The String.isEmpty() method only checks if a string is null or has zero length. It does not consider strings containing only
whitespace characters as empty, which can lead to unexpected behavior in validation logic.
For example, a string containing only spaces (' ') will return false when checked with isEmpty(), even
though it contains no meaningful content. This can cause issues in:
- User input validation where whitespace-only entries should be rejected
- Data processing where empty fields need to be identified
- Business logic that depends on meaningful string content
The String.isBlank() method provides more comprehensive validation by returning true for null strings, empty strings, and
strings containing only whitespace characters. This makes it the better choice when you need to ensure a string contains actual content.
What is the potential impact?
Using isEmpty() instead of isBlank() can lead to validation bypasses where whitespace-only strings are incorrectly
treated as valid input. This may result in poor data quality, unexpected application behavior, or business logic errors when processing user input or
data fields.
