摘自：https://blog.csdn.net/ll840768874/article/details/77369204
最近看spring源码，看到了Spring提供了可扩展的schema的支持。
1.设计配置属性javabean
2.编写xsd文件
3.编写NamespaceHandlerSupport和BeanDefinitionParser
4.在spring.schemas和spring.handlers中填入关系，使之能关联起来
1.编写JavaBean：
public class Userconfig implements Serializable {
private static final long serialVersionUID = -5680714598279222721L;
private String id;
private String name;
private String password;
private String phone;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("name="+name).append(" password="+password).append(" phone="+phone);
return sb.toString();
}
2.编写xsd文件放在META-INF文件下。PS：maven项目如果没有META-INF文件，需要自己在resources文件夹下创建META-INF文件
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<xsd:schema xmlns="http://code.loup.com/schema/loup"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://code.loup.com/schema/loup"
elementFormDefault="qualified">
<xsd:import namespace="http://www.w3.org/XML/1998/namespace"></xsd:import>
<xsd:element name="user">
<xsd:complexType>
<xsd:attribute name="id" type="xsd:string"></xsd:attribute>
<xsd:attribute name="name" type="xsd:string"></xsd:attribute>
<xsd:attribute name="password" type="xsd:string"></xsd:attribute>
<xsd:attribute name="phone" type="xsd:string"></xsd:attribute>
</xsd:complexType>
</xsd:element>
</xsd:schema>
3. 编写NamespaceHandlerSupport，写一个类继承NamespaceHandlerSupport
public class UserHandlers extends NamespaceHandlerSupport {
@Override
public void init() {
registerBeanDefinitionParser("user", new UserParserDefinitons());
}
}
然后编写BeanDefinitionParser，写一个解析类，继承AbstractBeanDefinitionParser，重写getBeanClass方法和doParse方法，getBeanClass返回的是之前编写的Javabean
public class UserParserDefinitons extends AbstractSingleBeanDefinitionParser {
@Override
protected Class<?> getBeanClass(Element element) {
return Userconfig.class;
}
@Override
protected void doParse(Element element, BeanDefinitionBuilder builder) {
String name = element.getAttribute("name");
String password = element.getAttribute("password");
String phone = element.getAttribute("phone");
builder.addPropertyValue("name",name);
builder.addPropertyValue("password",password);
builder.addPropertyValue("phone",phone);
}
}
4.新建spring.schemas,注意此文件放在META-INF文件下，spring加载的时候会读取，里面填入
http\://code.loup.com/schema/loup/loup.xsd=META-INF/loup.xsd
然后新建spring.handlsers，此文件也是放在META-INF文件下，里面填写之前编写的xsd的Namespace的路劲和第三步编写的handlers对应关系
http\://code.loup.com/schema/loup=com.seckill.handlers.UserHandlers
至此简单的自定义扩展已经结束
在spring的文件中引用
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:loup="http://code.loup.com/schema/loup"
xsi:schemaLocation="http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://code.loup.com/schema/loup
http://code.loup.com/schema/loup/loup.xsd">
<loup:user id="testLoup" name="loup" password="123456" phone="111111"></loup:user>
</beans>
写个测试方法
public void test(){
ApplicationContext context = new ClassPathXmlApplicationContext("conf/spring-test.xml");
Userconfig userconfig = (Userconfig) context.getBean("testLoup");
System.out.println(userconfig);
}
输出的内容：