在方法体上和在方法体里使用synchronized的区别

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学习synchronized时，我们可以把synchronized放在方法体上，也可以放在方法体内

拿servlet来说，如果放在方法体上，就会把后面的request阻塞掉:

protected synchronized void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {System.out.println("Hello");synchronized (this) {try {Thread.sleep(Integer.MAX_VALUE);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}PrintWriter writer = response.getWriter();writer.write("get call");writer.flush();}

发多个请求都只能看到一个Hello

如果把synchronized放在方法体内则不会出现以上情况

protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {System.out.println("Hello");synchronized (this) {try {Thread.sleep(Integer.MAX_VALUE);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}PrintWriter writer = response.getWriter();writer.write("get call");writer.flush();}

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