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>          <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