스레드 동기화 예제1 - syncronized

A

public class A {

    private static int a ;
    A(){
        a=15;
    }
    public synchronized void work(){
        a--;
    }
    public int getA(){
        return a;
    }

}

B

public class B extends Thread{
    private A aa ;
    private String name;

    public B(String Name, A Aa){
        name = Name;
        aa = Aa;
    }
    public void run(){
        for(int i=0; i<3; i++){
            aa.work();
            System.out.println(name + "/" + aa.getA());
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
        //System.out.println(name + "/" + aa.getA());
    }
}

C

public class C {
    public static void main(String[] args){

        B[] brr = new B[5];

        for(int i=0; i<5; i++){
            A a = new A();
            brr[i] = new B("Thread"+i, a);
        }

        for(int i=0; i<5; i++){
            brr[i].start();
        }
    }
}

http://changpd.blogspot.kr/2016/03/syncronized.html