spring自定义标签

假如我们有一个User类，现在需要通过自定义标签，把这个对象初始化到springApplicationContext中以便于注入使用。

• 新建User类

public class User {

    private String id;  
    private String userName;  
    private String email;  
    public String getId() {  
        return id;  
    }  
    public void setId(String id) {  
        this.id = id;  
    }  
    public String getUserName() {  
        return userName;  
    }  
    public void setUserName(String userName) {  
        this.userName = userName;  
    }  
    public String getEmail() {  
        return email;  
    }  
    public void setEmail(String email) {  
        this.email = email;  
    }  

}

• 增加xml定义文件 spring-user.xsd

<?xml version="1.0" encoding="UTF-8"?>  
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"  
    xmlns="http://www.wjs.com/schema/user" targetNamespace="http://www.wjs.com/schema/user"  
    elementFormDefault="qualified">  
    <xsd:element name="user">  
        <xsd:complexType>  
            <xsd:attribute name="id" type="xsd:string" />  
            <xsd:attribute name="userName" type="xsd:string" />  
            <xsd:attribute name="email" type="xsd:string" />  
        </xsd:complexType>  
    </xsd:element>  

</xsd:schema>

• 定义beanDefiniton类 获取xml中对应定义的属性

import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
import org.springframework.util.StringUtils;
import org.test.spirng.xml.bean.definition.User;
import org.w3c.dom.Element;

public class UserBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
    @Override
    protected Class<?> getBeanClass(Element element) {
        return User.class;
    }

    @Override
    protected void doParse(Element element, BeanDefinitionBuilder builder) {
        String userName = element.getAttribute("userName");
        String email = element.getAttribute("email");
        if (StringUtils.hasText(userName)) {
            builder.addPropertyValue("userName", userName);
        }
        if (StringUtils.hasText(email)) {
            builder.addPropertyValue("email", email);
        }
    }

}

• 定义namespaceHandler 处理xml 中对应的标签

import org.springframework.beans.factory.xml.NamespaceHandlerSupport;  
public class MyUserNamespaceHandler extends NamespaceHandlerSupport {  
  
    @Override  
    public void init() {  
        registerBeanDefinitionParser("user",new UserBeanDefinitionParser());  
    }  

}

• 配置标签对应的处理类spring.handlers

http://www.wjs.com/schema/user=org.test.spirng.xml.bean.definition.definition.MyUserNamespaceHandler

• 配置标签描述文件 即xsd文件

http://www.wjs.com/schema/user.xsd=META-INF/spring-user.xsd

• 用法

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns="http://www.springframework.org/schema/beans"
       xmlns:myTag="http://www.wjs.com/schema/user"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://www.wjs.com/schema/user http://www.wjs.com/schema/user.xsd">


    <myTag:user id="testBean" userName="name" email="wjs@163.com"/>
    <myTag:user id="testBean1" userName="name1" email="wjs@163.com"/>
</beans>

整个工程的截图

工程代码见附件。（去掉pom里的parnet标签即可使用）

https://files.cnblogs.com/files/z-test/test-spirng-xml-bean-definition.rar