java - 如何在简单的现金存取程序中处理多线程

Question

<分区>

Answer 1

账户类别

public class Account {
public static Account account;
private static int balance = 1000;
private static Person person;

private Account() {
}

public static Account getAccount(Person p) {
    if (account == null) {
        account = new Account();
    }
    Account.person = p;
    return account;
}

public static int getBal() {
    return balance;
}

public synchronized void withdraw(int bal) {
    try {

        if (balance >= bal) {
            System.out.println(person.getName() + " " + "is try to withdraw");
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                e.printStackTrace();
            }
            balance = balance - bal;
            System.out.println(person.getName() + " " + "is complete the withdraw");
        } else {
            System.out.println(person.getName() + " " + "doesn't have enough money for withdraw ");
        }
        System.out.println(person.getName() + " " + " withdraw Rs." + balance);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public synchronized void deposit(int bal) {
    try {
        if (bal > 0) {
            System.out.println(person.getName() + " " + " is try to deposit");
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                e.printStackTrace();
            }
            balance = balance + bal;
            System.out.println(person.getName() + " " + "is complete the deposit");
        } else {
            System.out.println(person.getName() + " " + "doesn't have enough money for deposit");
        }
        System.out.println(person.getName() + " " + " deposit Rs." + balance);
    } catch (Exception e) {
        e.printStackTrace();
    }
}}

人物类

public class Person {
private String name;

public Person(String name) {
    this.name = name;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

@Override
public String toString() {
    return name;
}}

ThreadExercise 类

public class ThreadExercise extends Thread implements Runnable {

private Person person;

public ThreadExercise(Person p) {
    this.person = p;
}

public static void main(String[] args) {

    ThreadExercise ts1 = new ThreadExercise(new Person("person 1"));
    ts1.start();
    ThreadExercise ts2 = new ThreadExercise(new Person("person 2"));
    ts2.start();
    ThreadExercise ts3 = new ThreadExercise(new Person("person 3"));
    ts3.start();

}

@Override
public void run() {
    for (int i = 0; i < 3; i++) {
        try {
            Account acc = Account.getAccount(person);
            acc.withdraw(100);
            try {
                Thread.sleep(200);
            } catch (InterruptedException ex) {
                Logger.getLogger(ThreadExercise.class.getName()).log(Level.SEVERE, null, ex);
            }
            if (acc.getBal() < 0) {
                System.out.println("account is overdrawn!");
            }
            acc.deposit(200);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    System.out.println("Final Acc balance is Rs." + Account.getBal());
}}