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java：多线程与并发

 1 package com.vince;
 2 
 3 public class ThreadDemo1 {
 4     public static void main(String[] args){
 5         MyThread mt = new MyThread();
 6         //推荐：
 7         MyRunnable mr = new MyRunnable();
 8         Thread t2 = new Thread(mr);
 9 
10         mt.start();//启动线程
11         t2.start();
12     }
13 }
14 
15 
16 /*
17 实现线程的第一种方式:继承thread类
18  */
19 
20 class MyThread extends Thread{
21     public void run(){
22         for (int i = 0; i < 50; i++) {
23             System.out.println(Thread.currentThread().getName()+ "-" + i);
24         }
25     }
26 }
27 
28 /*
29 实现线程的第二种方式:实现Runnable接口;
30  */
31 class MyRunnable implements Runnable{
32     public void run(){
33         for (int i = 0; i < 50; i++) {
34             System.out.println(Thread.currentThread().getName()+ "-" + i);
35         }
36     }
37 }

View Code

 1 package com.vince;
 2 
 3 
 4 /*
 5 线程的休眠
 6 在当前线程的执行中，暂停指定的毫秒数，释放CPU的时间片
 7  */
 8 public class ThreadDemo1 {
 9     public static void main(String[] args){
10         MyThread mt = new MyThread();
11         //推荐：
12         MyRunnable mr = new MyRunnable();
13         Thread t2 = new Thread(mr);
14 
15         mt.start();//启动线程
16         t2.start();
17     }
18 }
19 
20 
21 /*
22 实现线程的第一种方式:继承thread类
23  */
24 
25 class MyThread extends Thread{
26     public void run(){
27         for (int i = 0; i < 50; i++) {
28             System.out.println(Thread.currentThread().getName()+ "-" + i);
29             try {
30                 Thread.sleep(500);
31             } catch (InterruptedException e) {
32                 e.printStackTrace();
33             }
34         }
35     }
36 }
37 
38 /*
39 实现线程的第二种方式:实现Runnable接口;
40  */
41 class MyRunnable implements Runnable{
42     public void run(){
43         for (int i = 0; i < 50; i++) {
44             System.out.println(Thread.currentThread().getName()+ "-" + i);
45             try {
46                 Thread.sleep(500);
47             } catch (InterruptedException e) {
48                 e.printStackTrace();
49             }
50         }
51     }
52 }

View Code

 1 /*
 2     join方法：
 3     加入线程，让调用的线程先执行指定时间或执行完毕
 4  */
 5 
 6 
 7 
 8 public class ThreadDemo2 {
 9     public static void main(String[] args){
10         MyRunable2 mr2 = new MyRunable2();
11         Thread t = new Thread(mr2);
12         t.start();
13 
14         for (int i = 0; i < 50; i++) {
15             System.out.println(Thread.currentThread().getName() + "--"+ i);
16             try {
17                 Thread.sleep(300);
18             } catch (InterruptedException e) {
19                 e.printStackTrace();
20             }
21             if(i==20){
22 //                1.1测试join的作用：
23                 try {
24                     t.join();//让t线程执行完毕
25                 } catch (InterruptedException e) {
26                     e.printStackTrace();
27                 }
28 //                t.interrupt();//中断线程，只是做了一个中断标记
29             }
30 
31         }
32 
33     }
34 }
35 
36 
37 class MyRunable2 implements Runnable{
38     public void run(){
39         for (int i = 0; i < 50; i++) {
40 //            1.2
41             if(Thread.interrupted()){
42                 //测试中断状态，此方法会把中断状态清除
43                 break;
44             }
45             System.out.println(Thread.currentThread().getName() + "--" + i);
46             try{
47                 Thread.sleep(300);
48             }catch (InterruptedException e){
49                 e.printStackTrace();
50                 Thread.currentThread().interrupt();
51             }
52 
53         }
54 
55 
56     }
57 }

