框架结构
- 任务：Runnable和Callable
- 任务的执行：Executor接口->ExecutorService接口
- ThreadPoolExecutor
- ScheduledThreadPoolExecutor
- 异步计算的结果：Future接口->FutureTask类
ThreadPoolExecutor
代码语言：javascript复制new ThreadPoolExecutor(corePoolSize,maximumPoolSize,keepAliveTime,timeunit,runnableTaskQueue,handler)- corePoolSize: 预热到这个线程大小，不再创建新线程，就要放到runnableTaskQueue里面
- maximumPoolSize：只有runnableTaskQueue满了，才会创建新线程，最大线程数不超过这个值
- runnableTaskQueue： 任务队列
- handler：饱和策略
- AbortPolicy：直接抛弃
通常使用工厂类Executors创建：
1.FixedThreadPool：满足资源管理的需求，适合负载比较重的服务器
代码语言：javascript复制public static ExecutorService newFixedThreadPool(int nThreads)
public static ExecutorService newFixedThreadPool(int nThreads,ThreadFactory threadFactory)源代码：
代码语言：javascript复制public static 2.SingleThreadPool: 满足保证顺序的执行每个任务，并且在任意时间点，不会有多个线程是活动的场景
代码语言：javascript复制public static ExecutorService newSingleThreadPool()
public static ExecutorService newSingleThreadPool(ThreadFactory threadFactory)3.CachedThreadPool:大小无界，适用于很多短期异步的小程序，或者是负载较轻的服务器
代码语言：javascript复制public static ExecutorService newCachedThreadPool()
public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory)ScheduledThreadPoolExecutor
使用工厂类Executors创建 1.ScheduledThreadPoolExecutor:
代码语言：javascript复制public static ExecutorService newScheduledThreadPool(int nThreads)
public static ExecutorService newScheduledThreadPool(int nThreads,ThreadFactory threadFactory)2.SingleThreadScheduledExecutor:
代码语言：javascript复制public static ExecutorService newSingleThreadScheduledExecutor()
public static ExecutorService newSingleThreadScheduledExecutor(ThreadFactory threadFactory)Future接口
当我们把Runnable接口或者Callable接口submit给ThreadPoolExecutor时，会返回一个FutureTask对象，API：
代码语言：javascript复制<T> Future<T> submit(Callable<T> Task)
<T> Future<T> submit(Runnable Task,T result)
Future> submit(Runnable Task)Runnable和Callable接口
Executors提供的：
代码语言：javascript复制public static Callable callable(Runnable task)
public static Callable callable(Runnable task,T Result)
