thread creation

There are several ways to write code that a thread executes when it runs:

• Create an instance of the Thread subclass and override the run method
• Create a class that implements the Runnable interface and pass it to the Thread class
• lambda expression

1. Create a subclass of Thread

    public class MyThread extends Thread {
        public void run() {
        	System.out.println("Hello new thread");
        }
    }
   

   A thread execution above can be created by:

    Mythread myThread = new MyThread();
    myThread.start();
   

   After the start() method is called, a new thread is started, the parent thread returns to continue execution, and the run() function defined above is executed in the child thread

2. Implement the runnable interface

   Create a new instance object that implements the Runnable interface as the input parameter of the Thread class constructor:

    Runnable myRunnable = new Runnable() {
        public void run() {
    	    System.out.println("Hello Runnable");
        }
    }
    Thread thread = new Thread(myRunnable);
    thread.start();
   

   More commonly used is to start a thread directly using an anonymous inner class

    new Thread(new Runnable() {
        [@override](https://my.oschina.net/u/1162528)
        public void run() {
    	    System.out.println("Hello new thread");
        }
    }).start();
   

3. After Java 1.8, you can use lambda expressions to simplify the operation

    new Thread( () -> System.our.println("Hello Lambda")).start();
   

4. Use Executor to manage Thread objects

   Often a single Executor is used to create and manage all tasks in the system, and a call to the shutdown() method prevents new tasks from being submitted to this Executor.

    public class CachedThreadPool {
        public static void main(String[] args) {
    	    ExecutorService exec = Executors.newCachedThreadPool();
    	    for (int i = 0; i < 5; i++)
    		    exec.execute(new Runnable() {
    		    	  [@override](https://my.oschina.net/u/1162528)
    			    public void run() {
    			    System.out.println("")
    			}
    		}；
    	exec.shutdown();
    }
   

   }