由于不需要每次处理复杂逻辑耗时操作,比如加载网络并不需要都开启一个新的线程,可以用线程池处理,把线程存起来,用的时候在取出来,在ondestory里去销毁线程,这样就会节省内存
线程池的原理(看看就行):
代码语言:javascript复制public class ThreadPool { int maxCount = 3; AtomicInteger count =new AtomicInteger(0);// 当前开的线程数 count=0 LinkedList<Runnable> runnables = new LinkedList<Runnable>(); public void execute(Runnable runnable) { runnables.add(runnable); if(count.incrementAndGet()<=3){ createThread();// 最大开三个线程 } } private void createThread() { new Thread() { @Override public void run() { super.run(); while (true) { // 取出来一个异步任务 if (runnables.size() > 0) { Runnable remove = runnables.remove(0); //在集合中移除第一个对象 返回值正好是移除的对象 if (remove != null) { remove.run(); } }else{ // 等待状态 wake(); } } } }.start(); }}
线程池的用法:在本项目中新建一个类管理线程池,主要用的就是ThreadPoolExecutor这个类
代码语言:javascript复制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 // 开启线程数一般是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 } } }}