Java并发学习之十四——使用Lock同步代码块-蒲公英云

Java并发学习之十四——使用Lock同步代码块

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Java提供另外的机制用来同步代码块。它比synchronized关键字更加强大、灵活。Lock 接口比synchronized关键字提供更多额外的功能。在使用Lock时需要注意的是要释放Lock锁。

package chapter2;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/*
 * 打印队列
 */
public class PrintQueue {
    private final Lock queueLock = new ReentrantLock();
    public void printJob(Object document){
        queueLock.lock();//获取Lock对象的控制权
        try {
            Long duration = (long)(Math.random()*10000);
            System.out.println(Thread.currentThread().getName()
                    +"PrintQueue:Printing a Job during "
                    +(duration/1000)+" seconds");
            Thread.sleep(duration);            
        } catch (Exception e) {
            e.printStackTrace();
        } finally{
            queueLock.unlock();//释放Lock对象的控制
        }
    }
}
package chapter2;
public class Job implements Runnable{
    private PrintQueue printQueue;
    public Job(PrintQueue printQueue){
        this.printQueue = printQueue;
    }
    @Override
    public void run() {
        System.out.printf("%s:Going to print a document\n", 
                Thread.currentThread().getName());
        printQueue.printJob(new Object());
        System.out.printf("%s:The document has been printed\n",Thread.currentThread().getName());
    }
}
package chapter2;
/**
 * 
 * <p>
 * Description: 使用Lock同步代码块
 * </p>
 * @author zhangjunshuai
 * @version 1.0
 * Create Date: 2014-9-16 下午4:57:06
 * Project Name: Java7Thread
 *
 * <pre>
 * Modification History: 
  *             Date                                Author                   Version          Description 
 * -----------------------------------------------------------------------------------------------------------  
 * LastChange: $Date::             $      $Author: $          $Rev: $         
 * </pre>
 *
 */
public class Main5 {
    /**
     * <p>
     * </p>
     * @author zhangjunshuai
     * @date 2014-9-16 下午4:57:00
     * @param args
     */
    public static void main(String[] args) {
        PrintQueue printQueue = new PrintQueue();
        Thread thread[] = new Thread[10];
        for(int i=0;i<10;i++){
            thread[i] = new Thread(new Job(printQueue),"Thread"+i);
        }
        for(int i=0;i<10;i++){
            thread[i].start();
        }
    }
}