Android線程池(一)——Executors(線程池)以及FutureTask使用示例

package cc.vv;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;
import android.os.Bundle;
import android.app.Activity;
/**
 * Demo描述:
 * 線程池使用示例
 * 
 * 創建線程池的主要方式:
 * newCachedThreadPool()
 * newFixedThreadPool(int i)
 * newScheduledThreadPool(int i)
 * SingleThreadExecutor()
 * 
 * Demo內容:
 * 1 newFixedThreadPool(int i)和SingleThreadExecutor()的使用
 * 2 線程池(Executors)和FutureTask的結合使用
 * 
 * 參考資料:
 * 1 http://blog.csdn.net/ns_code/article/details/17465497
 * 2 http://blog.csdn.net/tounaobun/article/details/8586675
 * 3 http://blog.csdn.net/linghu_java/article/details/17123057
 * 4 http://blog.csdn.net/andycpp/article/details/8902655
 *   Thank you very much
 */
public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		//testExecutors1();
		//testExecutors2();
		testExecutors3();
	}

	////////////////////////////////////////////////////////////////////////
	/**
	 * newFixedThreadPool的使用
	 * 1 創立一個線程池,該線程池中有5個線程
	 * 2 將15個RunnableImpl對象放入線程中執行
	 *  可以看到這15個RunnableImpl在5個線程中調用
	 * 
	 */
	private void testExecutors1(){
		Executor executor=Executors.newFixedThreadPool(5);
		RunnableImpl1 runnableImpl1=null;
		for (int i = 0; i < 15; i++) {
			runnableImpl1=new RunnableImpl1();
			executor.execute(runnableImpl1);
		}
	}
	
	private class RunnableImpl1 implements Runnable{
		@Override
		public void run() {
			System.out.println("線程名字:"+Thread.currentThread().getName());
		}
		
	}
   ////////////////////////////////////////////////////////////////////////
	
	
	
	
   ////////////////////////////////////////////////////////////////////////
	/**
	 * newSingleThreadExecutor()的使用
	 * 創建一個只包含了一個線程的線程池,它只會用該唯一工作線程來執行任務.
	 * 從而保證所有任務按照指定順序(FIFO)執行.
	 * 
	 * 該特點還是很具有實際意義的.
	 * 
	 */
	private void testExecutors2(){
		Executor executor=Executors.newSingleThreadExecutor();
		RunnableImpl2 runnableImpl2=null;
		for (int i = 0; i < 15; i++) {
			runnableImpl2=new RunnableImpl2(""+i);
			executor.execute(runnableImpl2);
		}
	}
	
	private class RunnableImpl2 implements Runnable{
		private String name;
		private RunnableImpl2(String name){
			this.name=name;
		}
		@Override
		public void run() {
			System.out.println("線程名字:"+name);
		}
		
	}
	
   ////////////////////////////////////////////////////////////////////////
	
	
	
	
	////////////////////////////////////////////////////////////////////////
	/**
	 * 線程池(Executors)和FutureTask的結合使用
	 */
	private void testExecutors3() {
		ExecutorService executorService = Executors.newFixedThreadPool(5);
		ArrayList futureTaskArrayList = new ArrayList();
		CallableImpl callableImpl = null;
		FutureTask futureTask = null;
		for (int i = 0; i < 10; i++) {
			callableImpl = new CallableImpl();
			futureTask = new FutureTask(callableImpl);
			//執行FutureTask
			executorService.execute(futureTask);
			//將每個FutureTask保存到集合中,便於之後獲取其對應的結果.
			futureTaskArrayList.add(futureTask);
		}

		//遍歷集合,獲取每個FutureTask執行的結果
		try {
			for (Iterator iterator = futureTaskArrayList.iterator(); iterator.hasNext();) {
				FutureTask ft = (FutureTask) iterator.next();
				//直到該FutureTask計算完成,才會調用到ft.get()
				while (!ft.isDone());
				System.out.println("-----> 返回結果:" + ft.get());
			}
		} catch (Exception e) {
			
		}

	}

	// //////////////////////////////////////////////////////////////////////
	
	
	
	
}

CallableImpl如下:

package cc.vv;

import java.util.Random;
import java.util.concurrent.Callable;

public class CallableImpl implements Callable {
	
	public CallableImpl() {}

	@Override
	public Integer call() throws Exception {
		int result=new Random().nextInt(100);
		System.out.println(""+Thread.currentThread().getName());
		return Integer.valueOf(result);
	}

}

main.xml如下: