Guava并发（2）——ListenableFuture\FutureCallback\SettableFuture\Futures
ListenableFuture类jdk5之后有了Future这种异步执行的结构ExecutorServiceexecutor=Executors.newCachedThreadPool();Futurefuture=executor.submit(newCallable(){publicIntegercall()throwsException{returnservice.getCount();}