How to Hide when input password ?

Question

How to Hide input char when input password
     if (passwd.trim().equals("")) {
          System.out.print("What is your password: ");
          try     { while     (System.in.available() == 0) {
          passwd = new BufferedReader(new     InputStreamReader(System.in)).readLine();
          catch (IOException e) {passwd =     "<"     + e     + ">";}

Answer 1

Hi,
I've taken this from a article by Qusay H. Mahmoud .
This can help you.
-----File: PasswordApp.java-------
import java.io.*;
* @author Qusay H. Mahmoud
public class PasswordApp {
   public static void main(String argv[]) {
      PasswordField passfield = new PasswordField();
      String password = null;
      try {
         password = passfield.getPassword("Enter your password: ");
      } catch(IOException ioe) {
         ioe.printStackTrace();
      System.out.println("The password entered is: "+password);
}-----File: PasswordField.java-------
import java.io.*;
* @author Qusay H. Mahmoud
* This class attempts to erase characters echoed to the console.
class MaskingThread extends Thread {
   private boolean stop = false;
   private int index;
   private String prompt;
   *@param prompt The prompt displayed to the user
   public MaskingThread(String prompt) {
      this.prompt = prompt;
   * Begin masking until asked to stop.
   public void run() {
      while(!stop) {
         try {
            // attempt masking at this rate
            this.sleep(1);
         }catch (InterruptedException iex) {
            iex.printStackTrace();
         if (!stop) {
            System.out.print("\r" + prompt + " \r" + prompt);
         System.out.flush();
   * Instruct the thread to stop masking.
   public void stopMasking() {
      this.stop = true;
* This class prompts the user for a password and attempts to mask input with ""
public class PasswordField {
   *@param prompt The prompt to display to the user.
   *@return The password as entered by the user.
   String getPassword(String prompt) throws IOException {
      // password holder
      String password = "";
      MaskingThread maskingthread = new MaskingThread(prompt);
      Thread thread = new Thread(maskingthread);
      thread.start();
      // block until enter is pressed
      while (true) {
         char c = (char)System.in.read();
         // assume enter pressed, stop masking
         maskingthread.stopMasking();
         if (c == '\r') {
            c = (char)System.in.read();
            if (c == '\n') {
               break;
            } else {
               continue;
         } else if (c == '\n') {
            break;
         } else {
            // store the password
            password += c;
      return password;
}-Manish.