I need to generate a file that consolidates all the json results of each feature execution

I need to generate a file that consolidates all the results of each feature execution?

karate-dsl generates the test results in a JSON file for each of the executed feature files.

... so I created a utility that allows me to do it in Java.

I invite you to read the README https://github.com/jesusop/karate-cucumber-xray

The method reads all the json result files generated by karate and unifies them into a single cucumber.json file

You can aslo modify the paths of the files:

private static final String JSON_DIRECTORY = "/cucumber-html-reports";
private static final String CUCUMBER_JSON = "/cucumber.json";

private static void writeResultsToOneFile(JSONArray totalResults) throws IOException {
        File currentDirectory = new File((new File(".")).getAbsolutePath());
        String absolutePath = currentDirectory.getCanonicalPath();

        File directory = new File(absolutePath + "/" + TARGET_DIRECTORY + JSON_DIRECTORY);
        if (!directory.exists()) {
            directory.mkdirs();
        }

        File cucumberJsonFile = new File(directory + CUCUMBER_JSON);
        try (FileWriter fileWriter = new FileWriter(cucumberJsonFile)) {
            fileWriter.write(totalResults.toJSONString());

        }

        logger.info("cucumber.json file has been created at: " + cucumberJsonFile.getAbsolutePath());
    }

Note that upon completion of the tests, you will receive a message like this:

INFO: cucumber.json file has been created at: ...\karate-cucumber-xray\target\cucumber-html-reports\cucumber.json

Finally you can use the cucumber.json file and use it for example in the Jira Xray API.