• 并发中级(第一篇)

    并发中级篇


    1. JUC概述


    1.1 JUC


    • 在JAVA中，线程部分是一个重点，本篇文章说的是JUC也是关于线程的。JUC就是java.util.concurrent工具包的简称。这是一个处理线程的工具包，JDK1.5开始出现的。

    1.2 线程和进程


    • 进程与线程：
      • 一个进程可包含多个线程
    • 线程的几个状态：
      • 线程状态枚举类：
        • NEW
        • RUNNABLE
        • BLOCKED
        • WAITING
        • TIMED_WAITING
        • TERMINATED
    • wait和sleep：
      • sleep是Thread中的静态方法，wait是Object中的方法，任何对象实例都能调用
      • sleep不会释放锁。wait会释放锁，但是调用它的前提是的当前线程占有锁(即代码要在synchronized中)
      • 他们都可以被interrupt方法中断
    • 并发和并行：
    • 管程：
      • 线程操作，首先持有管程对象，然后才能执行方法。当在方法中，其余的线程不能再获取同一个管程对象；在方法运行完之后，最后再释放管程对象。
    • 用户线程和守护线程：
      • 用户线程：自定义线程
      • 守护线程：比如说垃圾回收，运行在后台

    2. Lock接口


    2.1 Synchronized


    • Synchronized作用范围
      • 1.修饰一个代码块
      • 2.修饰一个方法，被修饰的方法称为同步方法。
      • 3.修改一个静态方法，其作用范围是整个静态方法。作用的对象是这个类的所有对象。
      • 4.修改一个类，其作用范围是synchronized后面括号括起来的部分，作用对象是这个类的所有对象
    • Synchronized实现卖票例子
    • 多线程编程步骤(上)
      • 1.创建资源类，在资源类创建属性和操作方法
      • 2.创建多个线程，调用资源类的操作方法
    package com.atguigu.sync;
//1.第一步：创建资源类，定义属性和方法
class Ticket{
    //票数
    private int number = 30;

    //操作方法
    public synchronized void sale(){
        //卖票过程
        if(number>0){
            System.out.println(Thread.currentThread().getName()+":还有:" + (number--)
                    + ",卖出后剩下:" + number);
        }
    }
}






public class SaleTicket {

    //第二步：创建多个线程
    public static void main(String[] args) {
        //创建Ticket对象
        Ticket ticket = new Ticket();
        //创建三个线程
       new Thread(new Runnable() {
           @Override
           public void run() {
               //调用卖票方法

               for(int i=0; i<40; i++){
                   ticket.sale();

               }
           }
       },"AA").start();


       //第二个线程
        new Thread(new Runnable() {
            @Override
            public void run() {
                //调用卖票方法

                for(int i=0; i<40; i++){
                    ticket.sale();

                }
            }
        },"BB").start();


        //第三个线程
        new Thread(new Runnable() {
            @Override
            public void run() {
                //调用卖票方法

                for(int i=0; i<40; i++){
                    ticket.sale();

                }
            }
        },"CC").start();




    }

}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    • 72
    • 73
    • 74
    • 75
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=56685:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.sync.SaleTicket
AA:还有:30,卖出后剩下:29
AA:还有:29,卖出后剩下:28
AA:还有:28,卖出后剩下:27
AA:还有:27,卖出后剩下:26
AA:还有:26,卖出后剩下:25
AA:还有:25,卖出后剩下:24
AA:还有:24,卖出后剩下:23
AA:还有:23,卖出后剩下:22
AA:还有:22,卖出后剩下:21
AA:还有:21,卖出后剩下:20
AA:还有:20,卖出后剩下:19
AA:还有:19,卖出后剩下:18
AA:还有:18,卖出后剩下:17
AA:还有:17,卖出后剩下:16
AA:还有:16,卖出后剩下:15
AA:还有:15,卖出后剩下:14
AA:还有:14,卖出后剩下:13
AA:还有:13,卖出后剩下:12
AA:还有:12,卖出后剩下:11
AA:还有:11,卖出后剩下:10
AA:还有:10,卖出后剩下:9
AA:还有:9,卖出后剩下:8
AA:还有:8,卖出后剩下:7
AA:还有:7,卖出后剩下:6
AA:还有:6,卖出后剩下:5
AA:还有:5,卖出后剩下:4
AA:还有:4,卖出后剩下:3
AA:还有:3,卖出后剩下:2
AA:还有:2,卖出后剩下:1
AA:还有:1,卖出后剩下:0

