基于spring的schema自定义扩展(二)

上文分析了spring如何解析xml中标签

自定义schema规范约束

1. 新建test-schema.xsd文件定义如下内容

<xsd:schema xmlns="http://www.myhost.com/schema/demo" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:beans="http://www.springframework.org/schema/beans"
            targetNamespace="http://www.myhost.com/schema/demo"
            elementFormDefault="qualified" attributeFormDefault="unqualified">
    <xsd:import namespace="http://www.springframework.org/schema/beans"/>
    <xsd:element name="demo" type="Tdemo" />
    <xsd:complexType name="Tdemo">
        <xsd:attribute name="id" type="xsd:string"/>
        <xsd:attribute name="interFace" type="xsd:string"/>
        <xsd:attribute name="version" type="xsd:string"/>
    </xsd:complexType>
</xsd:schema>

2. 将文件放在META-INF目录下
3. 在META-INF目录下新建spring.schemas文件，内容如下：

http\://www.myhost.com/schema/demo/test-schema.xsd=META-INF/test-schema.xsd

自定义shema实现

• 继承NamespaceHandlerSupport类

public class SpringParseNameSpaceHandler extends NamespaceHandlerSupport {
    @Override
    public void init() {
        registerBeanDefinitionParser("demo" ,new DemoDefiniParse());
    }
}

在META-INF目录下新建spring.handlers文件，内容如下：

http\://www.myhost.com/schema/demo=com.test.SpringParseNameSpaceHandler

• 实现BeanDefinitionParser接口

//AbstractSingleBeanDefinitionParser继承于AbstractBeanDefinitionParser，而AbstractBeanDefinitionParser已实现BeanDefinitionParser接口
public class DemoDefiniParse extends AbstractSingleBeanDefinitionParser {

    @Override
    protected void doParse(Element element, BeanDefinitionBuilder builder) {
        String id = element.getAttribute("id");
        String interFace = element.getAttribute("interFace");
        String version = element.getAttribute("version");
        builder.addPropertyValue("id",id);
        builder.addPropertyValue("interFace",interFace);
        builder.addPropertyValue("version",version);
    }

    @Override
    protected Class<?> getBeanClass(Element element) {
        return Demo.class;
    }
}

• 定义bean类Demo

public class Demo {

    private String id;

    private String interFace;

    private String version;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getInterFace() {
        return interFace;
    }

    public void setInterFace(String interFace) {
        this.interFace = interFace;
    }

    public String getVersion() {
        return version;
    }

    public void setVersion(String version) {
        this.version = version;
    }
}

• 新建xml配置文件spring-demo.xml

 xmlns:pta="http://www.myhost.com/schema/demo"  :
 xmlns：固定开头
 pta:自定义前缀，一般都有含义，如dubbo框架xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" 注册服务<dubbo:service>，dubbo由此处定义
 http://www.myhost.com/schema/demo ： 取值于test-schema.xsd中的targetNamespace

xsi:schemaLocation="http://www.springframework.org/schema/beans
	     http://www.springframework.org/schema/beans/spring-beans.xsd
		 http://www.myhost.com/schema/demo http://www.myhost.com/schema/demo/test-schema.xsd"
http://www.myhost.com/schema/demo：如上
http://www.myhost.com/schema/demo/test-schema.xsd：约束

<?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:pta="http://www.myhost.com/schema/demo"
	   xsi:schemaLocation="http://www.springframework.org/schema/beans
	     http://www.springframework.org/schema/beans/spring-beans.xsd
		 http://www.myhost.com/schema/demo http://www.myhost.com/schema/demo/test-schema.xsd"
	   default-autowire="byName">


	<pta:demo id="test" interFace="org.springframework.jdbc.core.JdbcTemplate" version="1.0"></pta:demo>
     
</beans>

• 本地测试

public class SpringParseDemo {

    public static void main(String[] args) {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:spring-demo.xml");
        applicationContext.getApplicationName();
        Object sit = applicationContext.getBean("test");
        System.out.println(sit);
    }
}