join作用：

自定义中断：

 1 /*
 2     join方法：
 3     加入线程，让调用的线程先执行指定时间或执行完毕
 4 
 5     中断线程:
 6     1.使用interrupt方法来中断线程，设置一个中断状态(标记)
 7     2.自定义标记方法(推荐使用)
 8 
 9  */
10 
11 
12 
13 public class ThreadDemo2 {
14     public static void main(String[] args){
15         MyRunable2 mr2 = new MyRunable2();
16         Thread t = new Thread(mr2);
17 //        t.start();
18 
19         MyRunable3 mr3 = new MyRunable3();
20         Thread t2 = new Thread(mr3);
21         t2.start();
22 
23 
24         for (int i = 0; i < 50; i++) {
25             System.out.println(Thread.currentThread().getName() + "--"+ i);
26             try {
27                 Thread.sleep(300);
28             } catch (InterruptedException e) {
29                 e.printStackTrace();
30             }
31             if(i==20){
32 //                1.1测试join的作用：
33                 try {
34                     t.join();//让t线程执行完毕
35                 } catch (InterruptedException e) {
36                     e.printStackTrace();
37                 }
38 //                t.interrupt();//中断线程，只是做了一个中断标记
39                 mr3.flag = false;
40             }
41 
42         }
43 
44     }
45 }
46 
47 
48 class MyRunable2 implements Runnable{
49     public void run(){
50         for (int i = 0; i < 50; i++) {
51 //            1.2
52             if(Thread.interrupted()){
53                 //测试中断状态，此方法会把中断状态清除
54                 break;
55             }
56             System.out.println(Thread.currentThread().getName() + "--" + i);
57             try{
58                 Thread.sleep(300);
59             }catch (InterruptedException e){
60                 e.printStackTrace();
61                 Thread.currentThread().interrupt();
62             }
63 
64         }
65 
66 
67     }
68 }
69 
70 class MyRunable3 implements Runnable{
71     public boolean flag = true;
72     public MyRunable3(){
73         flag = true;
74     }
75     public void run(){
76         int i = 0;
77         while (flag){
78             System.out.println(Thread.currentThread().getName() + "=====" + (i++));
79             try {
80                 Thread.sleep(300);
81             } catch (InterruptedException e) {
82                 e.printStackTrace();
83             }
84         }
85     }
86 }

自定义中断：

 1 public class ThreadDemo3 {
 2     public  static void main(String [] args){
 3         MyRunnable4 mr4 = new MyRunnable4();
 4         Thread t = new Thread(mr4);
 5         // 线程可以分成守护线程和用户线程，当进程中没有用户线程时，JVM会退出
 6         t.setDaemon(true);//把线程设置为守护线程
 7         t.start();
 8 
 9         for (int i = 0; i < 50; i++) {
10             System.out.println("main--:" + i);
11             try {
12                 Thread.sleep(200);
13             } catch (InterruptedException e) {
14                 e.printStackTrace();
15             }
16         }
17 
18 
19     }
20 }
21 
22 class MyRunnable4 implements Runnable{
23     public void run(){
24         for (int i = 0; i < 50; i++) {
25             System.out.println("--" + i);
26             try {
27                 Thread.sleep(500);
28             } catch (InterruptedException e) {
29                 e.printStackTrace();
30             }
31         }
32     }
33 }

守护线程：

 1 public class ThreadDemo3 {
 2     public  static void main(String [] args){
 3         MyRunnable4 mr4 = new MyRunnable4();
 4         Thread t = new Thread(mr4);
 5         // 线程可以分成守护线程和用户线程，当进程中没有用户线程时，JVM会退出
 6         t.setDaemon(true);//把线程设置为守护线程
 7         t.start();
 8 
 9         for (int i = 0; i < 50; i++) {
10             System.out.println("main--:" + i);
11             try {
12                 Thread.sleep(200);
13             } catch (InterruptedException e) {
14                 e.printStackTrace();
15             }
16             if(i==5){
17                 Thread.yield();//让出本次cpu执行的时间片
18             }
19         }
20 
21 
22     }
23 }
24 
25 class MyRunnable4 implements Runnable{
26     public void run(){
27         for (int i = 0; i < 50; i++) {
28             System.out.println("--" + i);
29             try {
30                 Thread.sleep(500);
31             } catch (InterruptedException e) {
32                 e.printStackTrace();
33             }
34         }
35     }
36 }

