线程同步的方式

1. 定义account类

package newThread;

import java.util.concurrent.locks.ReentrantLock;

public class Account {
    private String accountNo;
    private double balance;
    public Account() {
        super();
    }
    public Account(String accountNo, double balance) {
        super();
        this.accountNo = accountNo;
        this.balance = balance;
    }
    public String getAccountNo() {
        return accountNo;
    }
    public void setAccountNo(String accountNo) {
        this.accountNo = accountNo;
    }
    public double getBalance() {
        return balance;
    }
    public void setBalance(double balance) {
        this.balance = balance;
    }
    @Override
    public int hashCode() {
        return accountNo.hashCode();
        //返回对象的编码
    }
    @Override
    public boolean equals(Object obj) {
        if(obj!=null&&obj.getClass()==Account.class) {
            Account target=(Account) obj;
            return target.getAccountNo().equals(accountNo);
        }
        return false;
    }
    //②线程同步方法，且synchronized 修饰的方法默认的同步监视器是this
    /*public synchronized void draw(double drawAmount) {
        if(balance>=drawAmount) {
            System.out.println(Thread.currentThread().getName()+"取钱成功！--"+drawAmount);
            try {
                Thread.sleep(1);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            balance-=drawAmount;
            System.out.println("\t余额为："+balance);
        }else {
            System.out.println(Thread.currentThread().getName()+"取钱失败！余额不足");
        }
    }*/
    //③同步锁--可重入锁reentrantlock
    private final ReentrantLock lock=new ReentrantLock();
    public void draw(double drawAmount) {
        lock.lock();
        try {
            if(balance>=drawAmount) {
                System.out.println(Thread.currentThread().getName()+"取钱成功！--"+drawAmount);
                try {
                    Thread.sleep(1);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                balance-=drawAmount;
                System.out.println("\t余额为："+balance);
            }else {
                System.out.println(Thread.currentThread().getName()+"取钱失败！余额不足");
            }
        }
        finally {
            lock.unlock();
        }
    }
}

1. 定义线程类

package newThread;

public class DrawThread extends Thread {
    private Account account;//模拟用户账户
    private double drawAmount;

    public DrawThread(String name, Account account, double drawAmount) {
        super(name);
        this.account = account;
        this.drawAmount = drawAmount;
    }

    @Override
    public void run() {
        /*synchronized (account) {//①同步代码块
            if(account.getBalance()>=drawAmount) {
                System.out.println(getName()+"取钱成功！--"+drawAmount);
                try {
                    Thread.sleep(1);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                account.setBalance(account.getBalance()-drawAmount);
                System.out.println("\t余额为："+account.getBalance());
            }else {
                System.out.println(getName()+"取钱失败！余额不足");
            }
        }*/
        account.draw(drawAmount);
    }


}

3.测试的类：测试①②③种方法实现的线程同步

package newThread;

public class TestDraw {

    public static void main(String[] args) {
        Account acct=new Account("123456780",1000);
        new DrawThread("甲",acct,800).start();
        new DrawThread("乙",acct,800).start();
    }

}