Spring 3 MVC and JSON example

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

Technologies used :

Spring 3.2.2.RELEASE

Jackson 1.9.10

JDK 1.6

Eclipse 3.6

Maven 3

P.S In Spring 3, to output JSON data, just puts Jackson library in the project classpath.

1. Project Dependencies

Get Jackson and Spring dependencies.

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.mkyong.common</groupId>
<artifactId>SpringMVC</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>SpringMVC Json Webapp</name>
<url>http://maven.apache.org</url>

<properties>
<spring.version>3.2.2.RELEASE</spring.version>
<jackson.version>1.9.10</jackson.version>
<jdk.version>1.6</jdk.version>
</properties>

<dependencies>

<!-- 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>

<!-- Jackson JSON Mapper -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>${jackson.version}</version>
</dependency>

</dependencies>

<build>
<finalName>SpringMVC</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
<wtpversion>2.0</wtpversion>
</configuration>
</plugin>
<
4000
plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
</plugins>
</build>

</project>

2. Model

A simple POJO, later output this object as formatted JSON data.

package com.mkyong.common.model;

public class Shop {

String name;
String staffName[];

//getter and setter methods

}

3. Controller

Add

@ResponseBody

as return value. Wen Spring sees

Jackson library is existed in the project classpath

The

mvc:annotation-driven

is enabled

Return method annotated with

@ResponseBody

Spring will handle the JSON conversion automatically.

JSONController.java

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.

mvc-dispatcher-servlet.xml

<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