在面試中老有面試官問這個問題，個人覺得這個問題問的沒有技術，一個死記硬背就能回答的很好。但是更深的回答是什麼了，那就是直接回答原始碼吧。 thread類實現了runnable 介面 ，Runnable就是一個藉口 ，只能我們去實現了才能用 對吧，不管是普通類 還是匿名內部類 ，最大的區別是我們的自己的實現類 沒有辦法啟動執行緒，還是要藉助於thread

結果就出現了執行緒的實現方法

package test8;

/**
 * 方式一
 * @author suifeng
 *
 */
class myThread extends Thread{
	
	@Override
	public void run() {
		// TODO Auto-generated method stub
		System.out.println(Thread.currentThread());
	}
}

/**
 * 方式二
 * @author suifeng
 *
 */
class myRunable implements Runnable{
	
	@Override
	public void run() {
		// TODO Auto-generated method stub
		System.out.println(Thread.currentThread());
	}
}
public class DT {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		new myThread().start();

		new Thread(new myRunable()).start();

		
	}

}
 

public synchronized void start() {
        /**
         * This method is not invoked for the main method thread or "system"
         * group threads created/set up by the VM. Any new functionality added
         * to this method in the future may have to also be added to the VM.
         *
         * A zero status value corresponds to state "NEW".
         */
        if (threadStatus != 0)
            throw new IllegalThreadStateException();

        /* Notify the group that this thread is about to be started
         * so that it can be added to the group's list of threads
         * and the group's unstarted count can be decremented. */
        group.add(this);

        boolean started = false;
        try {
            start0();
            started = true;
        } finally {
            try {
                if (!started) {
                    group.threadStartFailed(this);
                }
            } catch (Throwable ignore) {
                /* do nothing. If start0 threw a Throwable then
                  it will be passed up the call stack */
            }
        }
    }
 

 private native void start0();

package test8;

import java.lang.Thread.State;
import java.lang.Thread.UncaughtExceptionHandler;

interface Work {

	void work();
}

/**
 * 裝飾模式  
 * @author suifeng
 *
 */
class Mthread implements Runnable {
	Thread dt;
	Work w;

	public Mthread(Work w) {
		dt = new Thread(this);
		this.w = w;
		dt.start();
	}

	public int hashCode() {
		return dt.hashCode();
	}

	public boolean equals(Object obj) {
		return dt.equals(obj);
	}

	public void start() {
		dt.start();
	}

	// ...
	public void run() {
		w.work();
	}

	public final void stop() {
		dt.stop();
	}

	public final void stop(Throwable obj) {
		dt.stop(obj);
	}

	public void interrupt() {
		dt.interrupt();
	}

	public boolean isInterrupted() {
		return dt.isInterrupted();
	}

	public void destroy() {
		dt.destroy();
	}

	public final boolean isAlive() {
		return dt.isAlive();
	}

	public final void suspend() {
		dt.suspend();
	}

	public final void resume() {
		dt.resume();
	}

	public final void setPriority(int newPriority) {
		dt.setPriority(newPriority);
	}

	public final int getPriority() {
		return dt.getPriority();
	}

	public final void setName(String name) {
		dt.setName(name);
	}

	public final String getName() {
		return dt.getName();
	}

	public final ThreadGroup getThreadGroup() {
		return dt.getThreadGroup();
	}

	public int countStackFrames() {
		return dt.countStackFrames();
	}

	public final void join(long millis) throws InterruptedException {
		dt.join(millis);
	}

	public final void join(long millis, int nanos) throws InterruptedException {
		dt.join(millis, nanos);
	}

	public final void join() throws InterruptedException {
		dt.join();
	}

	public final void setDaemon(boolean on) {
		dt.setDaemon(on);
	}

	public final boolean isDaemon() {
		return dt.isDaemon();
	}

	public final void checkAccess() {
		dt.checkAccess();
	}

	public String toString() {
		return dt.toString();
	}

	public ClassLoader getContextClassLoader() {
		return dt.getContextClassLoader();
	}

	public void setContextClassLoader(ClassLoader cl) {
		dt.setContextClassLoader(cl);
	}

	public StackTraceElement[] getStackTrace() {
		return dt.getStackTrace();
	}

	public long getId() {
		return dt.getId();
	}

	public State getState() {
		return dt.getState();
	}

	public UncaughtExceptionHandler getUncaughtExceptionHandler() {
		return dt.getUncaughtExceptionHandler();
	}

	public void setUncaughtExceptionHandler(UncaughtExceptionHandler eh) {
		dt.setUncaughtExceptionHandler(eh);
	}
}

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

		new Mthread(new Work() {

			@Override
			public void work() {
		 
				System.out.println(Thread.currentThread());
			}
		});

		new Mthread(new Work() {

			@Override
			public void work() {
				// TODO Auto-generated method stub
				System.out.println(Thread.currentThread());
			}
		});
		
		
		while (Thread.activeCount() > 1) {
			Thread.yield();
		}

	}
}