json path expression to get root key

Question

I have this json:

{
    "-1":     {
        "description": "test1"
    },
    "222":     {
        "description": "test2"
    },
    "223":     {
        "description": "test3"
    },
    "224":     {
        "description": "test4"
    },
    "recordsCount": 4
}

Using this Json path expression: $.. it returns all the Json. I would like to find the Json path expression that returns only the ID values: "-1" "222" "223" "224"

Can you help me?

you need to provide more details or code snippet about your question or query. So that others may understand your questions and efforts more clearly to answer your questions more clearly — Rakesh Hiray, Jun 10 '20 at 13:36

wp78de · Answer 1 · 2020-11-15T23:09:27.843

Accessing the property (key) instead of the value is a feature not present in the original JSONPath specifications, and only a few implementation support this feature. So, no luck using the JMeter JsonPath Plugin/Extractor extracting only property names.
_{For instance, JsonPath-Plus for JavaScript offers the operator ~ for grabbing property names of matching items.}

As an alternative, you could use JSR223 Groovy to get the results from JSON:

import groovy.json.JsonSlurper;
import groovy.json.JsonOutput; //if output as JSON is needed

JsonSlurper JSON = new JsonSlurper ();
jsonResponse = JSON.parseText(prev.getResponseDataAsString());
//println json.keySet() //[-1, 222, 223, 224, recordsCount]
vars.put("firstName", response.members[2].firstName.toString());
Set<String> keySet=obj.keySet();
List<String> keys = [];
// iterate over the key set, adding only numbers to result list
for(String key:keySet){
    if(key.isNumber())
        keys.add(key);
}
//println(keys); //[-1, 222, 223, 224]
def output = JsonOutput.toJson(keys); //convert to JSON string if neede
//println(output); //["-1","222","223","224"]
vars.put("jsonKeys", output.toString());

Demo: Online Groovy sample.

More information:

How to extract data from JSON response using JMETER (See 8.3 JSR223 with Groovy)
Scripting JMeter Assertions in Groovy - A Tutorial
Jayway JsonPath (alternative Java JSONPath library)

@sarjaana It looks like you could use Groovy to do this. See the updated answer. — wp78de, Nov 15 '20 at 23:10

json path expression to get root key

1 Answers1