Passing JSON Map into Spring MVC Controller

Question

I'm trying to send a JSON representation of a Map into my controller as a POST parameter.

@RequestMapping(value = "/search.do", method = RequestMethod.GET, consumes = { "application/json" })
public @ResponseBody Results search(@RequestParam("filters") HashMap<String,String> filters, HttpServletRequest request) {
       //do stuff
}

I found that @RequestParam would just throw a 500 error, so I tried using @ModelAttribute instead.

@RequestMapping(value = "/search.do", method = RequestMethod.GET, consumes = { "application/json" })
public @ResponseBody Results search(@ModelAttribute("filters") HashMap<String,String> filters, HttpServletRequest request) {
       //do stuff
}

This would correctly respond to requests, but I realized that the Map was empty. With later experimentation, I found that any object (not just HashMap) would be instantiated, but no fields would be filled in. I do have Jackson on my classpath, and my controllers will respond with JSON. However, it would appear that my current configuration is not allowing Spring to read JSON in via a GET/POST parameter.

How does one pass JSON representations of objects from a client-side AJAX request to a Spring controller as a request parameter and get a Java object out?

EDIT Adding my relevant Spring configuration

  <bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
    <property name="mediaTypes">
      <map>
        <entry key="html" value="text/html" />
        <entry key="json" value="application/json" />
      </map>
    </property>
    <property name="viewResolvers">
      <list>
        <bean class="org.springframework.web.servlet.view.UrlBasedViewResolver">
          <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
          <property name="prefix" value="/WEB-INF/jsp/" />
          <property name="suffix" value=".jsp" />
        </bean>
      </list>
    </property>
    <property name="defaultViews">
      <list>
        <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
          <property name="prefixJson" value="true" />
        </bean>
      </list>
    </property>
  </bean>
  <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
    <property name="messageConverters">
      <list>
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
      </list>
    </property>
  </bean>

On the suggestion of a commenter, I tried @RequestBody. This will work, so long as the JSON strings are quoted with double quotes.

@RequestMapping(value = "/search.do", method = RequestMethod.POST, consumes = { "application/json" })
public @ResponseBody Results<T> search(@RequestBody HashMap<String,String> filters, HttpServletRequest request) {
      //do stuff
}

This does solve my immediate issue, but I'm still curious as to how ou might pass in multiple JSON objects via an AJAX call.

Did you have the MappingJacksonJsonView bean on yours spring-context.xml? — Deividi Cavarzan, Mar 28 '13 at 14:55
How are you posting the data, as part of a form, ajax request? — clav, Mar 28 '13 at 14:55
@DeividiCavarzan I do have MappingJacksonJsonView in my context. I am sending this data as an AJAX request. I have tried doing it as GET and POST, to the same effect. — monitorjbl, Mar 28 '13 at 15:06
Check out this question/answer: http://stackoverflow.com/questions/12475911/requestbody-sent-through-spring-mvc-json-jackson-processor — Sotirios Delimanolis, Mar 28 '13 at 15:31
@SotiriosDelimanolis I have tried RequestBody, and it causes a 400 error whenever the POSTed content has anything. — monitorjbl, Mar 28 '13 at 15:54
@monitorjbl Can you update your configuration above? 400 can mean your handler method can't be invoked because it can't find the parameters it needs. — Sotirios Delimanolis, Mar 28 '13 at 15:56
@SotiriosDelimanolis I tried again, and I realized that the single quotes were causing the problem with RequestBody. I've updated my question. — monitorjbl, Mar 28 '13 at 17:55
@monitorjbl One json string contains many json objects, so what's the problem? — Sotirios Delimanolis, Mar 28 '13 at 17:56
@SotiriosDelimanolis Because that means I will need to make a separate wrapper class anytime I want a different combination of objects. That's a really clunky solution to this, it would really make more sense to find a way to get Spring to convert objects passed in as RequestParams — monitorjbl, Mar 28 '13 at 18:22
This is my question can someone help http://stackoverflow.com/questions/16409036/springmvc-ajax-request-looking-for-conversion-strategy — devdar, May 07 '13 at 03:27

score 7 · Answer 1 · edited Jun 20 '18 at 19:44

This does solve my immediate issue, but I'm still curious as to how ou might pass in multiple JSON objects via an AJAX call.

The best way to do this is to have a wrapper object that contains the two (or multiple) objects you want to pass. You then construct your JSON object as an array of the two objects i.e.

[
  {
    "name" : "object1",
    "prop1" : "foo",
    "prop2" : "bar"
  },
  {
    "name" : "object2",
    "prop1" : "hello",
    "prop2" : "world"
  }
]

Then in your controller method you recieve the request body as a single object and extract the two contained objects. i.e:

@RequestMapping(value="/handlePost", method = RequestMethod.POST, 
                consumes = {      "application/json" })
public void doPost(@RequestBody WrapperObject wrapperObj) { 
     Object obj1 = wrapperObj.getObj1;
     Object obj2 = wrapperObj.getObj2;

     //Do what you want with the objects...


