Java并发模式

在公司做培训时用到，顺便在这里做个总结。
1.生产者消费者模式
        某个模块负责产生数据，这些数据由另一个模块来负责处理（此处的模块是广义的，可以是类、函数、线程、进程等）。产生数据的模块，就形象地称为生产者；而处理数据的模块，就称为消费者。在生产者与消费者之间在加个缓冲区，我们形象的称之为仓库，生产者负责往仓库了进商品，而消费者负责从仓库里拿商品，这就构成了生产者消费者模式。

/**
 * 
 * 类功能描述：数据对象
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-4-2 上午11:01:53
 */
public class MyData {
	
	private final long intData;
	
	public MyData(long d){
		intData = d;
	}
	
	@Override
	public String toString(){
		return " MyData:"+intData;
	}
}

import java.util.concurrent.BlockingQueue;

public abstract class AbstractPC implements Runnable {
	
	protected BlockingQueue<MyData> queue;
	
	protected volatile boolean isRunning = true;
	
	public void stop() {
		isRunning = false;
	}
}

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 
 * 类功能描述：生产者
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-4-2 上午11:02:13
 */
public class Producer extends AbstractPC{
	
	private static AtomicInteger count = new AtomicInteger(0);
	
	private static final int SLEEP_TIME = 3000;

	public Producer(BlockingQueue<MyData> queue) {
		this.queue = queue;
	}

	public void run() {
		System.out.println("Producer:"+Thread.currentThread().getName()+" start");
		try {
			while (isRunning) {
				Thread.sleep(SLEEP_TIME);
				MyData data = new MyData(count.incrementAndGet());
				queue.put(data);
				System.out.println(Thread.currentThread().getName()+" produce:" + data);
			}
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

import java.util.concurrent.BlockingQueue;

/**
 * 
 * 类功能描述：消费者
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-4-2 上午11:02:22
 */
public class Consumer extends AbstractPC{
	
	private static final int SLEEP_TIME = 3000;
	
	public Consumer(BlockingQueue<MyData> queue) {
		this.queue = queue;
	}

	public void run() {
		System.out.println("Consumer："+Thread.currentThread().getName()+" start");
		try {
			while(isRunning){
				Thread.sleep(SLEEP_TIME);
				MyData data = queue.take();
				if (null != data) {
					System.out.println(Thread.currentThread().getName()+" consume:"+data);
				}
			}
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;

/**
 * 
 * 类功能描述：完全利用并发包的特性，最优的实现方式。
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-3-28 下午01:10:51
 */
public class Main {
	public static void main(String[] args) throws InterruptedException {
		BlockingQueue<MyData> queue = new LinkedBlockingQueue<MyData>(10);
		Producer producer = new Producer(queue);
		Consumer consumer = new Consumer(queue);
		ExecutorService service = Executors.newCachedThreadPool();
		service.execute(producer);
		service.execute(producer);
		service.execute(producer);
		service.execute(consumer);
		Thread.sleep(10000);
		producer.stop();
		System.out.println("producer stop!");
		Thread.sleep(10000);
		System.out.println("consumer stop!");
		consumer.stop();
		service.shutdown();
	}
}

//下面是链式阻塞队列的内部简单实现
public interface BlockingQueue<T> {
	
	/**
	 * 
	 * @function:插入元素
	 * @param e
	 * @throws InterruptedException
	 * @author: mengqingyu    2013-4-2 上午10:39:19
	 */
	void put(T e) throws InterruptedException;
	
	/**
	 * 
	 * @function:取出元素
	 * @return
	 * @throws InterruptedException
	 * @author: mengqingyu    2013-4-2 上午10:39:16
	 */
	T take() throws InterruptedException;
}

/**
 * 
 * 类功能描述：阻塞队列的内部实现
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp @param <T> $
 * Create:  2013-4-2 上午11:04:29
 */
public class LinkedBlockingQueue<T> implements BlockingQueue<T>{

	//链表容量
    private final int capacity;

    //计数器
    private final AtomicInteger count = new AtomicInteger(0);

    //队列头引用
    private transient Node<T> head;

    //队列尾引用
    private transient Node<T> last;
    
    //锁
	private Lock lock = new ReentrantLock();  
	
	//生产者条件锁
	private Condition condition_producer = lock.newCondition();  
	
	//消费者条件锁
    private Condition condition_consumer = lock.newCondition(); 
	
    //链表内部类
    static class Node<T> {
        volatile T item; //数据区
        Node<T> next;	//后继结点
        Node(T x) { item = x; }
    }
    
    public LinkedBlockingQueue(int capacity) {
        if (capacity <= 0) throw new IllegalArgumentException();
        this.capacity = capacity;
        last = head = new Node<T>(null);
    }
    