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34

    2.2 Lock接口


    • Lock锁提供了比使用synchronized同步方法和语句可以获得更多的操作
    • Lock不是java内置的，synchronized是java内置的
    • synchronized是自动上锁，自动释放锁；lock是手动上锁，手动释放锁
    • lock可以响应中断，但是synchronized无法响应中断
      package com.atguigu;

import java.util.concurrent.locks.ReentrantLock;

//1.第一步：创建资源类，定义属性和方法
class LTicket{
    //票数
    private int number = 30;

    //操作方法
    private final ReentrantLock lock = new ReentrantLock();
    public  void sale(){
        //卖票过程
        lock.lock();
        try {
            if (number > 0) {
                System.out.println(Thread.currentThread().getName() + ":还有:" + (number--)
                        + ",卖出后剩下:" + number);
            }
        }finally {
            lock.unlock();
        }
    }
}





public class LSaleTicket {




    public static void main(String[] args) {

        //
        LTicket ticket = new LTicket();

        //创建线程的方式



        new Thread(()->{				//lang表达式
            for(int i=0; i<40; i++){
                ticket.sale();
            }
        },"AA").start();


        new Thread(()->{
            for(int i=0; i<40; i++){
                ticket.sale();
            }
        },"BB").start();


        new Thread(()->{
            for(int i=0; i<40; i++){
                ticket.sale();
            }
        },"CC").start();





    }

}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=56749:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.LSaleTicket
AA:还有:30,卖出后剩下:29
AA:还有:29,卖出后剩下:28
AA:还有:28,卖出后剩下:27
AA:还有:27,卖出后剩下:26
AA:还有:26,卖出后剩下:25
BB:还有:25,卖出后剩下:24
BB:还有:24,卖出后剩下:23
BB:还有:23,卖出后剩下:22
BB:还有:22,卖出后剩下:21
BB:还有:21,卖出后剩下:20
BB:还有:20,卖出后剩下:19
BB:还有:19,卖出后剩下:18
BB:还有:18,卖出后剩下:17
BB:还有:17,卖出后剩下:16
BB:还有:16,卖出后剩下:15
BB:还有:15,卖出后剩下:14
BB:还有:14,卖出后剩下:13
BB:还有:13,卖出后剩下:12
BB:还有:12,卖出后剩下:11
BB:还有:11,卖出后剩下:10
BB:还有:10,卖出后剩下:9
BB:还有:9,卖出后剩下:8
BB:还有:8,卖出后剩下:7
BB:还有:7,卖出后剩下:6
BB:还有:6,卖出后剩下:5
BB:还有:5,卖出后剩下:4
BB:还有:4,卖出后剩下:3
BB:还有:3,卖出后剩下:2
BB:还有:2,卖出后剩下:1
BB:还有:1,卖出后剩下:0

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34

    2.3 创建多线程的多种方式



    2.4 使用LOCK实现卖票



    3. 线程间的通信


    • 多线程步骤：
      • 1.创建资源类，在资源类创建属性和操作方法
      • 2.在资源类操作方法
        • (1).判断
        • (2).干活
        • (3).通知
      • 3.创建多个线程，调用资源类的操作方法
    package com.atguigu.sync;

//创建一个资源类
class Share {
    private int number = 0;

    //+1的方法
    public synchronized void incr() throws InterruptedException {
        if (number != 0) {
            //判断number是否为0,如果不为0，等待
            this.wait();
        }
        //如果number=0，+1
        number++;
        System.out.println(Thread.currentThread().getName() + "::" + number);
        //通知其他线程
        this.notifyAll();
    }

