Remove duplicates from JSON-like structure using Java [closed]

Input

{
    "email" : "[email protected]"
},{
    "email" : "[email protected]"
},{
    "email" : "[email protected]"
},{
    "email" : "[email protected]"
},

Expected output

{
    "email" : "[email protected]"
},{
    "email" : "[email protected]"
},

1. Remove duplicates

2. maintain format

3. appended last comma.

The problem is sometimes the input is not a proper JSON and also it's not sure that comma should be always present at the end. I need to remove only duplicate key value pairs from the input, the rest should remain the same.

I tried this way.

if (maxIndex > 0) {
    try {
        singleElementTemplate = dao.resolveObjectDataStringSinglePass(tmdtId, sourceTagHandle,
                maxIndex);

        String jsonText = singleElementTemplate.trim();

        if (!jsonText.startsWith("[") && !jsonText.endsWith("]")) {
            jsonText = "[" + jsonText + "]";
        }

        JSONArray jsonArr = new JSONArray(jsonText);

        Set<String> seen = new LinkedHashSet<>();
        JSONArray finalJsonArr = new JSONArray();

        for (int i = 0; i < jsonArr.length(); i++) {
            JSONObject obj = jsonArr.getJSONObject(i);
            if (seen.add(obj.toString())) {
                finalJsonArr.put(obj);
            }
        }

        StringBuilder formattedResult = new StringBuilder();
        for (int i = 0; i < finalJsonArr.length(); i++) {

            // Appends formatted JSON (2-space indent)
            formattedResult.append(finalJsonArr.getJSONObject(i).toString(2));
            if (i < finalJsonArr.length() - 1) {
                formattedResult.append(",\n");
            }
        }

        singleElementTemplate = formattedResult.toString().trim();

    } catch (JSONException ex1) {
    }
} else {}

But the output is like this.

{"email" : "[email protected]"},
{"email" : "[email protected]"}

Note: I can't use regex as the JSON could also contain nested {}.