Proxy Authentication Compilation Error

Question

Hi Java Expert,
I am sampling the following code from http://www.javaworld.com/javaworld/javatips/jw-javatip46.html in an effort to authenticate the proxy that is situated behind the firewall:
C:\Documents and Settings\htran\DnldURL\src\proxy\URLPassword.java
1 package proxy;
2
3 import java.io.*;
4 import java.net.*;
5 import java.awt.*;
6 import java.awt.event.*;
7
8 public class URLPassword extends Frame {
9
10     private TextField tf = new TextField();
11     private TextArea ta = new TextArea();
12
13     public URLPassword() {
14         super("URL Password");
15         // Install Authenticator
16         Authenticator.setDefault(new MyAuthenticator());
17         // Setup screen
18         add(tf, BorderLayout.NORTH);
19         ta.setEditable(false);
20         add(ta, BorderLayout.CENTER);
21         tf.addActionListener(new ActionListener() {
22
23             public void actionPerformed(ActionEvent e) {
24                 String s = tf.getText();
25                 if (s.length() != 0) {
26                     ta.setText(fetchURL(s));
27                 }
28             }
29         });
30         addWindowListener(new WindowAdapter() {
31
32             public void windowClosing(WindowEvent e) {
33                 dispose();
34                 System.exit(0);
35             }
36         });
37     }
38
39     private String fetchURL(String urlString) {
40         StringWriter sw = new StringWriter();
41         PrintWriter pw = new PrintWriter(sw);
42         try {
43             URL url = new URL(urlString);
44             InputStream content = (InputStream) url.getContent();
45             BufferedReader in =
46                     new BufferedReader(new InputStreamReader(content));
47             String line;
48             while ((line = in.readLine()) != null) {
49                 pw.println(line);
50             }
51         } catch (MalformedURLException e) {
52             pw.println("Invalid URL");
53         } catch (IOException e) {
54             pw.println("Error reading URL");
55         }
56         return sw.toString();
57     }
58
59     public static void main(String args[]) {
60         Frame f = new URLPassword();
61         f.setSize(300, 300);
62         f.setVisible(true);
63     }
64
65     class MyAuthenticator extends Authenticator {
66         protected PasswordAuthentication getPasswordAuthentication() {
67             final Dialog jd = new Dialog(URLPassword.this, "Enter password", true);
68             jd.setLayout(new GridLayout(0, 1));
69             Label jl = new Label(getRequestingPrompt());
70             jd.add(jl);
71             TextField username = new TextField();
72             username.setBackground(Color.lightGray);
73             jd.add(username);
74             TextField password = new TextField();
75             password.setEchoChar('*');
76             password.setBackground(Color.lightGray);
77             jd.add(password);
78             Button jb = new Button("OK");
79             jd.add(jb);
80             jb.addActionListener(new ActionListener() {
81
82                 public void actionPerformed(ActionEvent e) {
83                     jd.dispose();
84                 }
85             });
86             jd.pack();
87             jd.setVisible(true);
88             return new PasswordAuthentication(username.getText(), password.getText());
89         }
90     }
91 }However, I could not compile it due to the following error from the last line:
Compiling 1 source file to C:\Documents and Settings\htran\DnldURL\build\classes
C:\Documents and Settings\htran\DnldURL\src\proxy\URLPassword.java:88: cannot find symbol
symbol  : constructor PasswordAuthentication(java.lang.String,java.lang.String)
location: class java.net.PasswordAuthentication
return new PasswordAuthentication(username.getText(), password.getText());
*1 error*
BUILD FAILED (total time: 1 second)
Netbeans also suggested to Add @Overwrite Annotation to getPasswordAuthentication() method on line 66. Any reason why?
This appears to be using nested class that I am not familiar with.
I am running Netbeans 6.0, jdk1.6.0_03 on Windows XP platform.
Thanks a lot,
Jack

Answer 1

Hi,
Your suggestion has resolved the compilation error.
Thanks for your help,
Jack