使用synchronized和Lock对象获取对象锁
package com.tch.test.concurrent;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;public class SynchronizedTest {private ExecutorService pool = Executors.newFixedThreadPool(4);private Lock lock = new ReentrantLock();public static void main(String[] args) {new SynchronizedTest().test();}public void test() {Runnable runnable = null;for(int i=0;i<4;i++){runnable = new Runnable(){public void run(){while(true){execute();}}};pool.execute(runnable);}}void execute(){lock.lock();//首先获得锁try{System.out.println(Thread.currentThread().getId()+"获得了lock，开始休息");Thread.sleep(300);}catch(Exception e){}finally{System.out.println(Thread.currentThread().getId()+"释放了lock,结束休息");lock.unlock();//最后一定要释放锁}}}
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然后使用java的synchronized关键字实现加锁：
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package com.tch.test.concurrent;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;public class SynchronizedTest {private ExecutorService pool = Executors.newFixedThreadPool(4);//private Lock lock = new ReentrantLock();private Object obj = new Object();public static void main(String[] args) {new SynchronizedTest().test();}public void test() {Runnable runnable = null;for(int i=0;i<4;i++){runnable = new Runnable(){public void run(){while(true){execute();}}};pool.execute(runnable);}}void execute(){synchronized(obj){try {System.out.println(Thread.currentThread().getId()+"获得了obj的锁，开始休息");Thread.sleep(300);System.out.println(Thread.currentThread().getId()+"释放了obj的锁,结束休息");} catch (InterruptedException e) {e.printStackTrace();}}}}?
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Thread-1:synchronized in g()?