dubbo源码学习(二) : spring 自定义标签

标签：java   dubbo   spring   自定义标签   

1、编写实体类
2、编写Parser解析类
3、编写NameSpaceHandle类
4、配置spring.handlers
5、配置spring.schemas
6、配置customTag .xsd

标签实体类如下：

public class CustomTag {

private String id;

private String name;

private Integer age;

private String profession;

private String address;

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 Integer getAge() {
    return age;
}

public void setAge(Integer age) {
    this.age = age;
}

public String getProfession() {
    return profession;
}

public void setProfession(String profession) {
    this.profession = profession;
}

public String getAddress() {
    return address;
}

public void setAddress(String address) {
    this.address = address;
}

public String getPhone() {
    return phone;
}

public void setPhone(String phone) {
    this.phone = phone;
}

public String toString(){
    StringBuffer sb = new StringBuffer();
    sb.append(id + "\n");
    sb.append(name + "\n");
    sb.append(age + "\n");
    sb.append(profession + "\n");
    sb.append(address + "\n");
    sb.append(phone + "\n");
    return sb.toString();
}

}

标签的解析类如下:

    public class CustomTagBeanDefinitionParser extends AbstractSingleBeanDefinitionParser {
        private final Class<?> beanClass;

        private final boolean required;

        public CustomTagBeanDefinitionParser (Class<?> beanClass, boolean required) {
                this.beanClass = beanClass;
                this.required = required;
        }

        protected Class getBeanClass(Element element) {
                return CustomTag.class;
        }

        protected void doParse(Element element, BeanDefinitionBuilder builder) {
                //通过配置文件获取相应的值，设置到bean的属性中
                String id = element.getAttribute("id");
                String name = element.getAttribute("name");
                String age = element.getAttribute("age");
                String profession = element.getAttribute("profession");
                String address = element.getAttribute("address");
                String phone = element.getAttribute("phone");
                if (StringUtils.hasText(id)) {
                        builder.addPropertyValue("id", id);
                }
                if (StringUtils.hasText(name)) {
                        builder.addPropertyValue("name", name);
                }
                if (StringUtils.hasText(age)) {
                        builder.addPropertyValue("age", age);
                }
                if (StringUtils.hasText(profession)) {
                        builder.addPropertyValue("profession", profession);
                }
                if (StringUtils.hasText(address)) {
                        builder.addPropertyValue("address", address);
                }
                if (StringUtils.hasText(phone)) {
                        builder.addPropertyValue("phone", phone);
                }
        }

}

NameSpaceHandle类如下：

public class CustomTagNamespaceHandler extends NamespaceHandlerSupport {
        @Override
        public void init() {
                //实现init方法,解析CustomTag标签
                registerBeanDefinitionParser("customTag",new CustomTagBeanDefinitionParser(CustomTag.class,true));
        }
}

spring.handlers配置，前面那一串其实可以随便配置，只要一会和后面的配置一致即可

http\://www.51gitee.net/schema/customTag=springNameSpace.CustomTagNamespaceHandler

spring.schemas配置

http\://www.51gitee.net/schema/customTag/customTag.xsd=META-INF/customTag.xsd

customTag.xsd的配置

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema
                xmlns="http://www.51gitee.net/schema/customTag"
                xmlns:xsd="http://www.w3.org/2001/XMLSchema"
                xmlns:beans="http://www.springframework.org/schema/beans"
                targetNamespace="http://www.51gitee.net/schema/customTag"
                elementFormDefault="qualified"
                attributeFormDefault="unqualified">
        <xsd:import namespace="http://www.springframework.org/schema/beans" />
        <!-- 定义element名, customTagType对应了bean的属性  -->
        <xsd:element name="customTag" type="customTagType">
                <xsd:annotation>
                        <xsd:documentation><![CDATA[ The customTag config ]]></xsd:documentation>
                </xsd:annotation>
        </xsd:element>
        <!--  配置各属性值，有点像Mybatis配置对应的model   -->
        <xsd:complexType name="customTagType">
                <xsd:attribute name="id" type="xsd:ID">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The unique identifier for a bean. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
                <xsd:attribute name="name" type="xsd:string" use="required">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The customTag name. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
                <xsd:attribute name="age" type="xsd:int">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The customTag age. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
                <xsd:attribute name="profession" type="xsd:string">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The customTag profession. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
                <xsd:attribute name="address" type="xsd:string">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The customTag address. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
                <xsd:attribute name="phone" type="xsd:string">
                        <xsd:annotation>
                                <xsd:documentation><![CDATA[ The customTag phone. ]]></xsd:documentation>
                        </xsd:annotation>
                </xsd:attribute>
        </xsd:complexType>

</xsd:schema>

最后测试
在新建一个spring的配置文件如下

<?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:common="http://www.51gitee.net/schema/customTag"
             xsi:schemaLocation="
         http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
         http://www.oschina.net/schema/customTag
         http://www.oschina.net/schema/customTag/customTag.xsd">

        <common:customTag id="test"  name="chewenliang" address="bei jing" age="12" phone="18618152379" profession="技术" />

</beans>

在java代码中测试

public class TestNameSpace {
        public static void main(String[] args) {
                ApplicationContext context = new ClassPathXmlApplicationContext("spring-test.xml");
                CustomTag customTag= (CustomTag) context.getBean("test");
                System.out.println(customTag.toString());
        }
}

输出结果：

  test  
chewenliang  
12  
技术  
bei jing  
18618152379  

spring的自定义标签自己很容易实现，具体要看在实际项目中如何正确的实用它，接下来会记录dubbo是如何解析、暴露服务。

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dubbo源码学习(二) : spring 自定义标签

标签：java   dubbo   spring   自定义标签   

原文地址：http://blog.51cto.com/13538361/2096231