How to Use Password Fields in Java?

[pushpendra]

I have completed the basic programs of the Java. I had started doing Java from last month. But still I don't know how to use the Password Fields in Java..?? I have tried to do lot of different things, but i am not getting the desired results. So I thought that posting to you guys might help me. Please tell me the solution for my problem. Any coding related to the topic would be grateful. Hoping that I will get help sooner.!!

[opaper]

Before moving to the codes, I think that you should know the basic things about the password fields. Once you are clear with the concepts, then you can go towards the coding side. Otherwise, without the concept you will not understand the coding. When the steps to use, why to use..?? will make you more confuse will writing the code. So, here is the information. The JPasswordField class, a subclass of JTextField, provides specialized text fields for password entry. A password field does not show the characters that the user types. Instead, the field displays a character different from the one typed, such as an asterisk '*'.

[Reegan]

You should also know that a password field stores its value as an array of characters, rather than as a string. In Java, login screens and login dialog boxes use password masking. Password masking is a technique to either hide the password as it is being typed or displaying a character (such as an asterisk '*') instead of the characters that users type. You can observe such things when you enter the password into your computer. The only thing you can see are the asterisk '*. In this way your password is protected.

[Praetor]

If you wish to provide a graphical login dialog box for your application, you can use the AWT's TextField class, which is a text component that allows the editing of a single line of text. To mask the password field, use the setEchoChar method. You can use the following example for hiding the characters from the other users :

TextField password = new TextField(6);
password.setEchoChar('*');

In the above example, the number 6 specifies the width of the text field based on the average character width for the font in use.

[CodGuru]

I have provided you with a coding that can help you for using the password fields in Java :

public class PasswordField {

   public static String readPassword (String prompt) {
      EraserThread t = new EraserThread(prompt);
      Thread mask = new Thread(t);
      mask.start();

      BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
      String password = "";

      try {
         password = in.readLine();
      } catch (IOException ioe) {
        ioe.printStackTrace();
      }
      t.stopMasking();
      return password;
   }
}

[Allan.d]

You can also give the password after implementing of the action listener's actionPerformed method, just like I have done in the following example :

public void actionPerformed(ActionEvent ae) {
    String cmd = ae.getActionCommand();

    if (OK.equals(cmd)) { 
        char[] input = passwordField.getPassword();
        if (isPasswordCorrect(input)) {
            JOptionPane.showMessageDialog(controllingFrame,
                "Thank You!!");
        } else {
            JOptionPane.showMessageDialog(controllingFrame,
                "Access Denied. Try again.",
                "Error Message",
                JOptionPane.ERROR_MESSAGE);
        }

        Arrays.fill(input, '0');

        passwordField.selectAll();
        resetFocus();
    } else ...
}