org.remus.cmdlinehero.base.Executor.java Source code

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Here is the source code for org.remus.cmdlinehero.base.Executor.java

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/**
 * Copyright (c) 2014 Tom Seidel, Remus Software.
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of 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.remus.cmdlinehero.base;

import java.text.MessageFormat;
import java.util.Date;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.log4j.Logger;
import org.springframework.stereotype.Service;

/**
 * An executor of {@link ExecutionInstruction}s. Has also the ability to handle
 * {@link TaskListener} and their respective Events
 * 
 * @author Tom Seidel - tom.seidel@remus-software.org
 * 
 */
@Service
public class Executor {

    private final ExecutorService pool;

    private final Set<TaskListener> listeners = new CopyOnWriteArraySet<TaskListener>();

    private final Logger LOGGER = Logger.getLogger(Executor.class);

    public Executor() {
        pool = Executors.newFixedThreadPool(10);
    }

    public void schedule(final ExecutionInstruction job) {
        final String string = UUID.randomUUID().toString();
        job.setRuntimeId(string);
        job.setExecutor(this);
        notifySchedule(job);
        pool.submit(job);
    }

    public void shutdown() {
        pool.shutdown();
    }

    final void notifySchedule(final ExecutionInstruction instruction) {
        LOGGER.info(MessageFormat.format("Scheduled job {0}", instruction.getClass().getSimpleName()));
        for (final TaskListener listener : listeners) {
            try {
                listener.taskScheduled(new TaskChangeEvent(instruction, new Date()));
            } catch (final Throwable t) {
                // do nothing
            }
        }
    }

    final void notifyStart(final ExecutionInstruction instruction) {
        for (final TaskListener listener : listeners) {
            try {
                listener.taskStarted(new TaskChangeEvent(instruction, new Date()));
            } catch (final Throwable t) {
                // do nothing
            }
        }
    }

    final void notifyFinish(final ExecutionInstruction instruction) {
        for (final TaskListener listener : listeners) {
            try {
                listener.taskFinished(new TaskChangeEvent(instruction, new Date()));
            } catch (final Throwable t) {
                // do nothing
            }
        }
    }

    public final void addListener(final TaskListener listener) {
        listeners.add(listener);
    }

    public final void removeListener(final TaskListener listener) {
        listeners.remove(listener);
    }

}