java線程同步方法，方法塊區別，java線程同步區別

java線程同步方法，方法塊區別，java線程同步區別

先說同步方法，它到底是鎖定的當前對象，還是當前類

代碼塊1

package com.ssss;public class Thread1 implements Runnable {  //public static Object  o=new Object();    public void run() {    pt();    }        public synchronized void pt(){    int a=0;        //synchronized(o) {               for (int i = 0; i < 5; i++) {             a++;             try {Thread.sleep(1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}                  System.out.println(Thread.currentThread().getName() + " synchronized loop " + i + "++++" + a);               }          //}      }            public static void main(String[] args) {           Thread1 t1 = new Thread1();           Thread1 t2 = new Thread1();           Thread ta = new Thread(t1, "A");           Thread tb = new Thread(t2, "B");           ta.start();           tb.start();      } }

列印出來的結果為

由此可見是當前對象，而A和B是兩個不同的對象，所以列印序列就是混亂的

代碼塊2

看同步塊

package com.ssss;public class Thread1 implements Runnable {  public static Object  o=new Object();    public void run() {    pt();    }        public void pt(){    int a=0;        synchronized(o) {               for (int i = 0; i < 5; i++) {             a++;             try {Thread.sleep(1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}                  System.out.println(Thread.currentThread().getName() + " synchronized loop " + i + "++++" + a);               }          }      }            public static void main(String[] args) {           Thread1 t1 = new Thread1();           Thread1 t2 = new Thread1();           Thread ta = new Thread(t1, "A");           Thread tb = new Thread(t2, "B");           ta.start();           tb.start();      } }

看列印序列

說明同步塊可以鎖定任何對象

就是說同步方法是鎖定當前對象，同步方法塊是可以鎖定任何對象