To permit the JSP page to access the data, the servlet needs to use setAttribute to store the data in one of the standard locations: the HttpServletRequest, the HttpSession, or the ServletContext. Objects in these locations are known as “scoped varia…

墙外通道:http://thinkiii.blogspot.com/2014/05/a-brief-introduction-to-per-cpu.html per-cpu variables are widely used in Linux kernel such as per-cpu counters, per-cpu cache. The advantages of per-cpu variables are obvious: for a per-cpu data, we do not n…

C# 7 out variables, tuples & other new features C# 7 is available on new Visual Studio 2017 and comes with some new features. I wouldn’t call them ‘revolutionary’ features, but they add on the language very well and some of them can be very helpful.…

google 搜索 java server page http://www.oracle.com/technetwork/java/javaee/jsp/index.html http://docs.oracle.com/javaee/5/tutorial/doc/bnagx.html 5.  JavaServer Pages Technology 6.  JavaServer Pages Documents 7.  JavaServer Pages Standard Tag Library 8…

In the initial article of this series, you got your first look at JSTL. We described the use of its expression language (EL) to access data and operate on it. As you learned, the EL is used to assign dynamic values to the attributes of JSTL custom ta…

1.lambada的存在来由 匿名类的一个问题是,如果匿名类的实现非常简单,例如只包含一个方法的接口,那么匿名类的语法可能看起来不实用且不清楚.在这些情况下,您通常会尝试将功能作为参数传递给另一个方法,例如当有人单击按钮时应采取的操作.Lambda表达式使您可以执行此操作,将功能视为方法参数,或将代码视为数据. 单 interface 单method public interface Predicate<T> { /** * Evaluates this predicate on the gi…

转载自:https://veerasundar.com/blog/2010/11/java-thread-local-how-to-use-and-code-sample/ Thread Local is an interesting and useful concept, yet most of the Java developers are not aware of how to use that. In this post, I’ll explain what is Thread Loca…

Atomic Access In programming, an atomic action is one that effectively happens all at once. An atomic action cannot stop in the middle: it either happens completely, or it doesn't happen at all. No side effects of an atomic action are visible until t…

In the Java community there's been a rush of lightweight containers that help to assemble components from different projects into a cohesive application. Underlying these containers is a common pattern to how they perform the wiring, a concept they r…

Do you need to use JUnit in your testing processes? To answer this question, let's take a look first at unit testing. Unit testing is the lowest resolution of testing in the software testing lifecycle. When you run unit tests, you need to take the sm…

这一章想讲一下Spark的缓存是如何实现的.这个persist方法是在RDD里面的,所以我们直接打开RDD这个类. def persist(newLevel: StorageLevel): this.type = { // StorageLevel不能随意更改 if (storageLevel != StorageLevel.NONE && newLevel != storageLevel) { throw new UnsupportedOperationException("C…

 https://ci.apache.org/projects/flink/flink-docs-release-0.10/apis/programming_guide.html   Example Program 编程的风格和spark很类似, ExecutionEnvironment  -- SparkContext DataSet – RDD Transformations 这里用Java的接口,所以传入function需要用FlatMapFunction类对象   public clas…

Inversion of Control Containers and the Dependency Injection pattern --Martin Fowler 本文内容 Component and Service(组件和服务) A Naive Example(一个超级简单的例子) Inversion of Control(控制反转) Forms of Dependency Injection(依赖注入的几种形式) Constructor Injection with PicoConta…

http://docs.oracle.com/javase/tutorial/essential/concurrency/index.html Concurrency Computer users take it for granted that their systems can do more than one thing at a time. They assume that they can continue to work in a word processor, while othe…

Models and the ServiceManager In the previous chapter we've learned how to create a "Hello World" Application using zend-mvc. This is a good start, but the application itself doesn't really do anything. In this chapter we will introduce you into…

0.前言     需求是这么来的,搭建了Storm集群进行协同过滤算法的计算性能测试,要求精度在毫秒(ms)级别.局域网内40个虚拟机节点,用 date 命令,精度上和效率上都不可行.所以,就搭建了 NTP 服务器. 1.简介     简单的说就是选择几部主要主机 (Primary server) 调校时间,让这些 Primary Servers 的时间同步之后,再开放网络服务来让 Client 端联机,最后使Client 端调整自己的时间.NTP(Network Time Protocol)就…

