java多线程学习－多个线程访问对象共享数据的方式

public class MulitThreadShareData {
    
    public static void main(String[] args) {
        final ShareData1 data1 = new ShareData1();
        new Thread(new Runnable() {
            public void run() {
                data1.increment();
            }
        }).start();
        
        new Thread(new Runnable() {
            public void run() {
                data1.decrement();
            }
        }).start();
        
        
        new Thread(new MyRunnable1(data1)).start();
        new Thread(new MyRunnable2(data1)).start();
        
    }
}

class ShareData1 {
    private int j = 0;
    
    
    public void increment(){
        for (int i = 0; i < 10; i++) {
            j++;
            System.out.println(j+" now incre ");
        }
    }
    
    public void decrement(){
        for (int i = 0; i < 10; i++) {
            j--;
            System.err.println(j+" now decre ");
        }
    }
}


class MyRunnable1 implements Runnable{
    
    private ShareData1 data;
    
    public MyRunnable1(ShareData1 data){
        this.data = data;
    }

    public void run() {
        data.decrement();
    }
}



class MyRunnable2 implements Runnable{
    
    private ShareData1 data;
    
    public MyRunnable2(ShareData1 data){
        this.data = data;
    }

    public void run() {
        data.increment();
    }
}