callable

Java: ExecutorService with Callables: invokeAll() and future.get() - results in correct order?

你说的曾经没有我的故事 提交于 2019-12-07 23:13:58
问题 Im using the ExecutorService in Java to invoke Threads with invokeAll() . After, I get the result set with future.get() . Its really important that I receive the results in the same order I created the threads. Here is a snippet: try { final List threads = new ArrayList(); // create threads for (String name : collection) { final CallObject object = new CallObject(name); threads.add(object); } // start all Threads results = pool.invokeAll(threads, 3, TimeUnit.SECONDS); for (Future<String>

What is callable in Java?

Deadly 提交于 2019-12-07 01:52:39
问题 The title pretty much sums it. I want to know the concept and idea of callable . I have read a question here on difference between callable and runnable. but no one show code and give detail what a callable is. I don't want to know the difference between them. I want to know , What is a callable ? When to use them and how to use them . When they come in action for Android. 回答1: You can check this example: In this example Callable task returns the name of thread executing the task after one

Unit test succeeds in debug mode but fails when running it normally

谁说胖子不能爱 提交于 2019-12-05 01:59:37
Why does my unit test succeed in debug mode but fail when running it normally? public class ExecutorServiceTest extends MockitoTestCase{ private int numThreads; private ExecutorService pool; private volatile boolean interruptedBitSet; @Override public void setUp() { numThreads = 5; pool = Executors.newFixedThreadPool(numThreads); } class TaskChecksForInterruptedBit implements Callable<String> { @Override public String call() throws Exception { interruptedBitSet = false; while (!Thread.currentThread().isInterrupted()) { } interruptedBitSet = Thread.currentThread().isInterrupted(); return "blah"

How to better use ExecutorService in multithreading environment?

a 夏天 提交于 2019-12-05 01:29:36
I need to make a library in which I will have synchronous and asynchronous methods in it. executeSynchronous() - waits until I have a result, returns the result. executeAsynchronous() - returns a Future immediately which can be processed after other things are done, if needed. Core Logic of my Library The customer will use our library and they will call it by passing DataKey builder object. We will then construct a URL by using that DataKey object and make a HTTP client call to that URL by executing it and after we get the response back as a JSON String, we will send that JSON String back to

java多线程编程之Future/FutureTask和Callable

夙愿已清 提交于 2019-12-04 20:25:32
有这样一种场景,用多线程发送数据到某个服务器,需要知道各个线程是否都发送成功,等所有线程都发送完成才能继续下一轮计算和发送。如果用传统的多线程方式,就需要启动多个线程,然后在每个线程中分别发送数据,外部通过某种方式等待各个线程全部都发送完成,再进行后面的计算等流程。这种实现方式的代码会比较臃肿,在java中提供了一种Callable+Future的方法,可以将异步的多线程调用变为同步方式。 Callable 在java的多线程编程中,有Thread和Runnable两种方式来新建线程,其中Runnable封装了一个异步运行的任务,可以认为是一个没有任何参数和返回值的异步方法。Callable接口类似于Runnable,两者都是为那些其实例可能被另一个线程执行的类设计的,不同之处在于: Runnable不会返回结果,并且无法抛出经过检查的异常。而Callable是有返回结果并且可能抛出异常的。 Runnable定义了run方法,而Callable定义了一个不带任何参数的叫做call的方法。 此外,Callable接口的类型参数也是返回值的类型。 public interface Callable { /** * Computes a result, or throws an exception if unable to do so. * * @return computed

invokeAll() is not willing to accept a Collection<Callable<T>>

让人想犯罪 __ 提交于 2019-12-04 03:28:06
I fail to understand why this code won't compile ExecutorService executor = new ScheduledThreadPoolExecutor(threads); class DocFeeder implements Callable<Boolean> {....} ... List<DocFeeder> list = new LinkedList<DocFeeder>(); list.add(new DocFeeder(1)); ... executor.invokeAll(list); The error msg is: The method invokeAll(Collection<Callable<T>>) in the type ExecutorService is not applicable for the arguments (List<DocFeeder>) list is a Collection of DocFeeder , which implements Callable<Boolean> - What is going on?! Just to expand on saua's answer a little... In Java 5, the method was declared

Python static method is not always callable

…衆ロ難τιáo~ 提交于 2019-12-03 17:44:28
问题 While parsing attributes using __dict__, my @staticmethod is not callable. Python 2.7.5 (default, Aug 29 2016, 10:12:21) [GCC 4.8.5 20150623 (Red Hat 4.8.5-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from __future__ import (absolute_import, division, print_function) >>> class C(object): ... @staticmethod ... def foo(): ... for name, val in C.__dict__.items(): ... if name[:2] != '__': ... print(name, callable(val), type(val)) ... >>> C.foo() foo

Callable,Future,FutrueTask,CompletionService 详解

醉酒当歌 提交于 2019-12-03 12:15:46
package com.dy.pool; import java.util.concurrent.*; /** * 1: Callable<V> 返回结果并且可能抛出异常的任务。实现者定义了一个不带任何参数的叫做 call 的方法。 Callable 接口类似于 Runnable,两者都是为那些其实例可能被另一个线程执行的类设计的。 但是 Runnable 不会返回结果,并且无法抛出经过检查的异常。 2: Future<V> 表示异步计算的结果 Future 表示异步计算的结果。它提供了检查计算是否完成的方法,以等待计算的完成,并获取计算的结果。 3: CompletionService<V> 将生产新的异步任务与使用已完成任务的结果分离开来的服务 , * 生产者 submit 执行的任务。使用者 take 已完成的任务,并按照完成这些任务的顺序处理它们的结果。 * * * 4:FutureTask<V> 可取消的异步计算。实现了RunbaleFuture, * * RunbaleFuture 继承了Future和Runbale,所以FutureTask<V>可以当做一个线程去提交或执行。 * * 返回FutureTask的操作也可以用Future来接受 * * 利用开始和取消计算的方法、查询计算是否完成的方法和获取计算结果的方法,此类提供了对 Future 的基本实现。 * *

Mule ESB中entry-point-resolver的使用(2) Callable Entry Point Resolver

妖精的绣舞 提交于 2019-12-03 10:24:53
Callable Entry Point Resolver 定义的entry point指向实现了org.mule.api.lifecycle.Callable接口的Component类的onCall(MuleEventContext eventContext)方法,Mule ESB默认的Component Entry Point Resolver就是这类resolver。前面的异常日志输出时我们已经使用了这种Entry Point Resolver,这里不再赘述。如果用户Component想获取Mule Context对象或者Mule Message对象,可以使用这种entry point resolver。 Callable Entry Point Resolver的配置如下 <callable-entry-point-resolver/> 来源: oschina 链接: https://my.oschina.net/u/237688/blog/733414

Constructor for callable object in JavaScript [duplicate]

六月ゝ 毕业季﹏ 提交于 2019-12-03 09:28:22
问题 This question already has answers here : Can a JavaScript object have a prototype chain, but also be a function? (6 answers) Closed 5 years ago . How can I make constructor for callable object in JavaScript? I've attempted various ways, like following. The example there is just shortened example of actual object. function CallablePoint(x, y) { function point() { // Complex calculations at this point return point } point.x = x point.y = y return point } This works at first, but the object it