Spring 2.0 XML schema-based configuration

摘自：http://static.springsource.org/spring/docs/2.5.x/reference/xsd-config.html

 

原文是spring framework reference的附录A，介绍XML基于模式的配置

 

The central motivation for moving to XML Schema based configuration files was to make Spring XML configuration easier. The 'classic' <bean/> -based approach is good, but its generic-nature comes with a price in terms of configuration overhead.

From the Spring IoC containers point-of-view, everything is a bean. That's great news for the Spring IoC container, because if everything is a bean then everything can be treated in the exact same fashion. The same, however, is not true from a developer's point-of-view. The objects defined in a Spring XML configuration file are not all generic, vanilla beans. Usually, each bean requires some degree of specific configuration.

Spring 2.0's new XML Schema-based configuration addresses this issue. The <bean/> element is still present, and if you wanted to, you could continue to write the exact same style of Spring XML configuration using only <bean/> elements. The new XML Schema-based configuration does, however, make Spring XML configuration files substantially clearer to read. In addition, it allows you to express the intent of a bean definition.

The key thing to remember is that the new custom tags work best for infrastructure or integration beans: for example, AOP, collections, transactions, integration with 3rd-party frameworks such as Mule, etc., while the existing bean tags are best suited to application-specific beans, such as DAOs, service layer objects, validators, etc.

 

一些常用的基于模式的命名空间标签：

 

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"                   -----------------参见http://blog.springsource.com/2006/11/25/xml-syntax-sugar-in-spring-20/
    xmlns:context="http://www.springframework.org/schema/context"  -----------------context schema中的property-placeholder，用于设置 PropertyPlaceholderConfigurer
    xmlns:aop="http://www.springframework.org/schema/aop"            -----------------AOP
    xmlns:tx="http://www.springframework.org/schema/tx"                   -----------------事务管理

    xmlns:util="http://www.springframework.org/schema/util"               ------------------工具类
    xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

<!-- <bean/> definitions here -->





</bean>