[Head First Java]-Thread sharing data problem

Reference-P507

1. Description

1. Two threads share the same data. Every time you use data, you need to first determine whether it is within a reasonable range.
2. Use the Thread.sleepfunction to block the thread every time the data is used

2. Code

class BankAccount {
    
    
    private int balance = 100;

    public int getBalance() {
    
    
        return balance;
    }

    public void withdraw(int amount) {
    
    
        balance = balance - amount;
    }
}

public class RyanAndMonicaJob implements Runnable {
    
    
    private BankAccount account = new BankAccount();

    public static void main (String[] args) {
    
    
        RyanAndMonicaJob theJob = new RyanAndMonicaJob();
        Thread one = new Thread(theJob);
        Thread two = new Thread(theJob);
        one.setName("Ryan");
        two.setName("Monica");
        one.start();
        two.start();
    }

    public void run() {
    
    
        for (int x = 0; x < 10; x++) {
    
    
            makeWithdrawal(10);
            if(account.getBalance() < 0) {
    
    
                System.out.println("Overdrawn!");
            }
        }
    }

    private void makeWithdrawal(int amount) {
    
    
        String currentThread = Thread.currentThread().getName();
        if(account.getBalance() >= amount) {
    
    
            System.out.println(currentThread + "is about to withdraw");
            try{
    
    
                System.out.println(currentThread + " is going to sleep");
                Thread.sleep(500);
            } catch(InterruptedException ex) {
    
    
                ex.printStackTrace();
            }
            System.out.println(currentThread + " woke up.");
            account.withdraw(amount);
            System.out.println(currentThread + " completes the withdrawl");
        } else {
    
    
            System.out.println("Sorry, not enough for " + currentThread);
        }
    }
}
```![在这里插入图片描述](https://img-blog.csdnimg.cn/20201113004828229.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BpYW5vOTQyNQ==,size_16,color_FFFFFF,t_70#pic_center)