Java tutorial
/******************************************************************************* * (c) Copyright 2016 Hewlett-Packard Development Company, L.P. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Apache License v2.0 which accompany this distribution. * * The Apache License is available at * http://www.apache.org/licenses/LICENSE-2.0 * *******************************************************************************/ package io.cloudslang.lang.cli.services; import org.apache.commons.lang3.builder.EqualsBuilder; import org.apache.commons.lang3.builder.HashCodeBuilder; import org.fusesource.jansi.Ansi; import org.fusesource.jansi.AnsiConsole; import org.springframework.beans.factory.DisposableBean; import org.springframework.stereotype.Service; import javax.annotation.PostConstruct; import java.util.concurrent.ExecutionException; import java.util.concurrent.Future; import java.util.concurrent.RejectedExecutionException; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeoutException; import static java.util.concurrent.Executors.newFixedThreadPool; import static org.fusesource.jansi.Ansi.ansi; @Service public class ConsolePrinterImpl implements ConsolePrinter, DisposableBean { private ThreadPoolExecutor singleThreadExecutor; private Future<?> lastTask; @PostConstruct public void initialize() { singleThreadExecutor = (ThreadPoolExecutor) newFixedThreadPool(1); // one thread only } @Override public void destroy() throws Exception { singleThreadExecutor.shutdown(); singleThreadExecutor = null; } @Override public synchronized void waitForAllPrintTasksToFinish() { try { if (lastTask != null) { lastTask.get(1, TimeUnit.MINUTES); } } catch (InterruptedException | ExecutionException | TimeoutException ignore) { } } @Override public synchronized Future<?> printWithColor(final Ansi.Color color, final String message) { try { lastTask = singleThreadExecutor.submit(new ConsolePrinterRunnable(color, message)); return lastTask; } catch (RejectedExecutionException ignore) { } return null; } static class ConsolePrinterRunnable implements Runnable { private final Ansi.Color color; private final String message; ConsolePrinterRunnable(Ansi.Color color, String message) { this.color = color; this.message = message; } @Override public void run() { try { AnsiConsole.out().print(ansi().fg(color).a(message).newline()); AnsiConsole.out().print(ansi().fg(Ansi.Color.WHITE)); } catch (Exception ignore) { // so that this thread does not die } } @Override public boolean equals(Object object) { if (object == null) { return false; } if (object == this) { return true; } if (object.getClass() != getClass()) { return false; } ConsolePrinterRunnable consolePrinterRunnable = (ConsolePrinterRunnable) object; return new EqualsBuilder().append(this.color, consolePrinterRunnable.color) .append(this.message, consolePrinterRunnable.message).isEquals(); } @Override public int hashCode() { return new HashCodeBuilder().append(color).append(message).toHashCode(); } } }