	@Override
	public void put(T t) throws InterruptedException {
		if (t == null) throw new NullPointerException();
        lock.lock();
        try { 
			while (count.get() == capacity)	//当容量满时候等待，用循环的目的是每次被唤醒都需要重新检查是否满足条件。
				condition_producer.await();  
			insert(t);//插入元素
        	System.out.println(Thread.currentThread().getName()+" push:"+(capacity-1)+t);
            count.getAndIncrement();//计数器加1
            condition_consumer.signalAll();
		} catch (InterruptedException e) {
			condition_consumer.signalAll(); 
			e.printStackTrace();
		}
		finally {
			lock.unlock();
		}
	}

	/**
	 * 
	 * @function:插入元素
	 * @param x
	 * @author: mengqingyu    2013-4-2 上午10:36:52
	 */
    private void insert(T x) {
        last = last.next = new Node<T>(x);
    }
    
	@Override
	public T take() throws InterruptedException {
		T x = null;
		lock.lock();
		try{
			while (count.get() == 0)
				condition_consumer.await();
			x = extract();
			System.out.println(Thread.currentThread().getName()+" pop:"+capacity+x);
			count.getAndDecrement();
			condition_producer.signalAll(); 
		} catch (InterruptedException e) {
			condition_producer.signalAll(); 
			e.printStackTrace();
		}
		finally {
			lock.unlock();
		}
		return x;
	}
	
	/**
	 * 
	 * @function:取出元素
	 * @return
	 * @author: mengqingyu    2013-4-2 上午10:36:31
	 */
    private T extract() {
        Node<T> first = head.next;
        head = first;
        T x = first.item;
        first.item = null;
        return x;
    }
}

2.future模式
        从java 5开始，Java提供了Callable接口，该接口是Runnable接口的增强版，Callable接口提供了一个call()方法，可以作为线程执行体，但call()方法比run()方法的功能更强大。
call()方法可以有返回值，call()方法可以声明抛出异常。

import java.util.concurrent.Callable;

/**
 * 
 * 类功能描述：实现Callable接口重写call方法，支持多线程下抛出异常，主线程阻塞等待子线程的返回值。
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-4-2 上午11:06:47
 */
public class DataService implements Callable<String> {
	
    private String param;
    
    private static final int SLEEP_TIME = 1000;
    
    public DataService(String param){
    	this.param = param;
    }
    
	@Override
	public String call() throws InterruptedException{
    	StringBuffer sb=new StringBuffer();
        for (int i = 0; i < 5; i++) {
        	sb.append(param);
        	System.out.println("Chlid Thread wait 1 second...");
			Thread.sleep(SLEEP_TIME);
        }
        return sb.toString();
	}
}

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;

/**
 * 
 * 类功能描述：jdk实现，可以直接使用
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp  $
 * Create:  2013-3-28 下午01:11:43
 */
public class Main {
    public static void main(String[] args) {
        FutureTask<String> future = new FutureTask<String>(new DataService("Hello "));
        ExecutorService executor = Executors.newFixedThreadPool(1);
        try {
            executor.execute(future);
        	System.out.println("Main Thread wait 2 second...");
            Thread.sleep(2000);
        } catch (InterruptedException e) {
        	e.printStackTrace();
        }
        System.out.println("future.get() before");
        try {
			System.out.println("result:" + future.get());//线程阻塞，直到取到返回值
		} catch (Exception e) {
			e.printStackTrace();
		} 
		executor.shutdown();
    }
}

//下面是future的内部实现
public interface Callable<T> {
	T call() throws Exception;;
}

public interface Future<T> {
    T get()throws Exception;
}

/**
 * 
 * 类功能描述：future内部实现，包含获取结果集和异常信息的方法
 *
 * @author <a href="mailto:[e-mail]">mengqingyu </a>
 * @version $Id: codetemplates.xml,v 1.1 2009/03/06 01:13:01 mengqingyu Exp @param <T> $
 * Create:  2013-4-2 上午11:08:52
 */
public class FutureTask<T> implements Future<T>,Runnable {
	
	private T data;
    
    private Exception exception;
    
    private Callable<T> callable;
    
    private boolean isReady = false;
    
    public FutureTask(Callable<T> callable) {
    	this.callable =  callable;
	}
    
    public synchronized T get() throws Exception {
        while (!isReady) {
            try {
                wait();
            } catch (InterruptedException e) {
            	e.printStackTrace();
            }
        }
        if (exception != null)
        	 throw exception;
        return data;
    }

	@Override
	public synchronized void run() {
        if (isReady) {                        
            return;     
        }
		try {
			data = callable.call();
		} catch (Exception e) {
			exception = e;
		}
		isReady = true;
		notifyAll();
	}
}