How to convert JSON object using GSON in Java?

Question

Here is the JSON string return from API:

   {"id":1,"bps_id":"C199","summary":{"as_of_date":"2017-06-20","bp_earned":0,"bp_balance":"199400","bp_redeemed":"600"},"bps_message":{"eng":"mobile testing message","chi":"mobile testing message chi"},"bps_image":"https:\/\/mydomain.com\/images\/eng\/promotion\/C199_MH.gif","error_message":{"eng":"","chi":""},"error_flags":""}

And I have created an object for this:

public class SummaryResponse {

    String bps_id;
    String bps_image;
    String bps_message;
    String as_of_date;
    String bp_earned;
    String bp_redeemed;
    String bp_balance;

    public String getBps_image() {
        return bps_image;
    }

    public LangResponse getBps_message() {
        return bps_message;
    }

    public String getAs_of_date() {
        return as_of_date;
    }

    public String getBp_earned() {
        return bp_earned;
    }

    public String getBp_redeemed() {
        return bp_redeemed;
    }

    public String getBp_balance() {
        return bp_balance;
    }
}

It does not convert as expert, as there is some JSON object inside the string, how to convert that as well? Thanks for helping.

Answer 1

You can create like this,

public class SummaryResponse {

    public String id;
    public String bps_id;

    public Summary summary;
    public Message bps_message;
    public String bps_image;
    public Message error_message;
    public String error_flags;

    class Summary {
        public String as_of_date;
        public int bp_earned;
        public String bp_balance;
        public String bp_redeemed;
    }

    class Message {
        public String eng;
        public String chi;
    }
}

you can call like this.

SummaryResponse summaryResponse = new Gson().fromJson([Your Json], SummaryResponse.class);  

Answer 2

This a quick simple way to parse an array of Objects and also a single object it works for me when I am parsing json.

I believe it will only work as long as the json object is well formatted. I haven't experimented with a ill-formatted json object but that is because the api it request from was build by me, so I haven't had to worry about that

        Gson gson = new Gson();
    SummaryResponse[] data = gson.fromJson(jsonObj, SummaryResponse[].class);