Why JsonParser gives double quotes in the return value, using com.google.gson API

Question

I am currently using JsonObject and JsonParser of com.google.gson api (using gson-2.8.5 version) to parse and read the value form input JSON.

I have JSON filed like , smaple "resultCode":"SUCCESS", when I try to read the same value from json it gives the result as ""SUCCESS"" .

Every value I am reading, getting with double "" not sure why ? You can refer below screen of my debugging screen.

I am new to Json and parser, is that default behavior ?

I am expecting "SUCCESS", "S", "00000000" not like ""SUCCESS"" or ""S"" or ""00000000"" same I have highlighted in the below image .

Please share any idea how we can get apbsolute vlaue of string without """" double quote string it causing my string comparison fail.

String response_result = "{\"response\": {\"head\": {\"function\": \"acquiring.order.create\",\"version\": \"2.0\",\"clientId\": \"201810300000\",\"reqMsgId\": \"56805892035\",\"respTime\": \"2019-09-13T13:18:08+08:00\"},\"body\": {\"resultInfo\": {\"resultCode\": \"SUCCESS\",\"resultCodeId\": \"00000000\",\"resultStatus\": S,\"resultMsg\": \"SUCCESS\"},\"acquirementId\": \"2018080834569894848930\",\"merchantTransId\": \"5683668701112717398\",\"checkoutUrl\": \"http://localhost:8081/crm/operator/operator-search-init.action\"}},\"signature\":\"d+TUYLvt1a491R1e6aO8i9VwXWzVhfNgnhD0Du74f4RgBQ==\"}";
        HttpInvoker.Result result = i.new Result(200, response_result);
    JsonObject jo =  new JsonParser().parse(response_result).getAsJsonObject();

    String resultCode = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().get("resultCode").toString();
    String resultCodeId = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().get("resultCodeId").toString();
    String resultStatus = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().get("resultStatus").toString();
    String checkoutUrl = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("checkoutUrl").toString();

    if ( RESULT_CODE_GCASH_SUCCESS.equals(resultCode)
            && RESULT_STATUS_SUCCESS.equals(resultStatus)
            && StringUtils.isNotEmpty(checkoutUrl)) {

        log.error("Testing ".concat(resultCode).concat(resultStatus).concat(checkoutUrl));
    }
    log.error("Testing ".concat(resultCode).concat(resultStatus).concat(checkoutUrl));
    }

This is my input JSON

{ 
   "response":{ 
      "head":{ 
         "function":"acquiring.order.create",
         "version":"2.0",
         "clientId":"201810300000",
         "reqMsgId":"56805892035",
         "respTime":"2019-09-13T13:18:08+08:00"
      },
      "body":{ 
         "resultInfo":{ 
            "resultCode":"SUCCESS",
            "resultCodeId":"00000000",
            "resultStatus":"S",
            "resultMsg":"SUCCESS"
         },
         "acquirementId":"2018080834569894848930",
         "merchantTransId":"5683668701112717398",
         "checkoutUrl":"http://localhost:8081/crm/operator/operator-search-init.action"
      }
   },
   "signature":"d+TUYLvtI38YL2hresd98Ixu1BXccvvh1IQMiHuMXUEeW/N5exUsW491R1e6aO8i9VwXWzVhfNgnhD0Du74f4RgBQ=="
}

version of `gson` is? – Michał Krzywański Sep 14 '19 at 08:25 — Michał Krzywański, Sep 14 '19 at 08:25
I am using gson-2.8.5 version @michalk – Gautam Sep 14 '19 at 08:29 — Gautam, Sep 14 '19 at 08:29

Michał Krzywański · Answer 1 · 2019-09-14T08:41:48.680

5

JsonParser parses your json into JsonElement structure. The behaviour that you see is a normal since you are using toString method of JsonElement. To achieve your goal just use JsonElement::getAsString method :

String resultCode = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().get("resultCode").getAsString();

which gives SUCCESS instead of "SUCCESS"

Note that JsonElement is an abstract class and classes, that extend this class, will override those helper getAs... methods. In your case JsonPrimitive::getAsString will be invoked.

Also you could create a POJO class for your json and use Gson::fromJson to parse json into object of your POJO class.

edited Sep 14 '19 at 08:41

answered Sep 14 '19 at 08:31

Michał Krzywański

15,659
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but when i see API JsonElement::getAsString for public String getAsString() { throw new UnsupportedOperationException(this.getClass().getSimpleName()); } – Gautam Sep 14 '19 at 08:35
1

`JsonElement` is an abstract class and this method is overriden by subclasses. In your case it will be `JsonPrimitive::getAsString` that will be invoked. – Michał Krzywański Sep 14 '19 at 08:36
Yes now i am getting value without """ I am new to JSON is this correct way to read the value : -------------------------------------------- jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().getAsJsonPrimitive("resultCode").getAsString(); from above code snippet – Gautam Sep 14 '19 at 08:43
1

Yes it is correct. Both ways will work - yours and mine in the answer. I would also encourage you to look at `Gson::fromJson` and creating POJO class for your json. Then it would be easier for you to access the data from object of your POJO class. – Michał Krzywański Sep 14 '19 at 08:46
I understood, your point Gson :: fromJson it really smooth and neat way to access data in the JSAON. I will post the answer here. – Gautam Sep 15 '19 at 04:56
Bloody hell, this has been driving me crazy for the last 2 days. ... thanks – interstar Jul 18 '21 at 17:27

score 2 · Accepted Answer · answered Sep 15 '19 at 05:10

With the input from @Michalk: I understand that easy way to read JSON data is using Gson::fromJson and creating POJO class for out json.

I have generated POJO Classes supplying my sample input JSON using this link and Now I have POJO Classes called : CreateOrderJSONResponse

Gson::fromJson

Sample :

Gson gson = new Gson();
CreateOrderJSONResponse responseJson = gson.fromJson(inputJSON, CreateOrderJSONResponse.class);

Accessubg data :

    String resultCodeText =   responseJson.getResponse().getBody().getResultInfo().getResultCode();
    String resultCodeId =     responseJson.getResponse().getBody().getResultInfo().getResultCodeId();
    String resultStatus =     responseJson.getResponse().getBody().getResultInfo().getResultStatus();
    String checkoutUrl =      responseJson.getResponse().getBody().getCheckoutUrl();

Above Gson::fromJson example works smooth and it looks neat compare to direct accessing the filed with below sample code :

 JsonObject jo = parser.parse(inputJSON).getAsJsonObject();

 String resultCodeText = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().getAsJsonPrimitive("resultCode").getAsString();
 String resultCodeId = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().getAsJsonPrimitive("resultCodeId").getAsString();
 String resultStatus = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().get("resultInfo").getAsJsonObject().getAsJsonPrimitive("resultStatus").getAsString();
 String checkoutUrl = jo.get("response").getAsJsonObject().get("body").getAsJsonObject().getAsJsonPrimitive("checkoutUrl").getAsString();

Note : I have found this link of JSON or JAVA, SCALA, POJO generator tools as GitHub access you can access here

Why JsonParser gives double quotes in the return value, using com.google.gson API

2 Answers2