Spring 3 MVC And JSON Example

In Spring 3, you can enable “mvc:annotation-driven” to support object conversion to/from JSON format, if Jackson JSON processor is existed on the project classpath.

In this tutorial, we show you how to output JSON data from Spring MVC.

Technologies used :

1. Spring 3.0.5.RELEASE
2. Jackson 1.7.1
3. JDK 1.6
4. Eclipse 3.6
5. Maven 3

1. Project Dependencies

To use JSON in Spring MVC, you need to include Jackson dependency.

     < properties >
         < spring.version >3.0.5.RELEASE </ spring.version >
     </ properties >
 
     < dependencies >
 
         <!--  Jackson JSON Mapper  -->
         < dependency >
             < groupId >org.codehaus.jackson </ groupId >
             < artifactId >jackson-mapper-asl </ artifactId >
             < version >1.7.1 </ version >
         </ dependency >
 
         <!--  Spring 3 dependencies  -->
         < dependency >
             < groupId >org.springframework </ groupId >
             < artifactId >spring-core </ artifactId >
             < version >${spring.version} </ version >
         </ dependency >
 
         < dependency >
             < groupId >org.springframework </ groupId >
             < artifactId >spring-web </ artifactId >
             < version >${spring.version} </ version >
         </ dependency >
 
         < dependency >
             < groupId >org.springframework </ groupId >
             < artifactId >spring-webmvc </ artifactId >
             < version >${spring.version} </ version >
         </ dependency >
 

    </dependencies> 

2. Model

A simple POJO, later convert this object into JSON output.

package com.mkyong.common.model;
 
public  class Shop {
 
    String name;
    String staffName[];
 
     // getter and setter methods
 

} 

3. Controller

Add “@ResponseBody” in the return value, no much detail in the Spring documentation.

As i know, when Spring see

1. Jackson library existed on classpath
2. “mvc:annotation-driven” is enabled
3. Return method annotated with @ResponseBody

It will handle the JSON conversion automatically.

package com.mkyong.common.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.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.mkyong.common.model.Shop;
 
@Controller
@RequestMapping("/kfc/brands")
public  class JSONController {
 
    @RequestMapping(value="{name}", method = RequestMethod.GET)
     public @ResponseBody Shop getShopInJSON(@PathVariable String name) {
 
        Shop shop =  new Shop();
        shop.setName(name);
        shop.setStaffName( new String[]{"mkyong1", "mkyong2"});
 
         return shop;
 
    }
 

} 

4. mvc:annotation-driven

Enable “mvc:annotation-driven” in your Spring configuration XML file.

< beans  xmlns ="http://www.springframework.org/schema/beans"
    xmlns:context ="http://www.springframework.org/schema/context"
    xmlns:mvc ="http://www.springframework.org/schema/mvc"  
    xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
    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" >
 
     < context:component-scan  base-package ="com.mkyong.common.controller"   />
 
     < mvc:annotation-driven  />
 

</beans> 

5. Demo

URL : http://localhost:8080/SpringMVC/rest/kfc/brands/kfc-kampar

Download Source Code

Download it –  SpringMVC-JSON-Example.zip (7 KB)