java  线程详解及线程与进程的区别

public class Thread02 implements Runnable {
 
  public static void main(String[] args) {
    Runnable r = new <strong>Thread02</strong>();
    Thread t1 = new Thread(<strong>r</strong>, "t1");
    /** 
     *   Thread源码
     *   public Thread(Runnable target, String name) {
          init(null, target, name, 0);
             }
     */
    Thread t2 = new Thread(r, "t2");
    t1.start(); // 启动线程t1，处于就绪状态，等待cpu
    t2.start(); // 启动线程t2，处于就绪状态，等待cpu
    t1.run(); // 主线程main调用对象t1的run方法
  }
 
  public void run() {
    System.out.println("thread's name is "
        + Thread.currentThread().getName());
  }
 
}

thread's name is t1
thread's name is main
thread's name is t2

public class Thread03 extends Thread {
 
  public static void main(String[] args) {
    Thread03 t1 = new <strong>Thread03</strong>();   //不注意的情况下写成了Thread t1=new Thread()  注：Thread03此时就是一个线程了
    t1.start();
  }
 
  public void run() {
    System.out.println("thread's name is "
        + Thread.currentThread().getName());
  }
}

public class Thread01 {
  public static void main(String[] args) {

    Thread thread=new Thread();
    thread.start();//真正起作用 的是run()
    /**而Thread中的run
     * public void run() {
      if (target != null) {
        target.run();
      }
      }
      所以自己创建的线程要重写run方法，把要执行的内容放到run()中，所以要实现接口或继承进而产生子类
     */
    
    //创建线程的方式1 thread子类方式（继承）
    Thread thread1=new Thread(){
      public void run() {
        while(true){
          try {
            Thread.sleep(500);//休息500毫秒
          } catch (InterruptedException e) {
            e.printStackTrace();
          }
          //Thread.currentThread()得到当前线程
          System.out.println("线程1的名字是 "+Thread.currentThread().getName());
        }
      }
    };
//    thread1.start(); //不写  线程无法启动
    
    
    //创建线程的方式2 runnable方式（实现） 推荐使用 
    Thread thread2=new Thread(new Runnable(){

      public void run() {

        while(true){
          try {
            Thread.sleep(300);
          } catch (InterruptedException e) {
            e.printStackTrace();
          }
          System.out.println("thread2'name is "+Thread.currentThread().getName());
          
        }
      }});
//    thread2.start();
    
    //执行的是thread
    new Thread(new Runnable(){
      public void run() {
        System.out.println("runnable "+Thread.currentThread().getName());
      }}){
      public void run() { //子类中的run方法覆盖父类中的run方法，这样就不会执行runnable
        System.out.println("thread "+Thread.currentThread().getName());
      }
    }.start();
  }
  /***
   * 在单个cpu中执行多线程很有可能降低执行效率而不是提高 一个人在不同地方做同一件事情
   */
}