}

The wrapper object would look something like...

public class WrapperObject {    
private Object obj1;
private Object obj2;

public Object getObj1() {
    return obj1;
}
public void setObj1(Object obj1) {
    this.obj1 = obj1;
}
public Object getObj2() {
    return obj2;
}
public void setObj2(Object obj2) {
    this.obj2 = obj2;
}   

}

Thanks for the RequestBody answer. I had a Map in my request, but it would always be empty, making the response empty too. Now RequestBody in front of the Map fixed it! — Aliya, Jun 16 '16 at 17:53

score 2 · Answer 2 · answered Mar 31 '14 at 12:24

You may use the Jackson library to convert from Json to Map.

@web-context.xml

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

@maven dependencies:

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-lgpl</artifactId>
    <version>1.9.13</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-lgpl</artifactId>
    <version>1.9.13</version>
</dependency>

@Controller

@RequestMapping(value = "/method", method = RequestMethod.DELETE)
public String method(
                @RequestBody Map<String, Object> obj){

@Request (e.g. jquery Ajax)

$.ajax({"type": "DELETE",
        "contentType": "application/json;",
        "url": "/method",
        "data": JSON.stringify({"key": "Ricardo"}),
        "dataType": "json";}
});

It's much easier with Python Frameworks or Play! ufff

Jackson 1.9.x is in maintenance mode; I'd suggest Jackson 2.3.x instead. — Emerson Farrugia, Mar 31 '14 at 12:30

Sanchi Girotra · Answer 3 · 2017-03-07T04:34:04.753

I have passed the Map object to Java using below code :

Javascript Code :

var values = {
                    "object1" : JSON.stringify(object1),
                    "object2" : JSON.stringify(object2)
            };
 var response = $http.post(url,data);

Server Side Code :

@RequestMapping(value = "/deleteData",method = RequestMethod.POST,consumes = MediaType.APPLICATION_JSON_VALUE)
    @ResponseBody
    public Result deleteData(@RequestBody HashMap<String, Object> dataHashMap) {
    Object1 object1=  (Object1) JsonConvertor.jsonToObject((String) dataHashMap.get("object1"), Object1.class);
        Object2 object2= (Object2) JsonConvertor.jsonToObject((String) dataHashMap.get("object2"), Object2.class);   
}

JsonConvertor Class :

public class JsonConvertor {
  public static <T> Object jsonToObject(String json, Class<T> clazz) {
    if (json == null)
      throw new IllegalArgumentException("null cannot be converted to Object");
    Gson gson = new GsonBuilder().disableHtmlEscaping().setDateFormat("dd-MMM-yyyy").create();
    return gson.fromJson(json, clazz);
  }
}

You forgot to say what `JsonConvertor` is. – kryger Mar 06 '17 at 16:25 — kryger, Mar 06 '17 at 16:25
Edited the solution as suggested – Sanchi Girotra Mar 07 '17 at 04:34 — Sanchi Girotra, Mar 07 '17 at 04:34

score 0 · Answer 4 · edited May 23 '17 at 10:31

You are not getting json correctly.

Do like that ....

/*
 * Mapping for Demographics And Profiling Question Filter
 */
@RequestMapping (value = "/generalFilter")
public void ageFilteration(@RequestParam Map <String,String> filterParams,HttpServletRequest request,HttpServletResponse response) throws IOException
{
    //  System.out.println("Geographies in Controller :"+ filterParams.get("geographies"));
    List<FeasibilityBean> feasibilityList = feasibilityDao.getGeneralFeasibilityList(filterParams,request);
    //  System.out.println(" General Filter List Size:"+feasibilityList.size());
    response.getWriter().print(new Gson().toJsonTree(feasibilityList,new TypeToken<List<FeasibilityBean>>(){}.getType()));
}

}

Js Code

var ages='',ageCond='',genders='',genderCond='';

    $.ajax({
        type: "POST",
        url : url,
        data : {ages:ages,ageCond:ageCond,genders:genders,genderCond:genderCond},
        beforeSend: function() { 
            $(thisVar).find('i').addClass('fa-spin');
        },
        success : function(feasibilityJson){ 

        },
        error : function(data) {
            alert(data + "error");
        },
        complete:function(){  
            $(thisVar).find('i').removeClass('fa-spin');
        }
    });

or you want to bind bean with json....

https://stackoverflow.com/a/21689084/5150781 https://stackoverflow.com/a/37958883/5150781

score 0 · Answer 5 · answered May 07 '17 at 14:43

    @RequestMapping(method = RequestMethod.POST)
    public HttpEntity<Resource<Customize>> customize(@RequestBody String customizeRequest) throws IOException {
       Map<String, String> map = mapper.readValue(customizeRequest, new TypeReference<Map<String,String>>(){});
       log.info("JSONX: " + customizeRequest);
       Long projectId_L = Long.parseLong(map.get("projectId"));
       [...]

score 0 · Answer 6 · answered Oct 12 '18 at 10:23

As @dario's answer, but for Jackson 2 version:

spring-web-context.xml

    <bean id="messageAdapter" class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" >
            <property name="supportedMediaTypes">    
                <list>    
                    <value>application/json;charset=utf-8</value>    
               </list>    
            </property>  
            </bean>
        </list>
    </property>
</bean>

maven pom.xml:

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.6</version>
    </dependency>

java controller

@RequestMapping(value = "/search.do", method = RequestMethod.GET, consumes = { "application/json" })
public @ResponseBody Results search(@RequestBody Map<String,Object> filters, HttpServletRequest request) {

Passing JSON Map into Spring MVC Controller

6 Answers6

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