Spring MVC for json interaction

json data format is commonly used in interface calls and html pages. json format is simple and easy to parse.

• Request json, output json. It is not convenient for the front page to convert the requested content into json.
• Request key/value and output json. This method is commonly used.

Environmental preparation

Add dependency for json transformation

<!-- json Transformation-->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.7.2</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>1.9.13</version>
</dependency>

View dependency tree

[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.7.2:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.7.0:compile
[INFO] |  \- com.fasterxml.jackson.core:jackson-core:jar:2.7.2:compile
[INFO] \- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.13:compile
[INFO]    \- org.codehaus.jackson:jackson-core-asl:jar:1.9.13:compile

Configure the json converter

Add messageConverters to annotation adapter

<!--Annotation adapter -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
	<property name="messageConverters">
		<list>
			<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean>
		</list>
	</property>
</bean>

Note: if < MVC: annotation driven / > is used, the content above is not defined.

Input json string, output json string

Use jquery's ajax to submit json string and parse the output json results.

• jsp page

//Request json, the output is json
function requestJson(){
    $.ajax({
        type:'post',
        url:'${pageContext.request.contextPath }/requestJson.action',
        contentType:'application/json;charset=utf-8',
        //Data format is json string, commodity information
        data:'{"name":"Mobile phone","price":999}',
        //Return json result
        success:function(data){
            alert(data);
        }
    });
}

• controller

@RequestMapping("/requestJson")
public @ResponseBody ItemsCustom requestJson(@RequestBody ItemsCustom itemsCustom){
    return itemsCustom;
}

• @RequestBody converts the json string of the requested product information into an itemsCustom object
• @ResponseBody converts itemsCustom to json output

Enter key/value and the output is json string

Using jquery's ajax to submit the key/value string to parse the output json results

• jsp page

//Request key/value, the output is json
function responseJson(){
    $.ajax({
        type:'post',
        url:'${pageContext.request.contextPath }/responseJson.action',
        //The request is key/value. There is no need to specify contentType, because the default is key/value type
        //contentType:'application/json;charset=utf-8',
        //Data format is json string, commodity information
        data:'name=Mobile phone&price=999',
        //Return json result
        success:function(data){
            alert(data.name);
        }
    });
}

• controller

@RequestMapping("/responseJson")
public @ResponseBody ItemsCustom responseJson(ItemsCustom itemsCustom){
    return itemsCustom;
}