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:
