java用两个不同的线程处理单个对象，并提供所需的输出

Question

如果我想用两个不同的线程更新单个对象，我该怎么做

我试过：

public class BankAccount{
private static int balance;

private static void balance(int amt)throws InterruptedException{
    balance = amt;

    Thread thread = new Thread(new Runnable(){
    @Override
    public void run(){

        try {
            balance(10);
            System.out.println("Initial Balance:\t"+balance);
        } catch (InterruptedException ex) {
            System.out.println("Exception"+ex.getMessage());
       }

    }

});
        thread.start();
        TimeUnit.SECONDS.sleep(5);
}
 private static void deposit(int deposit){
        balance+=deposit;
    }

public static void main(String[] args)throws InterruptedException {
    Thread thread = new Thread(new Runnable(){
        @Override
        public void run() {

            deposit(10);
            System.out.println("Balance after deposit\t"+balance);
        }

    });
        thread.start();
        TimeUnit.SECONDS.sleep(5);     
}

}

我知道使用单线程可以获得所需的输出：

初始余额：10 存款后余额：20

但如果有办法处理两个不同的线程

Answer 1

您需要遵循以下步骤：

（1）使用balance作为AtomicInteger使其线程安全

（2）首先定义showBalance()、setBalance(int amt)和deposit(int deposit)方法（在代码中balance(int)命名不正确，请将其称为setBalance(int amt)以使其更有意义）

（3）创建thread1并调用setBalance(int amt)

（4）创建thread2并调用showBalance()

（5）创建thread3并调用deposit(int amt)

（5）启动线程

您可以参考以下代码：

private static AtomicInteger balance = new AtomicInteger();

    private static void showBalance() {
        return balance.get();
    }

    private static void setBalance(int amt) {
        balance.set(amt);
    }

    private static void deposit(int deposit){
       balance.getAndAdd(deposit);
    }

    public static void main(String[] args)throws InterruptedException {
        Thread thread1 = new Thread(new Runnable(){
            @Override
            public void run() {
                setBalance(10);
                System.out.println("Initial Balance\t"+balance);
            }

        });
        thread1.start();
        thread1.join();//join after completion of thread1 
                //(i.e., displays Initial Balance)

        Thread thread2 = new Thread(new Runnable(){
            @Override
            public void run() {
                showBalance();
                System.out.println(" Balance\t"+balance);
            }

        });
       thread2.start();
       thread2.join();

        Thread thread3 = new Thread(new Runnable(){
            @Override
            public void run() {
                deposit(10);
                System.out.println("Balance after deposit\t"+balance);
            }

        });
        thread3.start();
    }