Spring REST XML和JSON示例

欢迎来到Spring Restful Web Services XML和JSON示例。前段时间我写了一篇关于Spring REST JSON的文章，收到了很多评论，询问如何更改程序以支持XML。我也收到了一些邮件，询问如何使应用程序同时支持XML和JSON。

Spring REST XML和JSON

I thought to write an article about Spring REST XML and JSON application where I will show you how easily we can extend the existing application to support XML. Since I will be making changes to the existing project, make sure you first download it from below link.

下载Spring Restful Webservice项目

现在按照以下步骤更改Spring bean配置文件。

1. 定义一个类型为Jaxb2RootElementHttpMessageConverter的bean。

   <beans:bean id="xmlMessageConverter" class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter">
   </beans:bean>
   

2. 将上述配置的bean添加到RequestMappingHandlerAdapter属性messageConverters中。

   <beans:bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
   <beans:property name="messageConverters">
   	<beans:list>
   		<beans:ref bean="jsonMessageConverter"/>
   		<beans:ref bean="xmlMessageConverter"/>
   	</beans:list>
   </beans:property>
   </beans:bean>
   

在以上更改之后，我们最终的 Spring bean 配置文件将如下所示：servlet-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="https://www.springframework.org/schema/mvc"
	xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
	xmlns:beans="https://www.springframework.org/schema/beans"
	xmlns:context="https://www.springframework.org/schema/context"
	xsi:schemaLocation="https://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd
		https://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
		https://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

	<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
	
	<!-- Enables the Spring MVC @Controller programming model -->
	<annotation-driven />

	<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
	<resources mapping="/resources/**" location="/resources/" />

	<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
	<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<beans:property name="prefix" value="/WEB-INF/views/" />
		<beans:property name="suffix" value=".jsp" />
	</beans:bean>
	
	<!-- Configure to plugin JSON as request and response in method handler -->
	<beans:bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
		<beans:property name="messageConverters">
			<beans:list>
				<beans:ref bean="jsonMessageConverter"/>
				<beans:ref bean="xmlMessageConverter"/>
			</beans:list>
		</beans:property>
	</beans:bean>
	
	<!-- Configure bean to convert JSON to POJO and vice versa -->
	<beans:bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
	</beans:bean>	
	
	<beans:bean id="xmlMessageConverter" class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter">
	</beans:bean>
	
	<context:component-scan base-package="com.journaldev.spring.controller" />
	
</beans:beans>

我们知道，要使用 JAXB 进行类的编组，我们需要使用 @XmlRootElement 注解对其进行注解。因此，将其添加到我们的 Employee 模型类中。Employee.java

@XmlRootElement
public class Employee implements Serializable{

//代码无变化
}

搞定了，我们完成了。我们的Spring应用将支持JSON和XML。它甚至支持XML请求与JSON响应，反之亦然。以下是一些截图展示了它的工作方式。注意：我在使用Postman Chrome应用程序进行测试，你可以使用任何REST客户端进行测试。1. XML响应: 确保将Accept头设置为“application/xml”。 2. JSON响应: 确保将Accept头设置为“application/json”。 3. XML请求与JSON响应: 确保Accept头设置为“application/json”，Content-Type头设置为“text/xml”，如下图所示。 这就是Spring Restful web服务示例，支持XML和JSON。你可以看到扩展Spring框架有多么容易，这是Spring框架受欢迎的主要原因之一。