    //-1的方法
    public synchronized void decr() throws InterruptedException {
        if(number!=1){
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName() + "::" + number);
        this.notifyAll();
    }
}



public class ThreadDemo01 {
    public static void main(String[] args) {
        //第三步：创建多个线程，调用资源类的操作方法
        Share share = new Share();

        //创建线程
        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.incr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"AA").start();


        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.decr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();


    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=56980:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.sync.ThreadDemo01
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24

    虚假唤醒问题解决方案：

    while(number != 1){	//将判断条件改为循环的形式
	this.wait();
}

    • 1
    • 2
    • 3
    package com.atguigu.sync;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

//创建资源类
class Share1 {
    private int num=0;

    private Lock lock = new ReentrantLock();
    private Condition condition = lock.newCondition();


    //+1方法
    public void incr() throws InterruptedException {
        //上锁
        lock.lock();
        try{
            //判断
            while(num != 0){
                condition.await();
            }
            //干活
            num++;
            System.out.println(Thread.currentThread().getName() + "::" + num);
            //通知
            condition.signalAll();
        }  finally{
            //解锁操作
            lock.unlock();
        }
    }

    //-1方法
    public void decr() throws InterruptedException {
        lock.lock();
        try{
            //判断
            while(num!=1){
              condition.await();
            }
            //操作
            num--;
            //通知
            condition.signalAll();
        }finally{
            lock.unlock();
        }
    }

}




public class ThreadDemo2 {
    public static void main(String[] args) {

        Share share = new Share();
        //线程AA
        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.incr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"AA").start();


        //线程BB
        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.decr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();

        //线程CC
        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.incr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"CC").start();

        //线程DD
        new Thread(()->{
            for(int i=1;i<=10;i++){
                try {
                    share.decr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"DD").start();

    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    • 72
    • 73
    • 74
    • 75
    • 76
    • 77
    • 78
    • 79
    • 80
    • 81
    • 82
    • 83
    • 84
    • 85
    • 86
    • 87
    • 88
    • 89
    • 90
    • 91
    • 92
    • 93
    • 94
    • 95
    • 96
    • 97
    • 98
    • 99
    • 100
    • 101
    • 102
    • 103
    • 104
    • 105
    • 106
    • 107
    • 108
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=57137:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.sync.ThreadDemo2
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
AA::1
BB::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0
CC::1
DD::0

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44

    在这里插入图片描述


    4. 线程间定制化通信


    • 启动三个线程，按照如下的要求进行操作：
      • AA打印5次，BB第二执行，CC打印15
      • AA打印5次，BB第二执行，CC打印15
    package com.atguigu.sync;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

//创建资源类
class ShareResource{
    //属性:标志位
    private int flag = 1;//1AA  2BB  3CC
    //创建Lock锁
    private Lock lock = new ReentrantLock();
    //创建三个condition
    private Condition c1 = lock.newCondition();
    private Condition c2 = lock.newCondition();
    private Condition c3 = lock.newCondition();

    //打印5次
    public void print5(int loop) throws InterruptedException {
        //上锁
        lock.lock();
        try{
            //判断
            while(flag!=1){
                //等待
                c1.await();
            }
            //干活
            for(int i=1; i<=5; i++){
                System.out.println(Thread.currentThread().getName()+ "::" + i + ":轮数：" + loop);
            }

            //通知
            flag = 2;//先修改标志位
            c2.signal();//在通知BB线程

        }finally{
            //释放锁
            lock.unlock();
        }
    }


    //打印10次
    public void print10(int loop) throws InterruptedException{
        lock.lock();
        try{//等待
            while(flag!=2){
                c2.await();
            }
            //干活
            for(int i=1; i<=10; i++){
                System.out.println(Thread.currentThread().getName()+ "::" + i + ":轮数：" + loop);
            }
            //通知
            flag=3;
            c3.signal();
        }finally{
            lock.unlock();
        }

