Spring API Produce JSON or XML - spring

Question

I need to create an API that can produce either XML or JSON.
So for example if the path requested is
/getData?format=XML
it should produce XML and if the path requested is
/getData?format=JSON
is should produce JSON.
I've gone through the Spring tutorial "Build a RESTful web service"
So I simply want to take that code and alter it so it will produce XML as well as JSON.
What are the steps I should take?

Answer 1

Step 1: Make sure you have Jackson 2 and Castor on the classpath for JSON and XML rendering respectively. If using Maven, these can be added as dependencies. You can also use GSON for JSON and JAXB for XML.
Step 2: Return a Java object from the controller method, something like:
#RequestMapping("/users")
public #ResponseBody Users all()
{
return ServiceLocator.findUserService().all();
}
Step 3: Configure the JSON and XML converters in the Spring application context file as follows:
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="prettyPrint" value="true" />
<property name="supportedMediaTypes" value="application/json" />
</bean>
<bean class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter">
<constructor-arg>
<bean class="org.springframework.oxm.castor.CastorMarshaller" />
</constructor-arg>
<property name="supportedMediaTypes" value="application/xml" />
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
Step 4: Configure a ContentNegotiatingViewResolver in the Spring application context file as follows:
<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<property name="mediaTypes">
<map>
<entry key="json" value="application/json" />
<entry key="xml" value="application/xml" />
</map>
</property>
</bean>
Once these steps have been completed, different representations can be obtained in multiple ways:
XML
http://server/users.xml
http://server/users?format=xml
http://server/users with the HTTP header Accepts set to application/xml
JSON
http://server/users.json
http://server/users?format=json
http://server/users with the HTTP header Accepts set to application/json