[thread communication]

The roughest “ File sharing ” signal communication

Through file sharing

package com.fly.threadDome;

import java.nio.file.Files;
import java.nio.file.Paths;

/** * @Title:  Thread communication  * @Author: Fly * @Date: 2020/8/30 - 13:50 * @Description: */
public class ThreadDome {
    
    public static void main(String[] args) {
    
        // Threads 1： Write data 
        new Thread(()->{
    
            try{
    
                while (true){
    
                    Files.write(Paths.get("E:\\TestFile.txt"),
                            (" current time "+String.valueOf(System.currentTimeMillis())).getBytes());
                    Thread.sleep(1000L);
                }
            }catch (Exception e){
    
                e.printStackTrace();
            }
        }).start();

        // Threads 2： Reading data 
        new Thread(()->{
    
            try{
    
                while (true){
    
                    Thread.sleep(1000l);
                    byte[] allBytes =Files.readAllBytes(Paths.get("E:\\TestFile.txt"));
                    System.out.println(new String(allBytes));
                }
            }catch (Exception e){
    
                e.printStackTrace();
            }
        }).start();
    }
}

file TestFile.txt Record the last time

Console while(true) Read the contents of the latest file every time

Variable sharing

Use the variable area of memory

    public static String content=" empty ";
    private static void variableThread() {
    
        // Threads 1： Write data 
        new Thread(()->{
    
            try{
    
                while (true){
    
                    content=(" current time :"+String.valueOf(System.currentTimeMillis()));
                    Thread.sleep(1000L);
                }
            }catch (Exception e){
    
                e.printStackTrace();
            }
        }).start();

        // Threads 2： Reading data 
        new Thread(()->{
    
            try{
    
                while (true){
    
                    Thread.sleep(1000l);
                    System.out.println(content);
                }
            }catch (Exception e){
    
                e.printStackTrace();
            }
        }).start();
    }

Thread collaboration -JDK API

A trite topic , Don't post code here

• JDK For the scenarios that need multi-threaded cooperation to complete a task , The corresponding API Support
• A typical scenario for multithreading collaboration is ： producer - Consumer model .（ Thread blocking 、 Thread wake up ）
• Example ： Threads A Go to buy steamed buns , No bun , No more execution . Threads B To produce a bun , Notification thread A Carry on