自定义配置文件到spring 中，有时候想做一些数据结构的配置化信息，根据业务做一个扩展。
首先：
在项目的META-INF目录下新建两个文件spring.handlers，和spring.shcemas
Spring.handlers在类org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver中已经写死了要取mapping的handlerMappingsLocation的路径
public static finalString DEFAULT_HANDLER_MAPPINGS_LOCATION ="META-INF/spring.handlers";
Spring.Schemas 在org.springframework.beans.factory.xml.PluggableSchemaResolver这个类中
同样写死了位置
public static finalString DEFAULT_SCHEMA_MAPPINGS_LOCATION = "META-INF/spring.schemas";
初始化的时候第一次调用的时候会调用
PropertiesLoaderUtils.loadAllProperties(this.schemaMappingsLocation,this.classLoader)
把所有的文件名包含的取出来放入map中。
spring.handlers内容：
http\:///custom/mytest=com.ruishenh.spring.config.MyNamespaceHandler
spring.schemas内容：
http\:///custom/mytest/myTest.xsd=customTag/myTest.xsd
customTag/myTest.xsd文件：
<?xml version="1.0"encoding="UTF-8"?><xsd:schema xmlns="/custom/myTest"xmlns:xsd="/2001/XMLSchema" targetNamespace="/custom/mytest"elementFormDefault="qualified" attributeFormDefault="unqualified"><xsd:element name="executor"><xsd:complexType><xsd:attribute name="name" type="xsd:string"></xsd:attribute><xsd:attribute name="delay" type="xsd:int"></xsd:attribute><xsd:attribute name="interval" type="xsd:int"use="required"></xsd:attribute><xsd:attribute name="address" type="xsd:string"></xsd:attribute><xsd:attribute name="entity" type="xsd:string"></xsd:attribute></xsd:complexType></xsd:element><xsd:element name="entity"><xsd:complexType><xsd:attribute name="name" type="xsd:string"><xsd:annotation><xsd:documentation><![CDATA[ bean Name ]]></xsd:documentation></xsd:annotation></xsd:attribute><xsd:attribute name="splitBy" type="xsd:string"><xsd:annotation><xsd:documentation xml:lang="zh"><![CDATA[ sqoop分割字段 ]]></xsd:documentation></xsd:annotation></xsd:attribute><xsd:attribute name="sql" type="xsd:string"><xsd:annotation><xsd:documentation xml:lang="zh"><![CDATA[数据库操作sql]]></xsd:documentation></xsd:annotation></xsd:attribute><xsd:attribute name="dbTypeID"><xsd:annotation><xsd:documentation xml:lang="zh"><![CDATA[ 指定数据库类型 如果类型不存在就判断dbTypeName属性,1是mysql，2是oracle，3是sqlserver ]]></xsd:documentation></xsd:annotation><xsd:simpleType><xsd:restriction base="xsd:int"><xsd:enumeration value="1" /><xsd:enumeration value="2" /><xsd:enumeration value="3" /></xsd:restriction></xsd:simpleType></xsd:attribute><xsd:attribute name="dbTypeName"><xsd:annotation><xsd:documentation xml:lang="zh"><![CDATA[ 指定数据库指定名称 如果 dbTypeID 不存在就取当前值 ]]></xsd:documentation></xsd:annotation><xsd:simpleType><xsd:restriction base="xsd:string"><xsd:enumeration value="mysql" /><xsd:enumeration value="oracle" /><xsd:enumeration value="sqlserver" /></xsd:restriction></xsd:simpleType></xsd:attribute></xsd:complexType></xsd:element></xsd:schema>
spring/myTest.xml文件：
<?xml version="1.0"encoding="UTF-8"?><beans xmlns="/schema/beans"xmlns:xsi="/2001/XMLSchema-instance"xmlns:mi="/custom/mytest"xsi:schemaLocation="/schema/beans/schema/beans/spring-beans.xsd/custom/mytest/custom/mytest/myTest.xsd"><mi:entity dbTypeID="1" dbTypeName="mysql"splitBy="id" sql="1"name="mye" /><mi:executor interval="5000" address="127.0.0.1"delay="2000"name="myexecutor" entity="mye" /></beans>
com.ruishenh.spring.config.MyNamespaceHandler 命名空间处理类：
package com.ruishenh.spring.config;import org.springframework.beans.factory.xml.NamespaceHandlerSupport;public class MyNamespaceHandler extends NamespaceHandlerSupport{@Overridepublic void init() {registerBeanDefinitionParser("executor",newMyBeanDefinitionParser(MyExecutor.class));registerBeanDefinitionParser("entity",newMyBeanDefinitionParser(MyEntity.class));}}
这个类主要是在DefaultNamespaceHandlerResolver这个类中getHandlerMappings（）取到了所有的META-INF/spring.handlers的文件内容存入map，然后根据当前的命名空间找到对应的NamespaceHandler，然后反射出对象调用init（）
Class<?> handlerClass =ClassUtils.forName(className, this.classLoader);if (!NamespaceHandler.class.isAssignableFrom(handlerClass)){throw new FatalBeanException("Class ["+ className + "] for namespace [" + namespaceUri +"] does not implement the [" + NamespaceHandler.class.getName() + "] interface");}NamespaceHandlernamespaceHandler = (NamespaceHandler) BeanUtils.instantiateClass(handlerClass);namespaceHandler.init();
com.ruishenh.spring.config.MyBeanDefinitionParser解析类：
