Regex - I need to replace all digits but specific 3 digits numbers

Question

I want to replace all digits on a log with "X", But i want to keep the HTTP status codes for info.

I've been trying different approaches. None of them worked.

str.replaceAll("(?!5\d\d|4\d\d)\d{3}", "X") //Didn't worked

// Error trying to POST to /shipments/X5X5X/select?caller.id=XX592: 500 INTERNAL_SERVER_ERROR

I need it to be:

From:

Error trying to POST to /shipments/28056415973/select?caller.id=116089592: 500 INTERNAL_SERVER_ERROR

To:

Error trying to POST to /shipments/XXXX/select?caller.id=XXXX: 500 INTERNAL_SERVER_ERROR

Answer 1

If the numbers you want to select are never followed by a space and an uppercase char AZ you could use a negative lookahead:

\b[0-9]+\b(?! [A-Z])

Explanation

• \\b[0-9]+\\b Match 1+ digits between word boundaries
• (?! Negative lookahead, assert what is on the right is not
  • [AZ] Match a space and uppercase char AZ
• ) Close lookahead

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