Java并发学习之十四——使用Lock同步代码块

淡淡的烟草味﹌ 2022-08-12 01:59 132阅读 0赞

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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();
    		}
    	}
    
    }