现在可以编辑了");
66             jText.setLineWrap(true);
67         }
68         
69         
70     }
71 
72 }