yield：

 1 public class ThreadDemo4 {
 2 
 3     public static void main(String[] args){
 4         MyRunnable5 mr5 = new MyRunnable5();
 5 
 6         Thread t1 = new Thread(mr5);
 7         Thread t2 = new Thread(mr5);
 8         t1.start();
 9         t2.start();
10     }
11 }
12 
13 class  MyRunnable5 implements  Runnable{
14     //两个线程共享一个数据:ticket
15     private int ticket = 10;//售票
16     public  void run(){
17         for (int i = 0; i < 300; i++) {
18             if(ticket>0){
19                 ticket--;
20 
21                 try {
22                     Thread.sleep(1000);
23                 } catch (InterruptedException e) {
24                     e.printStackTrace();
25                 }
26                 System.out.println("您购买的票剩余" +ticket +"张");
27             }
28         }
29     }
30 }

两个线程共享一个数据(线程不安全示例)：

---------------------------------------------------------------------------

 1 /*
 2 1.多线程共享数据时，会发生线程不安全的情况
 3 2.多线程共享数据必须使用同步
 4  */
 5 
 6 
 7 
 8 public class ThreadDemo4 {
 9 
10     public static void main(String[] args){
11         MyRunnable5 mr5 = new MyRunnable5();
12 
13         Thread t1 = new Thread(mr5);
14         Thread t2 = new Thread(mr5);
15         t1.start();
16         t2.start();
17     }
18 }
19 
20 class  MyRunnable5 implements  Runnable{
21     //两个线程共享一个数据:ticket
22     private int ticket = 10;//售票
23     private Object obj = new Object();
24     public  void run(){
25         for (int i = 0; i < 300; i++) {
26             synchronized (obj) {
27                 if (ticket > 0) {
28                     ticket--;
29                     try {
30                         Thread.sleep(1000);
31                     } catch (InterruptedException e) {
32                         e.printStackTrace();
33                     }
34                     System.out.println("您购买的票剩余" + ticket + "张");
35                 }
36             }
37         }
38     }
39 }

线程安全示例

 1 /*
 2 1.多线程共享数据时，会发生线程不安全的情况
 3 2.多线程共享数据必须使用同步
 4  */
 5 
 6 
 7 public class ThreadDemo4 {
 8 
 9     public static void main(String[] args) {
10         MyRunnable5 mr5 = new MyRunnable5();
11 
12         Thread t1 = new Thread(mr5);
13         Thread t2 = new Thread(mr5);
14         t1.start();
15         t2.start();
16     }
17 }
18 
19 //class  MyRunnable5 implements  Runnable{
20 //    //两个线程共享一个数据:ticket
21 //    private int ticket = 10;//售票
22 //    private Object obj = new Object();//同步锁
23 //    public  void run(){
24 //        for (int i = 0; i < 300; i++) {
25 //            synchronized (this) {
26 //                if (ticket > 0) {
27 //                    ticket--;
28 //                    try {
29 //                        Thread.sleep(1000);
30 //                    } catch (InterruptedException e) {
31 //                        e.printStackTrace();
32 //                    }
33 //                    System.out.println("您购买的票剩余" + ticket + "张");
34 //                }
35 //            }
36 //        }
37 //    }
38 
39 
40 class MyRunnable5 implements Runnable {
41     //两个线程共享一个数据:ticket
42     private int ticket = 10;//售票
43     private Object obj = new Object();//同步锁
44 
45     public void run() {
46         for (int i = 0; i < 300; i++) {
47 //            if (ticket > 0) {
48 //                    synchronized (this) {
49 //                        if (ticket > 0) {
50 //                            ticket--;
51 //                            try {
52 //                                Thread.sleep(1000);
53 //                            } catch (InterruptedException e) {
54 //                                e.printStackTrace();
55 //                            }
56 //                            System.out.println("您购买的票剩余" + ticket + "张");
57 //                        }
58                 method();
59 //            }
60         }
61     }
62 //    同步方法:同步的对象是当前对象(this)
63     private synchronized void method() {
64         if (ticket >0) {
65             ticket--;
66             try {
67                 Thread.sleep(1000);
68             } catch (InterruptedException e) {
69                 e.printStackTrace();
70             }
71             System.out.println("您购买的票剩余" + ticket + "张");
72         }
73     }
74 
75 
76 }

