多线程入门01 —— 新线程创建方法

1.直接继承Thread类

• 代码示例

  package com.pbx.lesson01;
  
  /**
   * @author BruceXu
   * @date 2020/9/13
   */
  public class ThreadDemo01 extends Thread {
      public static void main(String[] args) {
          // 创建一个线程对象，并通过start方法开启该线程
          ThreadDemo01 thread = new ThreadDemo01();
          thread.start();
  
          for (int i = 0; i < 20; i++) {
              System.out.println(i + "-->我在学习");
          }
      }
  
      @Override
      public void run() {
          // 线程体需要执行的动作
          for (int i = 0; i < 20; i++) {
              System.out.println(i + "-->我在玩手机");
          }
      }
  }
  

• 执行结果

从结果中可以看到，main线程和子线程在交替执行

• 存在多个线程时，执行那个线程完全取决于CPU

2.实现runnable接口

• 代码示例

  package com.pbx.lesson01;
  
  /**
   * @author BruceXu
   * @date 2020/9/13
   */
  public class ThreadDemo02 implements Runnable {
      @Override
      public void run() {
          for (int i = 0; i < 20; i++) {
              System.out.println(i+"-->我在玩手机");
          }
      }
  
      public static void main(String[] args) {
  
          new Thread(new ThreadDemo02()).start();
  
          for (int i = 0; i < 20; i++) {
              System.out.println(i + "-->我在学习");
          }
      }
  
  }
  

• 执行结果

3.实现callable接口

• 代码示例

  package com.pbx.lesson01;
  
  import java.util.concurrent.*;
  
  /**
   * @author BruceXu
   * @date 2020/9/13
   */
  public class ThreadDemo03 implements Callable<String> {
  
      private final String name;
  
      public ThreadDemo03(String name) {
          this.name = name;
      }
  
      public static void main(String[] args) throws ExecutionException, InterruptedException {
  
          ThreadDemo03 t1 = new ThreadDemo03("张三");
          ThreadDemo03 t2 = new ThreadDemo03("李四");
          ThreadDemo03 t3 = new ThreadDemo03("王五");
  
          // 1.创建执行服务
          ExecutorService service = Executors.newFixedThreadPool(3);
  
          // 2.提交执行
          Future<String> r1 = service.submit(t1);
          Future<String> r2 = service.submit(t2);
          Future<String> r3 = service.submit(t3);
  
          // 3.获取结果
          System.out.println(r1.get());
          System.out.println(r2.get());
          System.out.println(r3.get());
  
          // 4.关闭服务
          service.shutdown();
  
      }
  
      @Override
      public String call() throws Exception {
          for (int i = 0; i < 10; i++) {
              System.out.println(name + ":" + i + "-->在学习");
          }
          return name + "在学习";
      }
  }
  

• 执行结果