Converting JSON to JSONLD

I am trying to convert JSON to RDF graphs. For this, I have to initially
convert JSON to JSONLD. I am trying to do this by using JSONLD-JAVA
<https://github.com/jsonld-java/jsonld-java>. The problem is that I get
only empty object as result. I know that I can add a @context annotation
manually for small and simple JSON models, which works for very simple JSON
files, but I have to work with quite big JSON models like this
<https://github.com/iliriani/iliriangit/blob/master/CustomerForm.form%20(1).xml>
which
can not be converted only by adding a context.

Here is my java code:

   String file = "C:\\Users\\Admin\\Desktop\\Forms\\test\\stack.json";

        // Open a valid json(-ld) input file
        InputStream inputStream = new FileInputStream(file);

        Object jsonObject = JsonUtils.fromInputStream(inputStream);
        // Create a context JSON map containing prefixes and definitions
        Map context = new HashMap();
        System.out.println(jsonObject);

        // Create an instance of JsonLdOptions with the standard JSON-LD options
        JsonLdOptions options = new JsonLdOptions();

        //Convert to JSONLD
        Object compact = JsonLdProcessor.compact(jsonObject, context,
options);//      System.out.println("Compact is: "+compact);//
Object compact = JsonLdProcessor.compact(jsonObject, new HashMap<>(),
new JsonLdOptions());

        // Print out the result (or don't, it's your call!)
        System.out.println(JsonUtils.toPrettyString(compact));}

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Hope for any help to convert JSON to JSONLD from your side. Thanks a lot.