    }


    //打印15次
    public void print15(int loop) throws InterruptedException{
        lock.lock();
        try{//等待
            while(flag!=3){
                c3.await();
            }
            //干活
            for(int i=1; i<=10; i++){
                System.out.println(Thread.currentThread().getName()+ "::" + i + ":轮数：" + loop);
            }
            //通知
            flag=1;
            c1.signal();
        }finally{
            lock.unlock();
        }
    }

}

public class ThreadDemo3 {

    public static void main(String[] args) {
        //创建资源
        ShareResource shareResource = new ShareResource();

        //创建三个线程
        new Thread(()->{
            for(int i=1; i<=10; i++){
                try {
                    shareResource.print5(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            } 
        },"AA").start();


        new Thread(()->{
            for(int i=1; i<=10;i++){
                try {
                    shareResource.print10(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();


        new Thread(()->{
            for(int i=1; i<=10;i++){
                try {
                    shareResource.print15(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"CC").start();




    }

}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    • 72
    • 73
    • 74
    • 75
    • 76
    • 77
    • 78
    • 79
    • 80
    • 81
    • 82
    • 83
    • 84
    • 85
    • 86
    • 87
    • 88
    • 89
    • 90
    • 91
    • 92
    • 93
    • 94
    • 95
    • 96
    • 97
    • 98
    • 99
    • 100
    • 101
    • 102
    • 103
    • 104
    • 105
    • 106
    • 107
    • 108
    • 109
    • 110
    • 111
    • 112
    • 113
    • 114
    • 115
    • 116
    • 117
    • 118
    • 119
    • 120
    • 121
    • 122
    • 123
    • 124
    • 125
    • 126
    • 127
    • 128
    • 129
    • 130
    • 131

    5. 集合的线程安全


    线程安全与县城不安全的含义


    5.1 集合线程不安全演示


    package com.atguigu.sync;
/*
*   list集合线程不安全
*
*/

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

public class ThreadDemo4 {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();

        for(int i=0; i<30; i++){
            new Thread(()->{
                //向集合中添加内容
                list.add(UUID.randomUUID().toString().substring(0,8));
                //从集合中获取内容
                System.out.println(list);
            },String.valueOf(i)).start();
        }


    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=57347:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.sync.ThreadDemo4
[aadea00b, ae5a5aa6]
[aadea00b, ae5a5aa6, 940e1a33]
[aadea00b, ae5a5aa6]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d, a0d05cd6]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d, a0d05cd6, 41b0804e]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d, a0d05cd6, 41b0804e, 5f4a2711]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d, a0d05cd6, 41b0804e, 5f4a2711, dc55e916]
[aadea00b, ae5a5aa6, 940e1a33, 1ec708cb, bc4f7130, da4e83cd, 8c063487, e9f50606, 9f580680, 6007e631, 5c0c046e, 5a539b10, 048d2bc8, 75c093e2, 5dc8d0a8, e3192fbc, b7bfad0c, 722f6e43, 36f20de3, a3cb0146, b4614891, 968399d4, 32c5652e, 60b1002c, c9d5db9d, a0d05cd6, 41b0804e, 5f4a2711, dc55e916, 270dba75]
Exception in thread "17" Exception in thread "2" java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at java.util.AbstractCollection.toString(AbstractCollection.java:461)
	at java.lang.String.valueOf(String.java:2994)
	at java.io.PrintStream.println(PrintStream.java:821)
	at com.atguigu.sync.ThreadDemo4.lambda$main$0(ThreadDemo4.java:20)
	at java.lang.Thread.run(Thread.java:748)
java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at java.util.AbstractCollection.toString(AbstractCollection.java:461)
	at java.lang.String.valueOf(String.java:2994)
	at java.io.PrintStream.println(PrintStream.java:821)
	at com.atguigu.sync.ThreadDemo4.lambda$main$0(ThreadDemo4.java:20)
	at java.lang.Thread.run(Thread.java:748)

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48

    5.2 解决方案-vector


    vector源代码：

    /**
     * Adds the specified component to the end of this vector,
     * increasing its size by one. The capacity of this vector is
     * increased if its size becomes greater than its capacity.
     *
     * 
    This method is identical in functionality to the
     * {@link #add(Object) add(E)}
     * method (which is part of the {@link List} interface).
     *
     * @param   obj   the component to be added
     */
    public synchronized void addElement(E obj) {
        modCount++;
        ensureCapacityHelper(elementCount + 1);
        elementData[elementCount++] = obj;
    }

