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做再多猜想也不如直接写个案例，验证一下，直接上代码：
public class TestSynchronized { public volatile boolean flag;//通知什么时候发起新的请求
//拿住锁5秒钟,以便对后面请求锁进行阻塞 public synchronized void blockWhile(){ try {
Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } }
//调用该方法时，会被阻塞住 public synchronized void blockMethod(){ if
(!this.flag){this.flag = true;} System.out.println("block Method : " +
System.currentTimeMillis()); } //执行新的方法 public synchronized void newMethod(){
System.out.println("new Method : " + System.currentTimeMillis()); } public
static void main(String[] args) throws InterruptedException { TestSynchronized
testSynchronized = new TestSynchronized(); Thread a = new
Thread(testSynchronized::blockWhile); a.start(); Thread.sleep(10);//确保a线程获得锁
Thread b = new Thread(() -> { for (int i = 0; i < 50;i++){
testSynchronized.blockMethod(); } }); b.start();//b线程阻塞50个方法请求
System.out.println("finish block Method : " + System.currentTimeMillis());
Thread c = new Thread(() -> { int i = 0; while (true){ if
(testSynchronized.flag){ for ( ; i < 50;i++){ testSynchronized.newMethod(); } }
} }); c.start();//c线程在b线程的阻塞方法执行后，才执行新的调用方法，模拟新请求方法和阻塞队列请求方法竞争效果 } }
执行结果如下，执行结果有很强的随机性，增加执行数量或者增加方法执行次数都能大概率出现如下结果：
finish block Method : 1591683424652 block Method : 1591683429643 block Method
: 1591683429643 block Method : 1591683429643 block Method : 1591683429643 new
Method : 1591683429643 new Method : 1591683429643 block Method : 1591683429643
block Method : 1591683429643 block Method : 1591683429643 ......
说明，synchronized是非公平锁，没有浪费线程唤醒阶段的时间，执行新调用的方法，增加吞吐量，缺点是可能会造成饥饿锁。