java的thread同步: synchronized eentrantLock，扩展CopyOnWriteArrayList

package com.seven.unsafe;
//银行取钱不安全
//synchronized:同步代码块，也可以同步方法。保持需要修改的数据安全
public class UnsafeBank {

    public static void main(String[] args) {
        Account account = new Account(100, "张三");

        Bank bank1 = new Bank(account, 50);
        Bank bank2 = new Bank(account, 100);

        Thread thread1 = new Thread(bank1, "你");
        Thread thread2 = new Thread(bank2, "女朋友");
//        thread1.setPriority(3);
        thread1.start();
//        thread2.setPriority(3);
        thread2.start();

    }
}
//银行账户
class Account {
  private   int money;//钱
  private   String name;//用户名

    public Account(int money, String name) {
        this.money = money;
        this.name = name;
    }

    public int getMoney() {
        return money;
    }

    public void setMoney(int money) {
        this.money = money;
    }

    public String getName() {
        return name;
    }

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

//银行取钱
class Bank implements Runnable{
    private Account account;
    private int drawingMoney;
    private int myMoney;

    public Bank(Account account, int drawingMoney) {
        this.account = account;
        this.drawingMoney = drawingMoney;
    }

    @Override
    public void run() {

        synchronized (account){
            if (account.getMoney()-drawingMoney<0)//账户的钱-要取的钱小于0，返回钱不够
            {
                System.out.println(Thread.currentThread().getName()+"钱不够了，不能取出");
                return;
            }
            //线程休眠：放大事件发生性
//            try {
//                Thread.sleep(1000);
//            } catch (InterruptedException e) {
//                e.printStackTrace();
//            }
            //取钱
            account.setMoney(account.getMoney()-drawingMoney);//账户余额=账户余额-要取的钱
            myMoney = myMoney+drawingMoney;//我的钱=我的钱+要取的钱
            System.out.println(account.getName()+"账户余额"+account.getMoney());
            System.out.println(Thread.currentThread().getName()+"手里的钱"+myMoney);
        }


    }
}

package com.seven.unsafe;

import java.util.concurrent.locks.ReentrantLock;


public class TestReentrantLock {
    public static void main(String[] args) {
        Ticket ticket = new Ticket();

        new Thread(ticket).start();
        new Thread(ticket).start();
        new Thread(ticket).start();
        new Thread(ticket).start();
    }
}
class Ticket implements Runnable{
    int ticketNums = 10;
    private final ReentrantLock lock = new ReentrantLock();//new一个ReentrantLock
    @Override
    public void run() {
        while(true){
            try {
                lock.lock();//加锁
                if (ticketNums<=0) break;
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName()+"拿到了票"+ticketNums--);
            }finally {
                lock.unlock();//解锁
            }
        }
    }
}

package com.seven.unsafe;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

//CopyOnWriteArrayList内部提供了线程安全
public class TestCopyOnWriteArrayList {
    public static void main(String[] args) throws InterruptedException {
//        List list = new ArrayList();
        CopyOnWriteArrayList copyonWriteArrayList = new CopyOnWriteArrayList();

        new Thread(()->{
            for (int i = 0; i < 10000; i++) {
//                list.add(Thread.currentThread().getName());
                copyOnWriteArrayList.add(Thread.currentThread().getName());
            }
        }).start();

        Thread.sleep(3000);

        System.out.println(copyOnWriteArrayList.size());
//        System.out.println(list.size());
    }
}