java多线程编程--工作线程模式《java多线程编程调试模式》

一.本例来自《java多线程编程调试模式》：

题意：模拟流水线上的工人，

 工人一直在流水线上作业，零件（可看作客户端发的请求）一到达，工人就开始进行工作，无零件时工作处于等待状态

具体的业务代码有详注释：

一测试类：

package worker.thread.pattern;public class Main {    public static void main(String[] args) {     Channel channel = new Channel(5);   // Worker Thread数量         channel.startWorkers();         ClientThread alice = new ClientThread("Alice", channel);         ClientThread bobby = new ClientThread("Bobby", channel);         ClientThread chris = new ClientThread("Chris", channel);         alice.start();         bobby.start();         chris.start();         try {             Thread.sleep(5000);         } catch (InterruptedException e) {         }         alice.stopThread();         bobby.stopThread();         chris.stopThread();         channel.stopAllWorkers();    }}

2.客户端类：主要发送工作请求

package worker.thread.pattern;import java.util.Random;/** * 不停的发送请求给工人类 *  * 1.创建请求实例，并将实例发送给管理工人线程的类 *  * @author lxb * */public class ClientThread extends Thread {private final Channel channel;private static final Random random = new Random();private volatile boolean terminated = false; // 停止请求标志public ClientThread(String name, Channel channel) {super(name);this.channel = channel;}public void run() {try {for (int i = 0; !terminated; i++) {try {Request request = new Request(getName(), i);channel.putRequest(request);Thread.sleep(random.nextInt(1000));} catch (InterruptedException e) {terminated = true;}}} finally {System.out.println(Thread.currentThread().getName()+ " is terminated.");}}public void stopThread() {terminated = true;interrupt();}}

3.请求对象：

package worker.thread.pattern;import java.util.Random;/** * 请求实体类 * @author lxb * */public class Request {private final String name; //      private final int number;  //     private static final Random random = new Random();    public Request(String name, int number) {        this.name = name;        this.number = number;    }    public void execute() {        System.out.println(Thread.currentThread().getName() + " executes " + this);        try {            Thread.sleep(random.nextInt(1000));        } catch (InterruptedException e) {        }    }    public String toString() {        return "[ Request from " + name + " No." + number + " ]";    }}

4.请求队列与工人线程管理类：

package worker.thread.pattern;/** * 用来接受客户端线程发来的请求、将请求传递给工人线程，所以至少需要以下数据结构： * 1.一个队列来保存客户端发来的请求，还必须提供两个接口，一个putRequest保存请求， 另一个是取出请求takeRequest * 2.线程池来管理各个工人线程,这个池可以是一个线程数组，数组大小可自定义 *  * @author lxb * */public class Channel {private static final int MAX_REQUEST = 100; // 假设最大的请求队列值private final Request[] requestQueue; // 保存的请求队列private int tail;private int head;private int count; // 请求队列中的请求数量private final WorkerThread[] threadPool; // 工人线程池public Channel(int threads) {this.requestQueue = new Request[MAX_REQUEST];this.head = 0;this.count = 0;this.tail = 0;threadPool = new WorkerThread[threads];for (int i = 0; i < threadPool.length; i++) { threadPool[i] = new WorkerThread("Worker-" + i, this);}}/** * 开启工作线程 */public void startWorkers() {for (int i = 0; i < threadPool.length; i++) {threadPool[i].start();}}public void stopAllWorkers(){for(int i=0;i<threadPool.length;i++){threadPool[i].stopThread();}}/** * 保存客户端发来的工作请求 *  * @param request * @throws InterruptedException  */public synchronized void putRequest(Request request) throws InterruptedException {while (count >= requestQueue.length) {wait();}requestQueue[tail] = request;tail = (tail + 1) % requestQueue.length;count++;notifyAll();}public synchronized Request takeRequest() throws InterruptedException {while (count <= 0) {wait();}Request request = requestQueue[head];head = (head + 1) % requestQueue.length;count--;notifyAll();return request;}}

5工人线程：

package worker.thread.pattern;/** * 工作线程，处理客户端发来的具体的工作请求 * @author lxb * */public class WorkerThread extends Thread{private final Channel channel;private volatile boolean terminated = false;//停止请求标志public WorkerThread(String name,Channel channel){super(name);this.channel = channel;}public void run() {        try {            while (!terminated) {                try {                                                               Request request = channel.takeRequest();                        request.execute();                                          } catch (InterruptedException e) {                    terminated = true;                }                                                           }        } finally {            System.out.println(Thread.currentThread().getName() + " is terminated.");        }    }    public void stopThread() {        terminated = true;        interrupt();    }}