How to convert HTTP Request Body into JSON Object in Java

Question

I am trying find a Java lib/api that will allow me to turn the contents of a HTTP Request POST body into a JSON object.

Ideally I would like to use a Apache Sling library (as they are exposed in my container naturally).

The closest I've found it: org.apache.sling.commons.json.http which converts the header to JSON.

HTTP Post bodies are in the format; key1=value1&key2=value2&..&keyn=valueN so I assume there is something out there, but I havent been able to find it.

I may just have to use a custom JSONTokener (org.apache.sling.commons.json.JSONTokener) to do this if something doesn't already exist. Thoughts?

Thanks

Answer 1

Assuming you're using an HttpServlet and a JSON library like json-simple you could do something like this:

public JSONObject requestParamsToJSON(ServletRequest req) {
  JSONObject jsonObj = new JSONObject();
  Map<String,String[]> params = req.getParameterMap();
  for (Map.Entry<String,String[]> entry : params.entrySet()) {
    String v[] = entry.getValue();
    Object o = (v.length == 1) ? v[0] : v;
    jsonObj.put(entry.getKey(), o);
  }
  return jsonObj;
}

With example usage:

public void doPost(HttpServletRequest req, HttpServletResponse res) {
  JSONObject jsonObj = requestParamsToJSON(req);
  // Now "jsonObj" is populated with the request parameters.
  // e.g. {"key1":"value1", "key2":["value2a", "value2b"], ...}
}

Answer 2

import org.json.JSONObject;

 JSONObject json = new JSONObject(request.getParameterMap())

Answer 3

Jackson is also a good option - its used extensively in Spring. Here is the tutorial: http://wiki.fasterxml.com/JacksonInFiveMinutes

Answer 4

I recommend trying Apache Commons Beanutils.

ServeltRequest request;

Map map = request.getParameterMap();
MyObject object = new MyObject();
BeanUtils.populate(object, map);
String json = object.toJSON() //using any JSON library

Answer 5

Sorry on making this an own answer but obviously my reputation doesn't allow me to simply add a comment to the answer How to convert HTTP Request Body into JSON Object in Java of maerics.

I would also iterate over the request params but instead of using an arbitrary json library use the JSONObject that is provided by sling. http://sling.apache.org/apidocs/sling6/org/apache/sling/commons/json/JSONObject.html

Answer 6

Use Gson. With this you can create class with private variables which represent the data you want : for example.

meta:{
       name:"Example"
       firstname:"Example2"
     }
data:[
      {
        title:"ecaetra"
        description:"qwerty"
      }
      ...
     ]

Json Object could be retrieve like this :

public class RetrieveData {

      private Meta meta;
      private List<Data> data;

      public Meta getMeta(){
            return meta;
      }

      public List<Data> getData(){
            return data;
      }
}

public class Meta {

      private String name;
      private String firstname;

      public String getName(){
            return name;
      }

      public String getFirstName(){
            return firstname;
      }

}

public class Data {

      private String title;
      private String description;

      public String getTitle(){
            return title;
      }

      public String getDescription(){
            return description;
      }

}

And your instruction are simple. Content is the content of your Page, you can retrieve it with Asynctask.

 Object o = new Gson().fromJson(Content, RetrieveData.class);
 data = (RetrieveData)o;
 // Get Meta
    data.getName(); // Example
    data.getFirstName(); // Example2
 // Get Data
    data.get(0).getTitle(); // position 0 : ecaetra
    data.get(0).getDescription(); // position 0 : qwerty