2.同步方法：

  1 /*
  2 1.多线程共享数据时，会发生线程不安全的情况
  3 2.多线程共享数据必须使用同步
  4 3.实现同步的三种方法：
  5     1.使用同步代码块
  6     2.使用同步方法
  7     3.使用Lock(更灵活的代码控制)
  8  */
  9 
 10 
 11 import java.util.concurrent.locks.ReentrantLock;
 12 
 13 public class ThreadDemo4 {
 14 
 15     public static void main(String[] args) {
 16         MyRunnable5 mr5 = new MyRunnable5();
 17 
 18         Thread t1 = new Thread(mr5);
 19         Thread t2 = new Thread(mr5);
 20         t1.start();
 21         t2.start();
 22     }
 23 }
 24 
 25 //class  MyRunnable5 implements  Runnable{
 26 //    //两个线程共享一个数据:ticket
 27 //    private int ticket = 10;//售票
 28 //    private Object obj = new Object();//同步锁
 29 //    public  void run(){
 30 //        for (int i = 0; i < 300; i++) {
 31 //            synchronized (this) {
 32 //                if (ticket > 0) {
 33 //                    ticket--;
 34 //                    try {
 35 //                        Thread.sleep(1000);
 36 //                    } catch (InterruptedException e) {
 37 //                        e.printStackTrace();
 38 //                    }
 39 //                    System.out.println("您购买的票剩余" + ticket + "张");
 40 //                }
 41 //            }
 42 //        }
 43 //    }
 44 
 45 
 46 class MyRunnable5 implements Runnable {
 47     //互斥锁
 48     ReentrantLock lock = new ReentrantLock();
 49     //两个线程共享一个数据:ticket
 50     private int ticket = 10;//售票
 51     private Object obj = new Object();//同步锁
 52 
 53     public void run() {
 54         for (int i = 0; i < 300; i++) {
 55 //            if (ticket > 0) {
 56 //                    synchronized (this) {
 57 //                        if (ticket > 0) {
 58 //                            ticket--;
 59 //                            try {
 60 //                                Thread.sleep(1000);
 61 //                            } catch (InterruptedException e) {
 62 //                                e.printStackTrace();
 63 //                            }
 64 //                            System.out.println("您购买的票剩余" + ticket + "张");
 65 //                        }
 66                 method();
 67 //            }
 68         }
 69     }
 70 
 71 //    同步方法:同步的对象是当前对象(this)
 72     private synchronized void method() {
 73         if (ticket >0) {
 74             ticket--;
 75             try {
 76                 Thread.sleep(1000);
 77             } catch (InterruptedException e) {
 78                 e.printStackTrace();
 79             }
 80             System.out.println("您购买的票剩余" + ticket + "张");
 81         }
 82     }
 83 
 84 //Lock实现同步
 85     private synchronized void method2() {
 86         lock.lock();//锁
 87         try{
 88         if (ticket >0) {
 89             ticket--;
 90             try {
 91                 Thread.sleep(1000);
 92             } catch (InterruptedException e) {
 93                 e.printStackTrace();
 94             }
 95             System.out.println("您购买的票剩余" + ticket + "张");
 96         }
 97         }finally{
 98                 lock.unlock();//释放锁
 99         }
100 
101         }
102 
103 }

