 package com.xiaostudy.thread;
  
  /**
   * @desc 第一種開啟線程的方式
  * @author xiaostudy
   *
   */
  public class Demo1_Thread extends Thread {
  
     public void run() {
         for (int i = 0; i < 10; i++) {
             System.out.println(i + " run()...");
         }
     }
 
   public static void main(String[] args) {
         Demo1_Thread demo = new Demo1_Thread();
         demo.start();
         for (int i = 0; i < 10; i++) {
             System.out.println(i + " main()...");1         }
     }
 
 }

上面這里就是當(dāng)前類的一個(gè)線程和main線程一起運(yùn)行

2、實(shí)現(xiàn)Runnable接口，然后新建當(dāng)前類對(duì)象，接著新建Thread對(duì)象時(shí)把當(dāng)前類對(duì)象傳進(jìn)去，最后運(yùn)行Thread對(duì)象的start()方法

 package com.xiaostudy.thread;
  
  /**
   * @desc 第二種開啟線程的方式
   * @author xiaostudy
   *
   */
  public class Demo2_Thread implements Runnable {
  
     public void run() {
         for (int i = 0; i < 10; i++) {
             System.out.println(i + " run()...");
         }
     }
 
     public static void main(String[] args) {
         Demo2_Thread demo = new Demo2_Thread();
         Thread thread = new Thread(demo);
         thread.start();     
         for (int i = 0; i < 10; i++) {
            System.out.println(i + " main()...");
         }
     }
 
 }

分析：從Thread的有參構(gòu)造方法進(jìn)去

當(dāng)前類傳進(jìn)去，進(jìn)入到Thread的init()方法

再跟進(jìn)去

下面截圖問題，分開兩個(gè)，看行號(hào)。就把當(dāng)前類賦值給了Thread的target屬性

再回過頭來(lái)看Thread對(duì)象的run()方法，因?yàn)楫?dāng)Thread對(duì)象的start()方法調(diào)用時(shí)，是執(zhí)行Thread對(duì)象的run()方法（這里就不深入分析）

這里的target的值就是當(dāng)前類對(duì)象，所以最后還是執(zhí)行了當(dāng)前類對(duì)象的run()方法

3、實(shí)現(xiàn)Callable接口，新建當(dāng)前類對(duì)象，在新建FutureTask類對(duì)象時(shí)傳入當(dāng)前類對(duì)象，接著新建Thread類對(duì)象時(shí)傳入FutureTask類對(duì)象，最后運(yùn)行Thread對(duì)象的start()方法

package com.xiaostudy.thread;

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

/**
 * @desc 第三種開啟線程的方式
 * @author xiaostudy
 *
 */
public class Demo3_Thread implements Callable {

    public static void main(String[] args) {
        Callable callable = new Demo3_Thread();
        FutureTask futureTask = new FutureTask(callable);
        Thread thread = new Thread(futureTask);
        thread.start();
        for (int i = 0; i < 10; i++) {
            System.out.println(i + " main()...");
        }
    }

    public Object call() throws Exception {
        for (int i = 0; i < 10; i++) {
            System.out.println(i + " call()...");
        }
        return null;
    }

}

Demo3_Thread.java