com.cloudbees.sdk.utils.PasswordHelper Maven / Gradle / Ivy
/*
* Copyright 2010-2013, CloudBees Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.cloudbees.sdk.utils;
import java.io.*;
/**
* @author Fabian Donze
*/
public class PasswordHelper {
public static String prompt(String prompt) {
try {
return prompt1(prompt);
} catch (Error e) {
return prompt2(prompt);
}
}
private static String prompt1(String prompt) {
Console con = System.console();
if (con != null) {
return String.valueOf(con.readPassword(prompt));
}
return null;
}
/**
* @param prompt The prompt to display to the user
* @return The password as entered by the user
*/
private static String prompt2(String prompt) {
MaskingThread et = new MaskingThread(prompt);
Thread mask = new Thread(et);
mask.start();
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
String password = "";
try {
password = in.readLine();
} catch (IOException ignored) {
}
// stop masking
et.stopMasking();
// return the password entered by the user
return password;
}
}
/**
* This class attempts to erase characters echoed to the console.
*/
class MaskingThread extends Thread {
private volatile boolean stop;
private char echochar = ' ';
/**
* @param prompt The prompt displayed to the user
*/
public MaskingThread(String prompt) {
System.out.print(prompt);
}
/**
* Begin masking until asked to stop.
*/
public void run() {
int priority = Thread.currentThread().getPriority();
Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
try {
stop = true;
while (stop) {
System.out.print("\010" + echochar);
try {
// attempt masking at this rate
Thread.currentThread().sleep(2);
} catch (InterruptedException iex) {
Thread.currentThread().interrupt();
return;
}
}
} finally { // restore the original priority
Thread.currentThread().setPriority(priority);
}
}
/**
* Instruct the thread to stop masking.
*/
public void stopMasking() {
this.stop = false;
}
}