How to read json sent by ajax in servlet

You won't be able to parse it on the server unless you send it properly:

$.ajax({    type: 'get', // it's easier to read GET request parameters    url: 'masterpaket',    dataType: 'JSON',    data: {       loadProds: 1,      test: JSON.stringify(test) // look here!    },    success: function(data) {    },    error: function(data) {        alert('fail');    }});

You must use JSON.stringify to send your JavaScript object as JSON string.

And then on the server:

String json = request.getParameter("test");

You can parse the json string by hand, or using any library (I would recommend gson).

You will have to use the JSON parser to parse the data into the Servlet

import org.json.simple.JSONObject;// this parses the jsonJSONObject jObj = new JSONObject(request.getParameter("loadProds")); Iterator it = jObj.keys(); //gets all the keyswhile(it.hasNext()){    String key = it.next(); // get key    Object o = jObj.get(key); // get value    System.out.println(key + " : " +  o); // print the key and value}

You will need a json library (e.g Jackson) to parse the json

Using the import org.json.JSONObject instead of import org.json.simple.JSONObject did the trick for me.

See How to create Json object from String containing characters like ':' ,'[' and ']' in Java.