基于Spring可扩展Schema提供自定义配置支持

spring 可以基于schema 扩展，自定义 schema。参考文档自己搭了个应用试验了一下：



首先看下自己写的 myns.xsd

Xml代码


<?xml version="1.0" encoding="UTF-8"?>

<xsd:schema xmlns="http://www.yjhexy.com/schema/myns"

xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:beans="http://www.springframework.org/schema/beans"

targetNamespace="http://www.yjhexy.com/schema/myns" elementFormDefault="qualified"

attributeFormDefault="unqualified">

<xsd:import namespace="http://www.springframework.org/schema/beans" />

<xsd:element name="dateformat">

<xsd:complexType>

<xsd:complexContent>

<xsd:extension base="beans:identifiedType">

<xsd:attribute name="lenient" type="xsd:boolean" />

<xsd:attribute name="pattern" type="xsd:string" use="required" />

</xsd:extension>

</xsd:complexContent>

</xsd:complexType>

</xsd:element>

</xsd:schema>

然后看下我的applicationContxt.xml配置:

Xml代码


<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:myns="http://www.yjhexy.com/schema/myns"

xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.yjhexy.com/schema/myns http://www.yjhexy.com/schema/myns/myns.xsd

">

<myns:dateformat id="dateFormat" pattern="yyyy-MM-dd HH:mm"

lenient="true" />

</beans>

很明显实现了个自定义的bean ,这个bean有两个属性，一个是时间的格式，另外一个不知道啥东西。

然后在META-INF下面写了两个文件，

spring.handlers:用来描述如何处理自定义的namespace

Xml代码


http\://www.yjhexy.com/schema/myns=com.yajun.balance.spring.MyNamespaceHandler

spring.schemas:描述schema的位置

Xml代码


http\://www.yjhexy.com/schema/myns/myns.xsd=com/yajun/balance/spring/myns.xsd

然后是需要两个类，一个处理namespace,一个处理beanDefinition

Java代码


package com.yajun.balance.spring;

import org.springframework.beans.factory.xml.NamespaceHandlerSupport;

public class MyNamespaceHandler extends NamespaceHandlerSupport {

public void init() {

registerBeanDefinitionParser("dateformat", new SimpleDateFormatBeanDefinitionParser());

}

}

Java代码


package com.yajun.balance.spring;

import java.text.SimpleDateFormat;

import org.springframework.beans.factory.support.BeanDefinitionBuilder;

import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;

import org.springframework.util.StringUtils;

import org.w3c.dom.Element;

public class SimpleDateFormatBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {

protected Class getBeanClass(Element element) {

return SimpleDateFormat.class;

}

protected void doParse(Element element, BeanDefinitionBuilder bean) {

// this will never be null since the schema explicitly requires that a value be supplied

String pattern = element.getAttribute("pattern");

bean.addConstructorArgValue(pattern);

// this however is an optional property

String lenient = element.getAttribute("lenient");

if (StringUtils.hasText(lenient)) {

bean.addPropertyValue("lenient", Boolean.valueOf(lenient));

}

}

}

最后main输出试试：

Java代码


package com.yajun.balance.spring;

import java.text.SimpleDateFormat;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainTest {

public static void main(String[] args) {

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

SimpleDateFormat f = (SimpleDateFormat) ctx.getBean("dateFormat");

System.out.println(f);

}

}