java自带四种线程池:
- FixedThreadPool
- SingleThreadExecutor
- CachedThreadPool
- ScheduledThreadPool
- submit方法与execute方法的区别 submit方法调用execute方法,submit方法有返回值,execute方法没有返回值
- offer和add方法区别 add方法比offer方法多一个异常,add方法不会返回false
abortPolicy
callerRunsPolicy
discardPolicy
discardOldestPolicy