3.Lock锁：

 1 package com.vince;
 2 
 3 /**
 4  * Created by vince on 2017/6/5.
 5  * 线程死锁:在一个同步方法中调用了另一个对象的同步方法，可能产生死锁
 6  *
 7  */
 8 public class DeadThreadDemo {
 9 
10     public static void main(String[] args) {
11         new DeadThread();
12     }
13 
14 }
15 
16 //顾客
17 class Customer{
18     public synchronized void say(Waiter w){
19         System.out.println("顾客说：先吃饭再买单！");
20         w.doService();
21     }
22 
23     public synchronized void doService(){
24         System.out.println("同意了,买完单再吃饭！");
25     }
26 }
27 //服务员
28 class Waiter{
29     public synchronized void say(Customer c){
30         System.out.println("服务员说：先买单再吃饭！");
31         c.doService();
32     }
33     public synchronized void doService(){
34         System.out.println("同意了，吃完饭再买单！");
35     }
36 }
37 
38 
39 //死锁线程
40 class DeadThread implements Runnable{
41     Customer c = new Customer();
42     Waiter w = new Waiter();
43     public DeadThread(){
44         new Thread(this).start();
45         w.say(c);
46     }
47     @Override
48     public void run() {
49         c.say(w);
50     }
51 }

DeadThreadDemo.java

  1 package com.vince;
  2 
  3 public class ProducterCustomerDemo {
  4     public static void main(String[] args){
  5         Food food = new Food();
  6         Producter p = new Producter(food);
  7         Customers c = new Customers(food);
  8         Thread t1 = new Thread(p);
  9         Thread t2 = new Thread(c);
 10         t1.start();
 11         t2.start();
 12 
 13     }
 14 }
 15 
 16 /*
 17 消费者
 18  */
 19 class Customers implements Runnable{
 20     private Food food;
 21     public Customers(Food food){
 22         this.food = food;
 23     }
 24 
 25     @Override
 26     public void run() {
 27         for (int i = 0; i < 20; i++) {
 28             food.get();
 29         }
 30     }
 31 }
 32 
 33 
 34 /*
 35 生产者
 36  */
 37 class Producter implements  Runnable{
 38     private Food food;
 39 
 40     public Producter(Food food){
 41         this.food = food;
 42     }
 43 
 44     @Override
 45     public void run() {
 46         for (int i = 0; i < 20; i++) {
 47             if (i%2 ==0){
 48                 food.set("锅包肉","酸甜口味");
 49             }else {
 50                 food.set("佛跳墙","大补");
 51             }
 52         }
 53     }
 54 }
 55 
 56 
 57 class Food{
 58     private String name;
 59     private String desc;
 60     private boolean flag = true;//true表示可以生产，flase表示可以消费
 61     public Food() {
 62 
 63     }
 64 
 65 
 66     /**
 67      * 生产产品
 68      * @return
 69      */
 70 
 71     public synchronized void set(String name,String desc){
 72         this.setName(name);
 73         try {
 74             Thread.sleep(500);
 75         } catch (InterruptedException e) {
 76             e.printStackTrace();
 77         }
 78         this.setDesc(desc);
 79     }
 80 
 81     /**
 82      * 消费产品
 83      */
 84     public synchronized void get(){
 85         try {
 86             Thread.sleep(500);
 87         } catch (InterruptedException e) {
 88             e.printStackTrace();
 89         }
 90         System.out.println(this.getName()+"->"+this.getDesc());
 91     }
 92 
 93 
 94     public String getDesc() {
 95         return desc;
 96     }
 97 
 98     public void setDesc(String desc) {
 99         this.desc = desc;
100     }
101 
102 
103 
104     public String getName() {
105         return name;
106     }
107 
108     public void setName(String name) {
109         this.name = name;
110     }
111 
112     @Override
113     public String toString() {
114         return "Food{" +
115                 "name='" + name + '\'' +
116                 ", desc='" + desc + '\'' +
117                 '}';
118     }
119 
120     public Food(String name,String desc) {
121         this.name = name;
122         this.desc = desc;
123     }
124 }

View Code

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原文地址：https://www.cnblogs.com/juham/p/15657232.html