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