how to match exactly one word among the others in REGEX 'or'(|) condition

I am aware that there are similar questions to this but none of them seem to match my requirement. I am new to regex and still learning. I appreciate Any help with following problem.
I have following input json data. PS: I have simplified the actual data for better understanding of my problem.
1.

{
  "name": "abc",
  "response": {
    "postback": "UNIQUE-a651-95e4834b63cc",
    "text": "testing"
  },
  "remarks": "get keyword"
}

{
  "name": "abc",
  "response": {
    "postback": "a651-95e4834b63cc",
    "text": "testing"
  },
  "remarks": "get keyword"
}

Regex

(UNIQUE)|(\"(response|someothedata|otherdata|somedata)\")

I want to get which of these keywords is matched. here it gets trickier if 'UNIQUE' field is present it should stop right there and not match any further.
I am using following java code

pattern = Pattern.compile("(UNIQUE)|(\"(response|someothedata|otherdata|somedata)\")")  
Matcher matcher = pattern.matcher(message);  
if(matcher.find()){
  match = matcher.group();
}  

for both input json, matcher.group() returns 'response'

I want to achieve following :

for 1. group() to return 'UNIQUE'
for 2. to return 'response' i.e, only if 'UNIQUE' not present

Note: once I get the matched word(match) there are few actions to be done based on that, so that can't be compromised

can anyone please help me how I can somehow prioritize 'UNIQUE' keyword?

You can use

Pattern pattern = Pattern.compile(".*(UNIQUE|\"(?:response|someothedata|otherdata|somedata)\")");
Matcher matcher = pattern.matcher(message);  
if(matcher.find()){
  match = matcher.group(1).replaceAll("^\"|\"$", "");
}  

See the regex demo. Details:

• .* - any zero or more chars other than line break chars, as many as possible (this moves the regex index to the end of string/line)
• (UNIQUE|\"(?:response|someothedata|otherdata|somedata)\") - Group 1: UNIQUE or ", followed with either response, someothedata, otherdata
  or somedata and then "

You are matching a single occurrence of a pattern, and that means it does not matter for you whether the match is first or last. That is why adding .* and grouping UNIQUE and "(?:response|someothedata|otherdata|somedata)" in one capturing group will work. The only "problem" is that the response, etc. words will come with double quotes on both ends, so you can safely remove them with .replaceAll("^\"|\"$", "").