ThreadBuilder.java

/*
 * ThreadBuilder.java February 2009
 *
 * Copyright (C) 2009, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed 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.simpleframework.util.thread;

/**
 * The <code>ThreadBuilders</code> object is used to build threads and prefix
 * the thread with a type name. Prefixing the threads with the type that it
 * represents allows the purpose of the thread to be determined and also
 * provides better debug information.
 * 
 * @author Niall Gallagher
 */
class ThreadBuilder {

    /**
     * This is used to create a thread from the provided runnable. The thread
     * created will contain a unique name which is prefixed with the type of
     * task it has been created to execute. This provides some detail as to what
     * the thread should be doing.
     * 
     * @param task
     *            this is the task that the thread is to execute
     * 
     * @return this returns a thread that will executed the given task
     */
    public static Thread build(Runnable task) {
        Thread thread = getThread(task);
        String name = getName(task, thread);

        if (!thread.isAlive()) {
            thread.setName(name);
        }
        return thread;
    }

    /**
     * This is used to create a thread from the provided runnable. The thread
     * created will contain a unique name which is prefixed with the type of
     * task it has been created to execute. This provides some detail as to what
     * the thread should be doing.
     * 
     * @param task
     *            this is the task that the thread is to execute
     * @param type
     *            this is the type of object the thread is to execute
     * 
     * @return this returns a thread that will executed the given task
     */
    public static Thread build(Runnable task, Class type) {
        Thread thread = getThread(task);
        String name = getName(type, thread);

        if (!thread.isAlive()) {
            thread.setName(name);
        }
        return thread;
    }

    /**
     * This will create a thread name that is unique. The thread name is a
     * combination of the original thread name with a prefix of the type of the
     * object that will be running within it.
     * 
     * @param task
     *            this is the task to be run within the thread
     * @param thread
     *            this is the thread containing the original name
     * 
     * @return this will return the new name of the thread
     */
    private static String getName(Runnable task, Thread thread) {
        Class type = task.getClass();

        return getName(type, thread);
    }

    /**
     * This will create a thread name that is unique. The thread name is a
     * combination of the original thread name with a prefix of the type of the
     * object that will be running within it.
     * 
     * @param type
     *            this is the type of object to be executed
     * @param thread
     *            this is the thread containing the original name
     * 
     * @return this will return the new name of the thread
     */
    private static String getName(Class type, Thread thread) {
        String prefix = type.getSimpleName();
        String name = thread.getName();

        return String.format("%s: %s", prefix, name);
    }

    /**
     * This is used to create the thread that will be used to execute the
     * provided task. The created thread will be renamed after it has been
     * created and before it has been started.
     * 
     * @param task
     *            this is the task that is to be executed
     * 
     * @return this returns a thread to execute the given task
     */
    private static Thread getThread(Runnable task) {
        return new Thread(task);
    }
}