多线程的创建

方式一：
1．创建一个继承Thread类的子类
2．重写Thread类的run()
3．创建Thread类的子类的对象
4．通过此对象调用start()

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public class ThreadTest {       public static void main(String[] args) {         MyThread t1 = new MyThread();         t1.start();     } }   class MyThread extends Thread{     @Override     public void run() {         for (int i = 1; i < 100; i++) {             if(i%2==0){                 System.out.println(Thread.currentThread().getName()+" "+i);             }         }     } }

　　

　　

方式二：
1.创建一个实现了Runnable接口的类
2.实现类去实现Runnable抽象方法：run()
3，创建实现类的对象
4.将此对象作为参数传递到Thread类的构造器中,创建Thread类的对象
5.通过Thread类的对象调用start()

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public class Window implements Runnable {     private int ticket = 100;       @Override     public void run() {         while (true) {             if (ticket > 0) {                 try {                     Thread.sleep(100);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }                 System.out.println(Thread.currentThread().getName() + "***" + ticket);                 ticket--;             } else {                 break;             }         }     } }   class WindowTest {     public static void main(String[] args) {         Window w = new Window();         Thread t1 = new Thread(w);         Thread t2 = new Thread(w);         Thread t3 = new Thread(w);           t1.setName("线程1");         t2.setName("线程2");         t3.setName("线程3");           t1.start();         t2.start();         t3.start();     } }

　　

 

 

方式三：实现Callable接口
1.创建一个实现Callable接口的实现类
2.实现call方法，将此线程需要执行的操作声明在call()中。
3.创建Callable接口实现类的对象
4.将此Callable接口实现类的对象作为参数传递到FutureTask构造器中，创建FutureTask的对象
5.将FutureTask的对象作为参数传递到Thread类的构造器中，创建Thread对象，并调用start()
6.获取Callable中call()方法返回值

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public class CallableTest {     public static void main(String[] args) {         NumThread numThread = new NumThread();         FutureTask futureTask = new FutureTask(numThread);         Thread t1 = new Thread(futureTask);         t1.start();           try {             //get()返回值即为FutureTask构造器参数Callable实现类重写的call()的返回值             Object sum = futureTask.get();             System.out.println(sum);         } catch (InterruptedException e) {             e.printStackTrace();         } catch (ExecutionException e) {             e.printStackTrace();         }     } }   class NumThread implements Callable{       @Override     public Object call() throws Exception {         int sum = 0;         for (int i = 1; i <= 100; i++) {             sum += i;         }         return sum;     } }

 

使用泛型

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public class CallableTest {     public static void main(String[] args) {         NumThread numThread = new NumThread();         FutureTask<Integer> futureTask = new FutureTask<>(numThread);         Thread t1 = new Thread(futureTask);         t1.start();           try {             //get()返回值即为FutureTask构造器参数Callable实现类重写的call()的返回值             Integer sum = futureTask.get();             System.out.println(sum);         } catch (InterruptedException e) {             e.printStackTrace();         } catch (ExecutionException e) {             e.printStackTrace();         }       }     }   class NumThread implements Callable<Integer>{       @Override     public Integer call() throws Exception {         int sum = 0;         for (int i = 1; i <= 100; i++) {             sum += i;         }         return sum;     } }

　　

 

 方式四：线程池

public class ThreadPool {
    public static void main(String[] args) {
　　　　　//1.提供指定线程数量的线程池
        ExecutorService executorService = Executors.newFixedThreadPool(10);
　　　　　//2.执行指定的线程的操作，需要提供实现Runnable接口或Callable接口实现类的对象
        executorService.execute(new NumberThread());//适用于Runnable
        executorService.execute(new NumberThread2());//适用于Runnable
        //executorService.submit(Callable callable);//适用于Callable
        //关闭连接池
        executorService.shutdown();
    }
}

class NumberThread implements Runnable{

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            if(i%2==0){
                System.out.println(Thread.currentThread().getName()+":"+i);
            }
        }
    }
}

class NumberThread2 implements Runnable{

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            if(i%2!=0){
                System.out.println(Thread.currentThread().getName()+":"+i);
            }
        }
    }
}