項目結構

繼承Thread類

/*
 * Thread類實現了Runnable接口
 */

public class MyThread extends Thread {
    @Override
    public void run() {
        for(int i=0;i<50;i++){
            System.out.println("MyThread子線程 : "+Thread.currentThread().getName()+"~~~"+i);
        }
    }
}

實現Runnable接口

public class MyRunnable implements
 
 Runnable {

    @Override
    public void run() {
        for(int i=0;i<50;i++){
            System.out.println("MyRunnable子線程 : "+Thread.currentThread().getName()+"~~~"+i);
        }
    }

}

實現Callable<T>接口

import java.util.concurrent.Callable;
/*
 * FutureTask<V>類實現了RunnableFuture<V>接口，
 * RunnableFuture<V>接口實現了Runnable接口、Future<V>接口。
 * FutureTask<V>對象的get方法：等待計算完成，然後獲取其結果。
 
 
*/

public class MyCallable implements Callable<Integer> {

    @Override
    public Integer call() throws Exception {
        int sum = 0;
        for(int i=0;i<100;i++){
            sum += i;
            System.out.println("MyCallable子線程中間結果 : "+sum);
        }
        return sum;
    }

}

運行

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


public class Test {

    public static void main(String[] args) throws Exception {
        System.out.println("主線程 : "+Thread.currentThread().getName());
        MyThread thread = new MyThread();
        MyRunnable runnable = new MyRunnable();
        Thread thread2 = new Thread(runnable);
        MyCallable callable = new MyCallable();
        FutureTask<Integer> task = new FutureTask<Integer>(callable);
        Thread thread3 = new Thread(task);
        thread.start();
        thread2.start();
        thread3.start();
        int sum = task.get();
        System.out.println("MyCallable子線程最終結果 : " + sum); // 這段代碼總是最後執行
    }

}

Java的三種多線程