    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    package com.atguigu.sync;
/*
*   list集合线程不安全
*
*/

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import java.util.Vector;

public class ThreadDemo4 {
    public static void main(String[] args) {
        //创建ArrayList集合
//        List list = new ArrayList<>();
        List<String> list = new Vector<>();

        for(int i=0; i<30; i++){
            new Thread(()->{
                //向集合中添加内容
                list.add(UUID.randomUUID().toString().substring(0,8));
                //从集合中获取内容
                System.out.println(list);
            },String.valueOf(i)).start();
        }


    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    "C:\Program Files\Java\jdk1.8.0_152\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2020.2.4\lib\idea_rt.jar=57370:D:\IntelliJ IDEA 2020.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_152\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\day01\out\production\day01;C:\Users\Administrator\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\Administrator\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.atguigu.sync.ThreadDemo4
[c4689892, 90a47afe, b554b86a]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828]
[c4689892, 90a47afe, b554b86a, 8a79cbf2]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810, fabd7978, 8a92c59a]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810, fabd7978, 8a92c59a, 56c43004]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810, fabd7978, 8a92c59a, 56c43004]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810, fabd7978]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e]
[c4689892, 90a47afe, b554b86a, 8a79cbf2, 094c3828, 07b0c7d0, 98f98527, 4410a510, 1d9a70da, 0bb1269d, d3d5350e, 85444775, 3a909675, e86e5c31, 4c2e2b27, b8b7e65b, 6b4ad455, dd134c0d, 3e86df48, cf282a62, a41287c0, 25633381, 36bb706c, 888e3b81, 1dc2eedf, 24642a40, a6327810, fabd7978, 8a92c59a]

Process finished with exit code 0


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34

    5.3 解决方案-Collection


    java的Collections.synchronizedList方法解决线程安全问题：

    package com.atguigu.sync;
/*
*   list集合线程不安全
*
*/

import java.util.*;

public class ThreadDemo4 {
    public static void main(String[] args) {
        //创建ArrayList集合
        List<String> list = Collections.synchronizedList(new ArrayList<>());

        for(int i=0; i<30; i++){
            new Thread(()->{
                //向集合中添加内容
                list.add(UUID.randomUUID().toString().substring(0,8));
                //从集合中获取内容
                System.out.println(list);
            },String.valueOf(i)).start();
        }


    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26

    5.4 解决方案-CopyOnWriteArrayList类


    • 写时复制技术 ：
    package com.atguigu.sync;
/*
*   list集合线程不安全
*
*/

import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;

public class ThreadDemo4 {
    public static void main(String[] args) {
        //创建ArrayList集合
        List<String> list = new CopyOnWriteArrayList<>();

        for(int i=0; i<30; i++){
            new Thread(()->{
                //向集合中添加内容
                list.add(UUID.randomUUID().toString().substring(0,8));
                //从集合中获取内容
                System.out.println(list);
            },String.valueOf(i)).start();
        }
  

    }
}


    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27

    5.5 HashSet 与 HashMap

    • Set set = new CopyOnWriteArraySet<>(); 创建set对象解决方案
    • Map map = new ConcurrentHashMap<>();创建map对象解决方案
  • 相关阅读:
    HBuilder开发者必备！Windows上传IPA文件的软件分享
    python数据可视化-matplotlib入门(3)-利用随机函数生成变化图形2
    学习笔记——数据结构与算法之美_极客时间
    视频播放器（二）：视频解码
    学习C++第二课
    AWS账号注册以及Claude 3 模型使用教程!
    OkHttp原理 一篇文章就够了
    Node js 开发入门 —UDP 编程，小白也能轻松学会
    C++特色家政服务管理系统
    ProGAN 论文精读
  • 原文地址：https://blog.csdn.net/qq_25355771/article/details/126508229