If you are struggling to arrange the "'s the correct syntax would be

String jsonRequestString = "{\"access_code\" : \""+code+"\" , ";

Instead of formatting Json string manually, which takes alot of effort, consider using a library or util.

For ex (going to use Jackson library) :

Request re = new Request();
re.setCode(code);
...
ObjectMapper mapper = new ObjectMapper();
String jsonStr = mapper.writeValueAsString(re);

If you don't want to directly convert your input to the expected Object you could create a JSONObject from your input like

JSONObject root = new JSONObject(input);

and then navigate from there exactly to the attribute you need e.g.:

root.getJSONArray("results").getJSONObject(0).getString("is_structured");

EDIT: (receive value under date)

root.getJSONArray("results").getJSONObject(0).getJSONObject("date").getString("value");

First, create a pojo class with different getter/setter for your required fields.

  public class MyResponse(){

    private List<String> idList;
    private List<String> nombreList;
    private List<String> descList;
    private List<String> califList;

    public void setIdList(List<String> list){
    this.idList = list;
    }

    public void getIdList(){
    return idList;
    }

    public void setNombreList(List<String> list){
    this.nombreList = list;
    }

    public void getNombreList(){
    return nombreList;
    }

    public void setDescList(List<String> list){
    this.descList = list;
    }

    public void getDescList(){
    return descList;
    }

    public void setCalifList(List<String> list){
    this.califList = list;
    }

    public void getCalifList(){
    return califList;
    }

}

Now parse each response and add in the list of MyResponse type

         public MyResponse getDataJSON(String response)
                    {
                        MyResponse myResponse = new MyResponse();
                        ArrayList<String> idList = new ArrayList<String>();
                        ArrayList<String> nombreList = new ArrayList<String>();
                        ArrayList<String> descList = new ArrayList<String>();
                        ArrayList<String> califList = new ArrayList<String>();

                        try
                        {
                            JSONArray jsonArray = new JSONArray(response);

                            for(int i=0; i<jsonArray.length(); i++)
                            {
                              idList.add(jsonArray.getJSONObject(i).getString("id"));

   nombreList.add(jsonArray.getJSONObject(i).getString("nombre"));
                              descList.add(jsonArray.getJSONObject(i).getString("descripcion"));
                              califList.add(jsonArray.getJSONObject(i).getString("calificacion"));
                            }

                            myResponse.setIdList(idList);
                            myResponse.setNombreList(nombreList);
                            myResponse.setDescList(descList);
                            myResponse.setCalifList(califList);

                            return myResponse;
                        }

                        catch (Exception e)
                        {
                            e.printStackTrace();
                        }

                        return list;
                    }

To retrieve back the data from getDataJSON()

     MyResponse myResponse = getDataJSON(new String(responseBody)));
     ArrayList<String> idList = myResponse.getIdList();
     ArrayList<String> nombreList = myResponse.getNombreList();
     ArrayList<String> descList = myResponse.getDescList();
     ArrayList<String> califList = myResponse.getCalifList();

I suggest to use one of many JSON processing libraries available.

Examples are Gson and Jackson.

Both of them allow to convert: json string <--> object

You should start with defining domain model:

public class Person {
   private String firstName;
   private String lastName;
   // getters/setters
}

Then you should do like this (for example, for GSON):

String json = "{\"firstName\":\"Jim\",\"lastName":\"Smith\"}";
Gson gson = new Gson();
Person person = gson.fromJson(json, Person.class);

Hope this helps

You have not escaped properly. You make sure you do:

var somejson = "{ \"key1\": \"val1\",\"key2\": \"value2\"}";

The easier way would be to just convert an existing object to a string using JSON.stringify(). Would recommend this as much as possible as there is very little chance of making a typo error.

var obj = {
    key1: "val1",
    key2: "value2"
};

var json = JSON.stringify(obj);

Your user name is stored in invitees Array so you need to replace that. For that, we can use JSONObject like below,

    String body = new String(Files
            .readAllBytes(Paths.get("src/test/resources/config/environments/sharePrivately.json")));
    JSONObject jsonObject = new JSONObject(body);
    jsonObject.put("invitees", new JSONArray("[{\"username\": \"[email protected]\",\"role\": \"VIEWER\"}]"));

In your code,

response = header.body(jsonObject.toString())
            .when()
            .post("/shares")
            .then()
            .assertThat()
            .extract()
            .response();

Output:

{
    "duration": "NO_EXPIRE",
    "invitees": [
        {
            "role": "VIEWER",
            "username": "[email protected]"
        }
    ],
    "invitationMessage": "",
    "type": "FILE",
    "items": [
        {
            "uuid": "shdy28-9b03-4c21-9c80-f96f31f9cee9",
            "projectId": "65ht8f99694454a658yef17a95e8f"
        }
    ]
}

You need to use below import,

    <dependency>
        <groupId>org.json</groupId>
        <artifactId>json</artifactId>
        <version>20160212</version>
    </dependency>

Using org.json library:

try {
     JSONObject jsonObject = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
}catch (JSONException err){
     Log.d("Error", err.toString());
}