并发编程

public class MultiThread{

    private static int num=0;
    
    public synchronized void printNum(String tag){
        try{
            if(tag.equals("a")){
                
                num=100;
                System.out.println("tag a,set num over");
                Thread.sleep(1000);
            }else{
                num=200;
                System.out.println("tag b,set num over");
            }
            System.out.println("tag"+tag+",num="+num);
        }catch(InterruptedException e){
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args){
        final MultiThread m1=new MultiThread();
        final MultiThread m2=new MultiThread();
        
        Thread t1=new Thread(new Runnable(){
            public void run(){
                m1.printNum("a");
            }
 大专栏  并发编程        });
        
        Thread t2=new Thread(new Runnable(){
            public void run(){
                m2.printNum("b");
            }
        });
        
        t1.start();
        t2.start();
    }
}

tag a,set num over
tag b,set num over
tagb,num=200
taga,num=200

tag b,set num over
tag a,set num over
tagb,num=100
taga,num=100

tag b,set num over
tag a,set num over
tagb,num=200
taga,num=200

tag a,set num over
tag b,set num over
tagb,num=200
taga,num=100

tag b,set num over
tagb,num=200
tag a,set num over
taga,num=100