4nakama

Want to serve JSON from one of your spring-mvc controller ?

This is how to do it in 3 steps!

1- Download Jackson JSON processor here :  http://jackson.codehaus.org/

If you’re using maven, add this dependency to you pom.xml :

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-jaxrs</artifactId>
    <version>1.8.5</version>
</dependency>

Be sure jackson is in your classpath.

2- Add the mvc context and the mvc:annotation-driven in your servlet configuration file (in my case : dispatcher-servlet.xml) :

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-3.0.xsd

http://www.springframework.org/schema/mvc

        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- To serve JSON -->
    <mvc:annotation-driven/>    

    <context:annotation-config />

    <!-- Scan for controller -->
    <context:component-scan base-package="net.nakama.example.controller"/>

    <bean id="viewResolver"
	class="org.springframework.web.servlet.view.UrlBasedViewResolver">
	<property name="viewClass"
		value="org.springframework.web.servlet.view.JstlView" />
	<property name="prefix" value="/WEB-INF/jsp/" />
	<property name="suffix" value=".jsp" />
    </bean>

</beans>

3- Write a simple controller. This controller must contain a method with a proper @RequestMapping tag. This method must return the object your want to “serialize” as JSON and must contain the tag @RequestBody :

package net.nakama.example.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import net.nakama.example.datamodel.Foo;

@Controller
public class JsonExampleController {

	@RequestMapping(value = "/getfoo/{name}")
	public @ResponseBody Foo getFoo(@PathVariable String name) {
		Foo foo = new Foo();
		foo.setBar(name);

		return foo;
	}
}

Enjoy!!!

Resources:

http://static.springsource.org/spring/docs/current/spring-framework-reference/html/mvc.html

http://blog.springsource.com/2010/01/25/ajax-simplifications-in-spring-3-0/

http://wiki.fasterxml.com/JacksonDocumentation