The creation and use of java multithreading

1. What is a thread?

Thread: It is the smallest unit that the operating system can perform operation scheduling. It is included in the process and is the actual operating unit in the process. A thread refers to a single sequential control flow in a process. Multiple threads can be concurrent in a process, and each thread executes different tasks in parallel.

2. Under what circumstances will threads be used?

Multi-threading is needed when multiple tasks are needed at the same time. For a simple example, when we are executing a thread, the thread may draw a long straight line, it takes a certain amount of time to complete, but the actual situation requires me to draw the first line when the second Article, Article 3. . . Start painting too. This is to use multi-threading. In one sentence: Run multiple tasks at the same time.
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(Single-threaded example: after the first line is drawn, the second line will start)

3. How to create threads?

Create a multi-threaded class (my name: DrawThread.java)
and define the parameters that need to be used

 public DrawThread(int x,int y,Graphics g) {
    
    
   this.x=x;
   this.y=y;
   this.g=g;
 }

2. Pass the class object of DrawThread created in the main interface

DrawThread dThread=new DrawThread(x,y,g);//创建多线程类的的对象
dThread.start();//一定要用这个对象去启动线程！！

3. Rewrite the run function in DrawThread


 public void run(){
    
    
  Color pink=new Color(255,192,203);
  g.setColor(pink);
  for (int i = 0; i < 600; i++) {
    
    
   g.fillOval(x+i, y, 80, 80);
       try {
    
    //睡眠10ms，用来减慢画的速度
        Thread.sleep(10);//这一句是加进去得
       } catch (Exception e2) {
    
    
        // TODO: handle exception
       }
 
 }

4. Effect display

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