java線程創建方式（4種）

1.  繼承Thread類
2.  實現Runnable接口
3.  實現Callable接口，使用FutureTask方式
4.  使用線程池

 1. 繼承Thread類

package com.pimee.thread;
/**
 * 繼承Thread創建線程
 * @author Bruce Shaw
 *
 */
public class ThreadTest extends Thread {

	public static void main(String[] args) {
		ThreadTest test = new ThreadTest();
		test.start();
	}

	@Override
	public void run() {
		System.out.println("This is TestThread...");
	}
}

2. 實現Runnable接口

package com.pimee.thread;
/**
 * 實現runnable接口創建線程
 * @author Bruce Shaw
 *
 */
public class RunnableTest implements Runnable {
	private static int test = 10;

	@Override
	public void run() {
		System.out.println("This is RunnableTest...");
	}

	public static void main(String[] args) {
		RunnableTest test = new RunnableTest();
		new Thread(test).start();
	}
}

以上兩種方式實現都比較簡單，缺點很明顯，就是線程執行後沒有返回值。且看下面帶有返回值的實現方式：

3. 實現Callable接口，使用FutureTask方式

package com.pimee.thread;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeoutException;

/**
 * 實現callable接口，基於FutureTask方式實現
 * @author Bruce Shaw
 *
 */
public class CallableTest implements Callable<String> {

	public static void main(String[] args) throws InterruptedException, ExecutionException, TimeoutException {
		CallableTest mc = new CallableTest();
		FutureTask<String> ft = new FutureTask<>(mc);
		Thread thread = new Thread(ft);
		thread.start();
		System.out.println(ft.get());
	}

	@Override
	public String call() throws Exception {
		System.out.println("Callable is running...");
		return "Callable finished and return value...";
	}
}

4. 使用線程池

package com.pimee.thread;

import java.util.concurrent.*;
/**
 * 基於線程池創建
 *
 * @author Bruce Shaw
 *
 */
public class ThreadPoolTest implements Callable<String> {

    public static void main(String[] args) throws InterruptedException, ExecutionException, TimeoutException {
        ExecutorService newCachedThreadPool = Executors.newSingleThreadExecutor();
        Future<String> future = newCachedThreadPool.submit(new CallableTest());
        try {
            System.out.println(future.get());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            newCachedThreadPool.shutdown();
        }
    }

    @Override
    public String call() throws Exception {
        System.out.println("Callable is running...");
        return "Callable finished and return value...";
    }
}

嚴格意義上來說，只是3種實現方式，因爲最後一種方式的實現是池化，可以創建上面Thread、Runnable、Callable的任意一種任務。

代碼已提交於：https://gitee.com/pimee/pm-test/tree/master/pm-thread/src/main/java/com/pimee/thread