How to use jsonpath in GSON

Question

I'm getting to grips with GSON for JAVA and have a question about how to make jsonpath like selections from the large json documents I'm working with.

For example with a json document like:

{
  "environment": {
    "red": {
      "area": {
        "1": {
          "name": "foo"
        },
        "2": {
          "name": "bar"
        }
      }
    }
  }
}

The jsonpath expression of:

   $.environment.red.area

Returns:

 [
  {
    "1": {
      "name": "foo"
    },
    "2": {
      "name": "bar"
    }
  }
]

How can this selection be achieved in GSON?

The answer given to the question for which this question is flagged as a duplicate is not clear to me. It seems to say that it CAN be done in GSON but does not say or show how (as far as I can tell).

Possible duplicate of [Jsonpath with Jackson or Gson](https://stackoverflow.com/questions/34111276/jsonpath-with-jackson-or-gson) — jsalonen, Aug 06 '17 at 09:19
The answer given to the question for which this question is flagged as a duplicate is not clear to me. It seems to say that it CAN be done in GSON but does not say or show how (as far as I can tell). — Indrid, Aug 06 '17 at 09:31
Then read it again. It contains an example, along with a link to the relevant documentation, showing how to use Jackson or Gson to parse and map the JSON. — JB Nizet, Aug 06 '17 at 09:34
@JBNizet You are so kind. The other question contains an uncontested response stating that jsonpath is not supported in GSON then goes on to talk about Jayway. If there is a clear example of using GSON to perform jsonpath selections in that answer then it continues to elude me. — Indrid, Aug 06 '17 at 09:41
If you want to use jsonpath selection, GSON is not what you're looking for. GSON is a JSON mapper. But JsonPath allows doing JsonPath selections. And it can use GSON to parse and map your JSON. — JB Nizet, Aug 06 '17 at 09:54
Thanks for clarifying :-) Much appreciated. Looking into JayWay now... it could be the ideal solution. — Indrid, Aug 06 '17 at 09:57

score 4 · Answer 1 · edited Feb 12 '19 at 09:19

You may use the code below..

public static String getJsonStringForPath(String strJson, String strJPath)
    {
        Configuration JACKSON_JSON_NODE_CONFIGURATION = Configuration.builder().jsonProvider(new GsonJsonProvider())
                .options(Option.ALWAYS_RETURN_LIST, Option.SUPPRESS_EXCEPTIONS).build();

        Configuration conf = Configuration.builder().jsonProvider(new GsonJsonProvider())
                .options(Option.ALWAYS_RETURN_LIST, Option.SUPPRESS_EXCEPTIONS).build();

        JsonArray objArrJ = JsonPath.using(conf).parse(strJson).read(strJPath);     
        String strRetJson = ""+objArrJ;
        return strRetJson;
    }

//Pass the param of  JsonPath : "$.environment[*].red"

Refer to documentation: of jsonpath : https://github.com/json-path/JsonPath

How to use jsonpath in GSON

1 Answers1