定义: 定义一个工厂类,它可以根据参数的不同生成对应的类的实例:被创建的类的实例通常有相同的父类.因为该工厂方法尝尝是静态的,所以又被称为静态工厂方法(Static Factory Method) 结构图: Factory:工厂类,工厂模式的核心.负责创建所有产品实例的内部逻辑,被外界直接调用,返回抽象类Product. Product:抽象产品类,封装了各种产品的公有方法,利于提高系统的可扩展性. ConcreteProduct:具体产品类,工厂创建目标.继承或实现了抽象产品类的抽象方法,含有

Pattern matching in functional programming languages is a way to break up expressions into individual cases. We are going to go through how to pattern match in PureScript with simple patterns, guards, array patterns and record patterns. greater :: In

一.简单工厂(Simple Factory)模式 Simple Factory 模式根据提供给它的数据,返回几个可能类中的一个类的实例.通常它返回的类都有一个公共的父类和公共的方法. Simple Factory 模式实际上不是 Gof 23个设计模式中的一员. 二. 简单工厂(Simple Factory)模式角色与结构 工厂类角色Creator (LightSimpleFactory):工厂类在客户端的直接控制下(Create方法)创建产品对象. 抽象产品角色Product (Light):

原文地址:CQRS, Task Based UIs, Event Sourcing agh! Many people have been getting confused over what CQRS is. They look at CQRS as being an architecture; it is not. CQRS is a very simple pattern that enables many opportunities for architecture that may ot

Engish version copied from here Why This Document? As editor of the Jargon File and author of a few other well-known documents of similar nature, I often get email requests from enthusiastic network newbies asking (in effect) "how can I learn to be a

多态的应用-面向父类编程 1.对象的编译时类型写成父类 2.方法的返回类型写成父类 3.方法的参数类型写成父类 编译时类型:对象的声明时类型,在于编译期间 运行时类型:new运算符后面的类型 编译时类型决定了对象的访问能力 运行时类型决定了对象真正的行为能力--------------------------------------------------------------------------------将打印图形面积和周长的业务方法封装到一个业务类当中ShapeBiz.java //

Regular expressions are a language of their own. When you learn a new programming language, they're this little sub-language that makes no sense at first glance. Many times you have to read another tutorial, article, or book just to understand the "s

Robot Framework -- A generic test automation framework Version: 3.0 (Python 3.4.0 on win32) Usage: robot [options] data_sources or: python -m robot [options] data_sources or: python path/to/robot [options] data_sources or: java -jar robotframework.ja

原文: https://code.google.com/p/googlemock/wiki/CookBook Creating Mock Classes Mocking Private or Protected Methods Mocking Overloaded Methods Mocking Class Templates Mocking Nonvirtual Methods Mocking Free Functions The Nice, the Strict, and the Naggy

最近用BDB写点东西,写了挺多个测试工程.列下表,也理清楚最近的思路 1.测试BDB程序,包括打开增加记录,查询记录,获取所有记录.将数据转存mysql 程序的不足,增加记录仅仅只有key和value,查询记录仅仅是简单的根据key或者同时制定key和value来查,只获取所有记录,没有获取部分记录,转存mysql消耗比较大 2.mysql和BDB插入和选择数据比较. 在java虚拟机内存相同的条件下,mysql插入数据量比较大时会报内存溢出,BDB 插入数据的量可以比mysql大.而且速度也快

一.stanford parser是什么? stanford parser是stanford nlp小组提供的一系列工具之一,能够用来完成语法分析任务.支持英文.中文.德文.法文.阿拉伯文等多种语言. 可以从这里(http://nlp.stanford.edu/software/lex-parser.shtml#Download)下载编译好的jar包.源码.javadoc等等. http://nlp.stanford.edu/software/parser-faq.shtml是FAQ,看一下FA

Problem: Description: Count the number of prime numbers less than a non-negative number, n. Analysis: The idea to test if a number is prime. Reference: https://en.wikipedia.org/wiki/Prime_number Prime number is an important category of problems. It i

redis提供了rate limit demo 如下所示: INCR key Available since 1.0.0. Time complexity: O(1) Increments the number stored at key by one. If the key does not exist, it is set to 0 before performing the operation. An error is returned if the key contains a valu

参考:Function and Operator Reference Name Description ABS() Return the absolute value ACOS() Return the arc cosine ADDDATE() Add time values (intervals) to a date value ADDTIME() Add time AES_DECRYPT() Decrypt using AES AES_ENCRYPT() Encrypt using AES

Regular expressions are a language of their own. When you learn a new programming language, they're this little sub-language that makes no sense at first glance. Many times you have to read another tutorial, article, or book just to understand the "s

SQL 兼容性 更新时间:2017-06-07 13:26:11     DRDS 高度兼容 MySQL 协议和语法,但由于分布式数据库和单机数据库存在较大的架构差异,存在 SQL 使用限制.相关兼容性和 SQL 限制描述如下. DRDS SQL 限制 SQL 大类限制 暂不支持用户自定义数据类型.自定义函数. 暂不支持视图.存储过程.触发器.游标. 暂不支持 BEGIN…END.LOOP…END LOOP.REPEAT…UNTIL…END REPEAT.WHILE…DO…END WHILE 等

https://medium.com/@dan_abramov/smart-and-dumb-components-7ca2f9a7c7d0 There’s a simple pattern I find immensely useful when writing React applications. If you’ve been doing React for a while, you have probably already discovered it. This article exp

一.分词器 1. 认识分词器  1.1 Analyzer   分析器 在ES中一个Analyzer 由下面三种组件组合而成: character filter :字符过滤器,对文本进行字符过滤处理,如处理文本中的html标签字符.处理完后再交给tokenizer进行分词.一个analyzer中可包含0个或多个字符过滤器,多个按配置顺序依次进行处理. tokenizer:分词器,对文本进行分词.一个analyzer必需且只可包含一个tokenizer. token filter:词项过滤器,对to

There are two ways to generate output using Spring MVC: You can use the RESTful @ResponseBody approach and HTTP message converters, typically to return data-formats like JSON or XML. Programmatic clients, mobile apps and AJAX enabled browsers are the

Robot Framework -- A generic test automation framework Version: 3.0 (Python 3.4.0 on win32) Usage: robot [options] data_sources or: python -m robot [options] data_sources or: python path/to/robot [options] data_sources or: java -jar robotframework.ja

ansible命令使用 查看每个服务器的主机名 1 $ ansible multi -a "hostname" 使用一个线程执行命令,相当于顺序在每个服务器上运行(默认5个线程执行) 1 $ ansible multi -a "hostname" -f 1 查看你的环境情况: 查看磁盘使用情况 1 $ ansible multi -a "df -h" 查看内存使用情况 1 $ ansible multi -a "free -m"