//DepositInBank.java
public class DepositInBank
{
  public static void main(String[] args)
{
     	 BankAccount ba=new BankAccount();//创建一个银行帐户ba
      ThreadGroup tg=new ThreadGroup("BankClient Group");
for(int i=0;i<5;i++){//模拟5位银行客户同时操作帐户ba
   	      Thread t=new Thread(tg,new BankClient(ba));
   	      t.start();
   	 }
   	  while(tg.activeCount()!=0){}
   	  //操作结束后统计帐户ba的余额
   	  System.out.println("BankAccount balance is:"+ba.getBalance());
   }
}
class BankAccount 
{    //银行帐户类
   private int balance;  //余额属性
   BankAccount()
   {
   	balance=0;
   }
   int getBalance()
   {return balance;}
   void add()                    //向帐户汇款1000元
   {
     int newBalance=balance+1000;
   	try
   	{Thread.sleep(1);}     //这里用Thread.sleep(1)语句模拟银行交易处理的延迟
   	catch(InterruptedException e)
   	{System.out.println(e);}
   	balance=newBalance;
    }
}
class BankClient extends Thread  //银行客户类，每个客户都持有一个帐户
{
   	BankAccount ba;
   	BankClient(BankAccount ba)
   	{
   		this.ba=ba;
      }
   	public void run()              //客户的行为，向帐户汇款
   	{
   	   ba.add();
   	}
}