What is Spring Roo？

转自 http://wangzaixiang.blogspot.com/2009/06/what-is-spring-roo.html

Spring出来了一个叫做Roo的东东，一直没有时间去看看，引文Spring出品的东西一向来说，都是珍品诸多的，但从spring的官网上，居然没办法了解Roo到底是个什么玩意（投资放大了，但文档却做得越来越差了）。好在Roo实在是一个小玩意，下载还不到3M，于是马上下载下来，一读为快。

• 下载
• 解压
• 运行 roo.bat 进入到roo shell，就可以一步一步的按照提示进行了。（这个做得不错，居然没有文档，也可以按照提示进行操作）

这里吧 roo 支持的命令一一列出来，各位看官可以对 roo 的功能有一个初步的了解：

* */ - End of block comment

* /* - Start of block comment

* // - Inline comment markers

* ; - Inline comment markers

* add dependency - Adds a new dependency to the Maven project object model (POM)

* add field boolean - Adds a private boolean field to an existing Java source file

* add field date jdk - Adds a private date field to an existing Java source file

* add field date jpa - Adds a private JPA-specific date field to an existing Java source file

* add field email template - insert a MailTemplate field into an existing type

* add field number - Adds a private numeric field to an existing Java source file

* add field reference jpa - Adds a private reference field to an existing Java source file (ie the 'many' side of a many-to-one)

* add field set jpa - Adds a private Set field to an existing Java source file (ie the 'one' side of a many-to-one)

* add field string - Adds a private string field to an existing Java source file

* configure email template - configure a template for a SimpleMailMessage

* configure logging - Configure logging in your project

* database properties - Shows database configuration details

* database remove - Removes a particular database property

* database set - Changes a particular database property

* date - Displays the local date and time

* development mode - Switches the system into development mode (greater diagnostic information)

* exit - Exits the shell

* generate class file - Creates a new Java source file in any project path

* help - Shows system help

* hint - Provides step-by-step hints and context-sensitive guidance

* insert field - Inserts a private field into the specified file

* install email provider - Install a Email provider in your project

* install finder - Install finders in the given target (must be an entity)

* install jms - Install a JMS provider in your project

* install security - Install Spring Security into your project

* install web flow - Install Spring Web Flow configuration artifacts into your project

* list finders for - List all finders for a given target (must be an entity

* metadata for id - Shows detailed information about the metadata item

* metadata for type - Shows detailed metadata for the indicated type

* metadata summary - Shows statistics on the metadata system

* metadata trace - Traces metadata event delivery notifications (0=none, 1=some, 2=all)

* new controller automatic - Create a new automatic Controller (ie where we maintain CRUD automatically)

* new controller manual - Create a new manual Controller (ie where you write the methods)

* new dod - Creates a new data on demand for the specified entity

* new integration test - Creates a new data on demand for the specified entity

* new java file - Creates a new Java source file in SRC_MAIN_JAVA

* new mock test - Creates a mock test for the specified entity

* new persistent class jpa - Creates a new JPA persistent entity in SRC_MAIN_JAVA

* new selenium test - Creates a new Selenium test for a particular controller

* new test file - Creates a new Java source file in SRC_TEST_JAVA

* property file details - Shows the details of a particular properties file

* property file remove - Removes a particular properties file property

* property file set - Changes a particular properties file property

* props - Shows the shell's properties

* quit - Exits the shell

* remove dependency - Removes an existing dependency from the Maven project object model (POM)

* script - Parses the specified resource file and executes its commands

* update jpa - Update the JPA persistence provider in your project

* version - Displays shell version

** Type 'hint' (without the quotes) and hit ENTER for step-by-step guidance **

我还没有对Roo进行深入的研究，初步的感觉是：

1、Roo的 TAB  做的真是很好，TAB在Bash中有一定的帮助作用，但仅限于有限的文件名自动完成，而Roo的命令行自动完成有点接近于IDE中的代码自动完成了。

2、Hint 做得也真好，居然，在没有文档和帮助的情况下，我可以（近乎）熟练的操作一个命令行工具。要记得，当初我学习Unix还是花了些功夫的。

3、最后的感觉是：Roo好像就是一个基于命令行的IDE，其功能无非就是一个IDE中会有的项目向导功能，包括命令行自动完成，也是IDE中的一些概念而已，本质上倒没有什么突破。而且，从实际投入而言，对于最终用户来说，一个命令行的Roo无论如何从使用便利性而言，是不如像eclipse之类的IDE的。不过，开发IDE所需时间、复杂度要大得多，Roo这种模式倒不失为一种IDE的快速开发原型吧。

4、Roo的本质是一个代码自动生成的工具，代码自动生产到底能够多大程度的应用到企业开发中，对项目开发效率能有多大提高，我觉得有些怀疑。作为教学用途，或者快速原型，倒是不错的选择。