Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with this * work for additional information regarding copyright ownership. The ASF * licenses this file to You 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 org.apache.sling.testing.serversetup.jarexec; import java.util.Timer; import java.util.TimerTask; import org.apache.commons.exec.ProcessDestroyer; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** Simple ProcessDestroyer for a single process, meant to be used * with our JarExecutor. */ class ShutdownHookSingleProcessDestroyer implements ProcessDestroyer, Runnable { private final Logger log = LoggerFactory.getLogger(getClass()); private Thread shutdownHookThread; private Process process; private final int timeoutSeconds; private final String processInfo; private boolean waitOnShutdown = false; public ShutdownHookSingleProcessDestroyer(String processInfo, int timeoutSeconds) { this.processInfo = processInfo; this.timeoutSeconds = timeoutSeconds; } public boolean getWaitOnShutdown() { return waitOnShutdown; } public void setWaitOnShutdown(boolean waitOnShutdown) { this.waitOnShutdown = waitOnShutdown; } public synchronized boolean add(Process p) { if (process != null) { throw new IllegalStateException("Process already set: " + process); } if (shutdownHookThread == null) { shutdownHookThread = new Thread(this, getClass().getSimpleName()); Runtime.getRuntime().addShutdownHook(shutdownHookThread); } process = p; return true; } public synchronized boolean remove(Process p) { p = null; return true; } public int size() { return 1; } public void run() { destroyProcess(waitOnShutdown); } public void destroyProcess(boolean waitForIt) { Process toDestroy = null; synchronized (this) { toDestroy = process; process = null; } if (toDestroy == null) { return; } toDestroy.destroy(); if (waitForIt) { log.info("Waiting for destroyed process {} to exit (timeout={} seconds)", processInfo, timeoutSeconds); final Thread mainThread = Thread.currentThread(); final Timer t = new Timer(true); final TimerTask task = new TimerTask() { @Override public void run() { mainThread.interrupt(); } }; t.schedule(task, timeoutSeconds * 1000L); try { toDestroy.waitFor(); try { final int exit = toDestroy.exitValue(); log.info("Process {} ended with exit code {}", processInfo, exit); } catch (IllegalStateException ise) { log.error("Failed to destroy process " + processInfo); } } catch (InterruptedException e) { log.error("Timeout waiting for process " + processInfo + " to exit"); } finally { t.cancel(); } } } }