package com.idealisan.cores;import java.util.HashMap;
import java.util.Scanner;public class ConsoleListener {HashMap<String, Action> answers = new HashMap<String, ConsoleListener.Action>();Scanner scanner;Action defaultAction;/*** Add an action for a message.* @param message A string trimed. Ignore case. It has no inner space sequence of two spaces or more.* Example:"close connection"* @param action The method action.act() will be called when scanner get the message.*/public void addAction(String message, Action action) {answers.put(message.toLowerCase(), action);}/*** * @param scanner Usually new Scanner(System.in). * Will not be closed after listening.* @param defaultAction The defaultAction.act() method will be called if an action is not added for a message.*/public ConsoleListener(Scanner scanner, Action defaultAction) {this.scanner = scanner;this.defaultAction = defaultAction;if (scanner == null || defaultAction == null) {throw new NullPointerException("null params for ConsoleListener");}}public void removeAction(String message, Action action) {answers.remove(message, action);}public Action replaceAction(String message, Action action) {return answers.replace(message, action);}public void listenInNewThread() {Thread t = new Thread() {public void run() {listen();}};t.start();}/*** Use listenInNewThread() instead.* Listen to console input in current thread. It blocks the thread.*/public void listen() {while (true) {String line = scanner.nextLine();String msg = line.replaceAll("[\\s]+", " ");msg = msg.trim().toLowerCase();Action action = answers.get(msg);if (action == null) {action = defaultAction;}action.act(line);}}public static interface Action {public void act(String msg);}
}

package com.idealisan.test;import java.util.Scanner;import com.idealisan.cores.ConsoleListener;/*** Hello world!**/
public class App {public static void main(String[] args) {ConsoleListener cs = new ConsoleListener(new Scanner(System.in), new ConsoleListener.Action() {public void act(String msg) {System.out.println("Console: " + msg);}});cs.addAction("stop", new ConsoleListener.Action() {public void act(String msg) {System.out.println("Console: Bye");System.exit(0);}});cs.addAction("stop repeating", new ConsoleListener.Action() {public void act(String msg) {System.out.println("Console: ...");}});cs.listenInNewThread();while (true) {try {Thread.sleep(1);} catch (InterruptedException e) {// TODO Auto-generated catch block
                e.printStackTrace();}}}
}