packagecom.ruishenh.spring.config;importorg.springframework.beans.factory.config.BeanDefinition;importorg.springframework.beans.factory.config.RuntimeBeanReference;importorg.springframework.beans.factory.support.RootBeanDefinition;importorg.springframework.beans.factory.xml.BeanDefinitionParser;importorg.springframework.beans.factory.xml.ParserContext;importorg.w3c.dom.Element;importorg.w3c.dom.NamedNodeMap;importorg.w3c.dom.Node;public classMyBeanDefinitionParser implements BeanDefinitionParser {private Class<?> clssze;publicMyBeanDefinitionParser(Class<?> cls) {this.clssze = cls;}@Overridepublic BeanDefinition parse(Elementelement, ParserContext parserContext) {RootBeanDefinitionbeanDefinition = new RootBeanDefinition();beanDefinition.setBeanClass(clssze);String id = null;id =element.getAttribute("name");if (id == null) {if (clssze ==MyExecutor.class) {id = "test_myExecutor";} else if (clssze ==MyEntity.class) {id ="test_myentity";} else {throw newIllegalStateException("MyBeanDefinitionParser.parse,未知的业务逻辑处理：class:" +element.getAttribute("class"));}}int counter = 2;while(parserContext.getRegistry().containsBeanDefinition(id)) {id = id +(counter++);}if (id != null &&id.length() > 0) {if(parserContext.getRegistry().containsBeanDefinition(id)) {throw newIllegalStateException("Duplicate spring bean id " + id);}parserContext.getRegistry().registerBeanDefinition(id,beanDefinition);}NamedNodeMap nnm =element.getAttributes();for (int i = 0; i <nnm.getLength(); i++) {Node node =nnm.item(i);String key =node.getLocalName();String value =node.getNodeValue();if(key.equals("entity")) {if(parserContext.getRegistry().containsBeanDefinition(value)) {beanDefinition.getPropertyValues().add(key,parserContext.getRegistry().getBeanDefinition(value));} else {beanDefinition.getPropertyValues().add(key,new RuntimeBeanReference(value));}} else {beanDefinition.getPropertyValues().add(key,value);}}return beanDefinition;}}
这个类会在
org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(Elementroot, BeanDefinitionParserDelegate delegate)这个方法中入口执行
然后到org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(Elementelement, ParserContext parserContext);
最后找到对应的BeanDefinitionParser执行parse方法。至于放入BeanDefinitionParser的入口就在自定义的NamespaceHandler中init（）方法中。
com/ruishenh/spring/config/MyEntity.java实体类：
package com.ruishenh.spring.config;import com.ruishenh.model.BaseModel;public classMyEntity extendsBaseModel{private int dbTypeID;private String dbTypeName;private String splitBy;private String sql;private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getSplitBy() {return splitBy;}public void setSplitBy(StringsplitBy) {this.splitBy = splitBy;}public String getSql() {return sql;}public void setSql(String sql) {this.sql = sql;}public int getDbTypeID() {return dbTypeID;}public void setDbTypeID(int dbTypeID) {this.dbTypeID = dbTypeID;}public String getDbTypeName(){return dbTypeName;}public void setDbTypeName(StringdbTypeName) {this.dbTypeName = dbTypeName;}}
com/ruishenh/spring/config/MyExecutor.java实体类：
package com.ruishenh.spring.config;import com.ruishenh.model.BaseModel;public classMyExecutor extends BaseModel{private String name;private int delay;private int interval;private String address;private MyEntity entity;public MyEntity getEntity() {return entity;}public void setEntity(MyEntity entity) {this.entity = entity;}public int getDelay() {return delay;}public void setDelay(int delay) {this.delay = delay;}public int getInterval() {return interval;}public void setInterval(int interval) {this.interval = interval;}public String getAddress() {return address;}public void setAddress(Stringaddress) {this.address = address;}public String getName() {return name;}public void setName(String name) {this.name = name;}}
测试类：
package com.ruishenh.spring.test;import org.springframework.context.support.FileSystemXmlApplicationContext;import com.ruishenh.spring.config.MyEntity;import com.ruishenh.spring.config.MyExecutor;public classTest {public static void main(String[] args) {Stringconf = "classpath:spring/myTest.xml";FileSystemXmlApplicationContextac = newFileSystemXmlApplicationContext(conf);MyExecutorme = ac.getBean(MyExecutor.class);System.out.println(me.toString());MyEntity mye = ac.getBean(MyEntity.class);System.out.println(mye.toString());}}
运行结果:
MyExecutor[name=myexecutor,delay=2000,interval=5000,address=127.0.0.1,entity=MyEntity[dbTypeID=1,dbTypeName=mysql,splitBy=id,sql=1,name=mye]]
MyEntity[dbTypeID=1,dbTypeName=mysql,splitBy=id,sql=1,name=mye]
