现在我正在玩java中的多线程，我不知道它是如何工作的。。我觉得我在互联网上看到的一个简单的例子中理解了这一点，但不知何故，我无法理解这在我从互联网上找到并修改的银行模拟应用程序中是如何工作的。
以下是我所拥有的：
人员类别：

package threadsproject;

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;
    }
}

帐户类别：

package threadsproject;

public class Account {

    public static int balance;
    public static Account acc;
    private static Person p;

    public static int getBal(){
        return balance;
    }

    public void setBal(int bal){
        Account.balance = bal;
    }

    public static Account getAcc(Person p){
        if(acc == null){
            acc = new Account();
        }
        Account.p = p;
        return acc;

    }

    public synchronized void deposit(int val){
        try{

            if(val > 0){
                System.out.println("Person "+p.getName()+" is making a deposit.");
                try{
                    Thread.sleep(500);
                }catch(Exception e){}
                balance = balance + val;
                System.out.println("Person "+p.getName()+" completed the deposit.");
            }else{
                System.out.println("Can't deposit.");
            }
            System.out.println("Person "+p.getName()+" deposited "+val);

        }catch(Exception e){}
    }

    public synchronized void withdraw(int val){
        try{

            if(balance >= val){
                System.out.println("Person "+p.getName()+" is making a withdraw.");
                try{
                    Thread.sleep(500);
                }catch(Exception e){}
                balance = balance - val;
                System.out.println("Person "+p.getName()+" completed the withdraw.");
            }else{
                System.out.println("Can't withdraw.");
            }
            System.out.println("Person "+p.getName()+" withdrew "+val);

        }catch(Exception e){}
    }

}

螺纹等级：

package threadsproject;

import java.util.Scanner;

public class BankThread extends Thread implements Runnable{

    private Person p;

    public BankThread(Person p){
        this.p = p;
    }

    public void run(){
        for (int i = 0; i < 3; i++) {
            try {
                Account acc = Account.getAcc(p);
                Scanner s = new Scanner(System.in);
                System.out.println("Enter deposit ammount:");
                int dep = s.nextInt();
                acc.deposit(dep);
                try {
                    Thread.sleep(500);
                } catch (InterruptedException ex) { }

                System.out.println("Enter withdrawal ammount:");
                int with = s.nextInt();
                if(with > Account.getBal()){
                    System.out.println("You don't have enough funds.");
                }else{
                    acc.withdraw(with);
                }
                System.out.println("Final balance: "+Account.getBal());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) throws InterruptedException {
        // TODO Auto-generated method stub

        Person p1 = new Person("Person1");
        Person p2 = new Person("Person2");
        Person p3 = new Person("Person3");
        BankThread bt1 = new BankThread(p1);
        bt1.start();
        bt1.join();
        BankThread bt2 = new BankThread(p2);
        bt2.start();
        bt2.join();
        BankThread bt3 = new BankThread(p3);
        bt3.start();
        bt3.join();
    }

}

正如我提到的，这是我发现并修改的一个例子。我认为这是可行的，但不正确。在threads类中，for循环执行每个线程的代码3次。另一个问题是每个线程的帐户余额保持不变。所以，如果我的第一个线程有100个最终余额，那么第二个线程也是这样开始的，100个余额，而不是从0开始。如果我有不同的对象，它应该从0开始，对吗？
这是一个截图。