Add a new property to a specific json node using gson

问题

I am exploring gson and wanted to check if I can remove and add elements. I have the below json

{
  "header": {
"timeStamp": "2016-02-09T15:22:36.107-08:00",
"uniqueid": "321ef660",
},
"body": {
"search": {
  "searchId": 9206422282,
      "DateFrom": "2016-04-15T00:00:00-07:00",
      "DateTo": "2016-06-24T00:00:00-07:00"
    }
  },
  "amount": [
    {   
        "amount": 73.704285,
        "currency": "USD"
      },
      "amountagain": {
        "amount": 96.791435,
        "currency": "USD"
      },
      "winners": null,
      "pgoodId": null,
      },

and now I want to add a new element under body like :

{
"header": {
"timeStamp": "2016-02-09T15:22:36.107-08:00",
"uniqueid": "321c5690-1d2e-4403-9c31-029cc47ef660",
},
"body": {
"search": {
  "searchId": 9206422282,
      "DateFrom": "2016-04-15T00:00:00-07:00",
      "DateTo": "2016-06-24T00:00:00-07:00"
      "AddANewFieldHere" : **"2016-04-18"**
    }
  }

when I do

JsonObject jsonObject = new JsonObject();
    try {
        JsonParser parser = new JsonParser();
        JsonElement jsonElement = parser.parse(new FileReader("src/main/resources/search.json"));
        jsonObject = jsonElement.getAsJsonObject();
    } catch (FileNotFoundException e) {

    } catch (IOException ioe){

    }

//    jsonObject.get("checkin");
jsonObject.addProperty("AddANewFieldHere","2016-04-18");
    System.out.print(jsonObject);

}

It adds this property at the end of the document not as I expect under body.

回答1:

jsonObject is the root node. You need to navigate to the node you want to modify.

JsonObject body = jsonObject.getAsJsonObject("body");
body.addProperty("AddANewFieldHere","2016-04-18");

From the example output, it looks like want it under the path body/search/searchId not body though:

JsonObject searchId = jsonObject
                .getAsJsonObject("body")
                .getAsJsonObject("search")
                .getAsJsonObject("searchId");
searchId.addProperty("AddANewFieldHere","2016-04-18");

来源：https://stackoverflow.com/questions/36688365/add-a-new-property-to-a-specific-json-node-using-gson

标签

java

json

gson