JQuery, Spring MVC @RequestBody and JSON - making it work together

I'm pretty sure you only have to register MappingJacksonHttpMessageConverter

(the easiest way to do that is through <mvc:annotation-driven /> in XML or @EnableWebMvc in Java)

See:

• this forum post and
• 7.6.5 Configuring Formatting in Spring MVC

Here's a working example:

Maven POM

<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>test</groupId><artifactId>json</artifactId><packaging>war</packaging>    <version>0.0.1-SNAPSHOT</version><name>json test</name>    <dependencies>        <dependency><!-- spring mvc -->            <groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>3.0.5.RELEASE</version>        </dependency>        <dependency><!-- jackson -->            <groupId>org.codehaus.jackson</groupId><artifactId>jackson-mapper-asl</artifactId><version>1.4.2</version>        </dependency>    </dependencies>    <build><plugins>            <!-- javac --><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId>            <version>2.3.2</version><configuration><source>1.6</source><target>1.6</target></configuration></plugin>            <!-- jetty --><plugin><groupId>org.mortbay.jetty</groupId><artifactId>jetty-maven-plugin</artifactId>            <version>7.4.0.v20110414</version></plugin>    </plugins></build></project>

in folder src/main/webapp/WEB-INF

web.xml

<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"    version="2.4">    <servlet><servlet-name>json</servlet-name>        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>        <load-on-startup>1</load-on-startup>    </servlet>    <servlet-mapping>        <servlet-name>json</servlet-name>        <url-pattern>/*</url-pattern>    </servlet-mapping></web-app>

json-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"    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.xsd">    <import resource="classpath:mvc-context.xml" /></beans>

in folder src/main/resources:

mvc-context.xml

<beans xmlns="http://www.springframework.org/schema/beans"    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns:context="http://www.springframework.org/schema/context"    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd        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">    <mvc:annotation-driven />    <context:component-scan base-package="test.json" /></beans>

In folder src/main/java/test/json

TestController.java

@Controller@RequestMapping("/test")public class TestController {    @RequestMapping(method = RequestMethod.POST, value = "math")    @ResponseBody    public Result math(@RequestBody final Request request) {        final Result result = new Result();        result.setAddition(request.getLeft() + request.getRight());        result.setSubtraction(request.getLeft() - request.getRight());        result.setMultiplication(request.getLeft() * request.getRight());        return result;    }}

Request.java

public class Request implements Serializable {    private static final long serialVersionUID = 1513207428686438208L;    private int left;    private int right;    public int getLeft() {return left;}    public void setLeft(int left) {this.left = left;}    public int getRight() {return right;}    public void setRight(int right) {this.right = right;}}

Result.java

public class Result implements Serializable {    private static final long serialVersionUID = -5054749880960511861L;    private int addition;    private int subtraction;    private int multiplication;    public int getAddition() { return addition; }    public void setAddition(int addition) { this.addition = addition; }    public int getSubtraction() { return subtraction; }    public void setSubtraction(int subtraction) { this.subtraction = subtraction; }    public int getMultiplication() { return multiplication; }    public void setMultiplication(int multiplication) { this.multiplication = multiplication; }}

You can test this setup by executing mvn jetty:run on the command line, and then sending a POST request:

URL:        http://localhost:8080/test/mathmime type:  application/jsonpost body:  { "left": 13 , "right" : 7 }

I used the Poster Firefox plugin to do this.

Here's what the response looks like:

{"addition":20,"subtraction":6,"multiplication":91}

In Addition you also need to be sure that you have

 <context:annotation-config/> 

in your SPring configuration xml.

I also would recommend you to read this blog post. It helped me alot.Spring blog - Ajax Simplifications in Spring 3.0

Update:

just checked my working code where I have @RequestBody working correctly.I also have this bean in my config:

<bean id="jacksonMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"><property name="messageConverters">  <list>    <ref bean="jacksonMessageConverter"/>  </list></property></bean>

May be it would be nice to see what Log4j is saying. it usually gives more information and from my experience the @RequestBody will fail if your request's content type is not Application/JSON. You can run Fiddler 2 to test it, or even Mozilla Live HTTP headers plugin can help.

In addition to the answers here...

if you are using jquery on the client side, this worked for me:

Java:

@RequestMapping(value = "/ajax/search/sync") public String sync(@RequestBody Foo json) {

Jquery (you need to include Douglas Crockford's json2.js to have the JSON.stringify function):

$.ajax({    type: "post",    url: "sync", //your valid url    contentType: "application/json", //this is required for spring 3 - ajax to work (at least for me)    data: JSON.stringify(jsonobject), //json object or array of json objects    success: function(result) {        //do nothing    },    error: function(){        alert('failure');    }});