Instruments 用户指南 http://cdn.cocimg.com/bbs/attachment/Fid_6/6_24457_90eabb4ed5b3863.pdf 原著:Apple Inc. 翻译:謝業蘭[老狼] 联系:xyl.layne@gmail.com 鸣谢:有米移动广告平台 CocoaChina 社区 Instruments User Guide 目录 INSTRUMENTS用户指南...............................................…

前言 NTP(Network Time Protocol,网络时间协议)是用来使网络中的各个计算机时间同步的一种协议.不管是平时使用的私人计算机还是在工作中搭建的服务器集群.时间的统一性和准确性是十分重要的. 本文以自己公司的NTP配置实践过程为例,过程本身并不复杂,原理部分请參考扩展阅读. 时间同步真的非常重要 更新历史 2015年06月26日 - 初稿 阅读原文 - http://wsgzao.github.io/post/ntp/ 扩展阅读 NTP - http://www.ntp.org…

本文是我翻译自国外技术博客的一篇文章,其中讲述了 UEFI 的一些基本概念和细节. 本文的原始链接位于: https://www.happyassassin.net/2014/01/25/uefi-boot-how-does-that-actually-work-then/ 本人的翻译水平有限,难免多有疏漏.废话不多说,请看正文: 又到 AdamW 的讲课时间了,如果你不想听我的长篇大论,那么请出门右拐. Kamil Paral 说我有 写作癖 ,知道自己的坏习惯也是件好事. 可能你已经在互联网…

Main reference: [1] http://winterbe.com/posts/2014/03/16/java-8-tutorial/ [2] https://plus.google.com/107771575694787223844/posts 1. Add default methods for Interfaces In java 8, Interface could have concrete methods using keyword 'default'. interfac…

翻译自 java8-tutorial 新特性 Default Methods for Interfaces(接口的默认方法) Java 8 使我们能够通过使用 default 关键字将非抽象方法实现添加到接口.这个功能也被称为虚拟扩展方法. 这是我们的第一个例子: interface Formula { double calculate(int a); default double sqrt(int a) { return Math.sqrt(a); } } 除了抽象方法 calculate ,…

马上就要进入2018年了,作为年终的盘点,本文列出了一些2017年的关于Go编程的一些文章,并加上简短的介绍. 文章排名不分先后, 文章也不一定完全按照日期来排列.我按照文章的大致内容分了类,便于查找. 文章主要从golangweekly.gocn每日新闻.medium.reddit.twitter..知名博主的文章搜集而来.如果你发现好的2017年的Go文章没有列出来,欢迎在评论中粘帖出来,我会加入到文章正文中. 本文主要列出的是文章,2017年也涌现出来很多优秀的库和工具,但是不是本文要介绍…

Before starting with best practices tobe followed, it is good to have clear understanding of how memory is managed (allocation, de-allocation). So, let us start with memory management first. Managed Heap and Garbage Collection Overview Memory Allocat…

https://blog.golang.org/context Introduction In Go servers, each incoming request is handled in its own goroutine. Request handlers often start additional goroutines to access backends such as databases and RPC services. The set of goroutines working…

https://martinfowler.com/articles/injection.html One of the entertaining things about the enterprise Java world is the huge amount of activity in building alternatives to the mainstream J2EE technologies, much of it happening in open source. A lot of…

delphi 泛型 System.Generics.Collections.pas TList<T> http://docwiki.embarcadero.com/Libraries/Berlin/en/System.Generics.Collections.TListhttp://docwiki.embarcadero.com/CodeExamples/Berlin/en/Generics_Collections_TList_(Delphi)http://docwiki.embarcader…

http://wiki.nginx.org/HttpLuaModule#Directives Name ngx_lua - Embed the power of Lua into Nginx This module is not distributed with the Nginx source. See the installation instructions. Status This module is under active development and is production…

* What's new in version 2.8, 2015-06-17 - SystemTap has improved support for probing golang programs. Work has been  done to be able to handle DWARF information, reporting file names, line  numbers, and column numbers, and tolerance of odd characters…

Inversion of Control Containers and the Dependency Injection pattern In the Java community there's been a rush of lightweight containers that help to assemble components from different projects into a cohesive application. Underlying these containers…

这是来自ethernut网站的一篇文章,原文链接: http://www.ethernut.de/en/documents/arm-inline-asm.html 另外,据说nut/os是个不错的开源os,对单片机以太网开发感兴趣的可以留意一下. 对gcc内联汇编讲解的资料很多,主要也是基于x86架构的,讲解arm的不多.而且,这篇文章对clobber list部分讲得很仔细,包括其他文章很少讲明白的"cc",所以我就果断把它收藏了. ARM GCC Inline Assembler…