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.qpid.disttest.client; import java.util.concurrent.Executor; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.ThreadFactory; import org.apache.commons.lang.builder.ToStringBuilder; import org.apache.commons.lang.builder.ToStringStyle; import org.apache.qpid.disttest.message.ParticipantResult; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class ParticipantExecutor { private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantExecutor.class); private static final ExecutorService SHARED_UNBOUNDED_THREAD_POOL = Executors .newCachedThreadPool(new DaemonThreadFactory()); private Executor _executor = SHARED_UNBOUNDED_THREAD_POOL; private Client _client; private final Participant _participant; private final ParticipantResultFactory _factory; public ParticipantExecutor(Participant participant) { _participant = participant; _factory = new ParticipantResultFactory(); } /** * Schedules the test participant to be run in a background thread. */ public void start(Client client) { _client = client; LOGGER.debug("Starting test participant in background thread: " + this); _executor.execute(new ParticipantRunnable()); } public String getParticipantName() { return _participant.getName(); } void setExecutor(Executor executor) { _executor = executor; } private class ParticipantRunnable implements Runnable { @Override public final void run() { Thread currentThread = Thread.currentThread(); final String initialThreadName = currentThread.getName(); currentThread.setName(initialThreadName + "-" + getParticipantName()); try { runParticipantAndSendResults(); } finally { currentThread.setName(initialThreadName); } } private void runParticipantAndSendResults() { ParticipantResult result = null; try { if (LOGGER.isDebugEnabled()) { LOGGER.debug("About to run participant " + _participant); } result = _participant.doIt(_client.getClientName()); } catch (Throwable t) { String errorMessage = "Unhandled error: " + t.getMessage(); LOGGER.error(errorMessage, t); result = _factory.createForError(_participant.getName(), _client.getClientName(), errorMessage); } finally { try { _participant.releaseResources(); } catch (Exception e) { LOGGER.error("Participant " + _participant + " unable to release resources", e); } _client.sendResults(result); } } } private static final class DaemonThreadFactory implements ThreadFactory { @Override public Thread newThread(Runnable r) { Thread thread = new Thread(r); thread.setDaemon(true); return thread; } } @Override public String toString() { return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE) .append("participantName", getParticipantName()).append("client", _client).toString(); } }