spring schema自定义扩展

spring schema自定义扩展

Spring 2.5在2.0的基于Schema的Bean配置的基础之上，再增加了扩展XML配置的机制。通过该机制，我们可以编写自己的Schema，并根据自定义的Schema用自定的标签配置Bean。要使用的Spring的扩展XML配置机制，也比较简单，有以下4个步骤：

编写自定义Schema文件；编写自定义NamespaceHandler；编写解析BeanDefinition的parser在Spring中注册上述组建

Maven依赖

<dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.2.4.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>3.2.4.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>3.2.4.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>3.2.4.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>3.2.4.RELEASE</version> </dependency>

一、编写schema文件

参考：http://www.w3school.com.cn/schema/schema_elements_ref.asp , 如下people.xsd文件:

<?xml version="1.0" encoding="UTF-8"?> <xsd:schema xmlns="http://www.pomelo.com/schema/people" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:beans="http://www.springframework.org/schema/beans" targetNamespace="http://www.pomelo.com/schema/people" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xsd:import namespace="http://www.springframework.org/schema/beans"/> <xsd:element name="student"> <xsd:complexType> <xsd:complexContent> <xsd:extension base="beans:identifiedType"> <xsd:attribute name="name" type="xsd:string"> <xsd:annotation> <xsd:documentation>姓名</xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="age" type="xsd:string"> <xsd:annotation> <xsd:documentation>年龄</xsd:documentation> </xsd:annotation> </xsd:attribute> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:element> </xsd:schema>

二、编写自定义NamespaceHandler

package schema; import org.springframework.beans.factory.xml.NamespaceHandlerSupport; public class StudentNamespaceHandler extends NamespaceHandlerSupport { @Override public void init() { registerBeanDefinitionParser("student", new StudentBeanDefinitionParser()); } }

三、编写BeanDefinition

package schema; import org.springframework.beans.factory.support.BeanDefinitionBuilder; import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser; import org.springframework.util.StringUtils; import org.w3c.dom.Element; public class StudentBeanDefinitionParser extends AbstractSingleBeanDefinitionParser { protected Class getBeanClass(Element element) { return Student.class; } protected void doParse(Element element, BeanDefinitionBuilder bean) { String name = element.getAttribute("name"); bean.addPropertyValue("name", name); String age = element.getAttribute("age"); if (StringUtils.hasText(age)) { bean.addPropertyValue("age", Integer.valueOf(age)); } } }

实体类：

package schema; public class Student { private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }

四、注册schema组件

最后在META-INF目录下添加两个配置文件(spring.handler和spring.schema):

spring.handler配置如下：

http\://www.pomelo.com/schema/people=schema.StudentNamespaceHandler

spring.schema配置如下：

http\://www.pomelo.com/schema/people.xsd=META-INF/people.xsd

五、测试

新建applicationContext.xml放在clasapath下面：

<?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:people="http://www.pomelo.com/schema/people" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.pomelo.com/schema/people http://www.pomelo.com/schema/people.xsd"> <people:student id="student1" name="student1" age="18"/> <people:student id="student2" name="student2" age="20" /> <bean id="student3" class="schema.Student"> <property name="name" value="student3"/> <property name="age" value="23"/> </bean> </beans>

java调用：

package schema; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * Created by zhengyong on 17/3/3. */ public class SchemaTest { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("/applicationContext.xml"); Student student1 = (Student) ctx.getBean("student1"); Student student2 = (Student) ctx.getBean("student2"); Student student3 = (Student) ctx.getBean("student3"); System.out.println("name: " + student1.getName() + " age :" + student1.getAge()); System.out.println("name: " + student2.getName() + " age :" + student2.getAge()); System.out.println("name: " + student3.getName() + " age :" + student3.getAge()); } }

具体代码详见：https://github.com/zyongjava/pomelo/blob/master/src/main/resources/META-INF/people.xsd