002 Thread creation

I. Overview

There are two ways to create a thread, but in fact there is only one way.

[1] Inherit Thread and override the run() method.

[2] Implement the Runnable interface and override the run() method.

We can actually implement the Runnable method as a strategy pattern implementation.

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2. Inherit Thread to create a thread

@Test
    public void test() {
        new Thread() {
            public void run() {
                for(;;)
                    System.out.println("running....");
            };
        }.start();
    }

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3. Implement the Runnable interface

@Test
    public void test2() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                for(;;)
                    System.out.println("running ... ");
            }
        }).start();
    }

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4. Comparison

In fact, there is only one way to create a thread, that is to create a Thread object and then start the thread, otherwise the thread in the new state is not actually a real thread.

　　So, what about the Runnable interface?

　　　　The run() method is just a thread logic unit.

　　We can understand it as an application of the strategy pattern, and the threads we create are executing different algorithms (strategies).

　　Note: The startup of a thread needs to call the JNI code, that is, after the JVM allocates thread resources, it can be regarded as a thread.