Spring Boot JSON Parse Error: Unexpected Character (') - How to Fix

This warning indicates that there was an error while trying to parse a JSON string. The error occurred because a single quote character (') was found where a double-quote character was expected to start a field name in the JSON.

The specific error message is: 'Unexpected character (') (code 39): was expecting double-quote to start field name.'

The issue is likely in the JSON string that was being processed. Check the JSON string for any instances where single quotes are used instead of double quotes for field names or string values. Replace the single quotes with double quotes to fix the issue.