代理设计模式之安卓中的实际应用

/**
 * 管理线程池
 * 
 * @author itcast
 * 
 */
public class ThreadManager {
private ThreadManager() {


}


private static ThreadManager instance = new ThreadManager();
private ThreadPoolProxy longPool;
private ThreadPoolProxy shortPool;


public static ThreadManager getInstance() {
return instance;
}


// 联网比较耗时
// cpu的核数*2+1
public synchronized ThreadPoolProxy createLongPool() {
if (longPool == null) {
longPool = new ThreadPoolProxy(5, 5, 5000L);
}
return longPool;
}
// 操作本地文件
public synchronized ThreadPoolProxy createShortPool() {
if(shortPool==null){
shortPool = new ThreadPoolProxy(3, 3, 5000L);
}
return shortPool;
}


public class ThreadPoolProxy {
private ThreadPoolExecutor pool;
private int corePoolSize;
private int maximumPoolSize;
private long time;


public ThreadPoolProxy(int corePoolSize, int maximumPoolSize, long time) {
this.corePoolSize = corePoolSize;
this.maximumPoolSize = maximumPoolSize;
this.time = time;


}
/**
* 执行任务
* @param runnable
*/
public void execute(Runnable runnable) {
if (pool == null) {
// 创建线程池
/*
* 1. 线程池里面管理多少个线程2. 如果排队满了, 额外的开的线程数3. 如果线程池没有要执行的任务 存活多久4.
* 时间的单位 5 如果 线程池里管理的线程都已经用了,剩下的任务 临时存到LinkedBlockingQueue对象中 排队
*/
pool = new ThreadPoolExecutor(corePoolSize, maximumPoolSize,
time, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>(10));
}
pool.execute(runnable); // 调用线程池 执行异步任务
}
/**
* 取消任务
* @param runnable
*/
public void cancel(Runnable runnable) {
if (pool != null && !pool.isShutdown() && !pool.isTerminated()) {
pool.remove(runnable); // 取消异步任务
}
}
}
}