package ch;
/**
 * 两个储户到同一个银行存钱，每个人存了三次，每次100元。
 * 1.描述银行
 * 2.描述储户行为
 * @author Administrator
 *
 */

class Bank{
	private int sum;
	private Object lock = new Object();
	
	Bank(){}
	
	public void add(int n) {
		synchronized(lock) {
			sum += n;
		    System.out.println("sum="+sum);
		}
	}
}

class Customer implements Runnable{
	private Bank b = new Bank();
	
	public void run() {
		for(int i = 0;i<3;i++) {
			b.add(100);
		}
	}
}


public class ThreadDemo {
	public static void main(String [] args) {
		Customer c = new Customer();
		
		Thread t1 = new Thread(c);
		Thread t2 = new Thread(c);
		
		t1.start();
		t2.start();
	}
}