pentaho/pentaho-kettle · error · IllegalArgumentException

S3FileOutput.Error.InvalidRegex

Error message

S3FileOutput.Error.InvalidRegex

What it means

S3FileOutputHelper.fileMatchesFilter compiles the user-supplied filename filter string as a Java regex and rethrows PatternSyntaxException as IllegalArgumentException with the localized message 'S3FileOutput.Error.InvalidRegex' plus the regex engine's description. It exists to surface a bad user-entered filter pattern with a clear message instead of a raw regex stack trace.

Solutions

1. Read e.getDescription() in the message and fix the regex at that position (balance parentheses/brackets, escape special chars).
2. Escape literal characters (e.g. use \. for a dot) or use Pattern.quote() around literal text.
3. If users need glob semantics, translate globs to regex (.* for *, . for ?) before compiling.
4. Validate the pattern with Pattern.compile() in the dialog before running the transformation.

Example fix

// before
Matcher matcher = Pattern.compile( filter ).matcher( file );
// after: accept simple glob input
String regex = filter.replace( ".", "\\." ).replace( "*", ".*" ).replace( "?", "." );
Matcher matcher = Pattern.compile( regex ).matcher( file );

// validate user filter before use
try {
  java.util.regex.Pattern.compile( filter );
} catch ( java.util.regex.PatternSyntaxException pse ) {
  throw new IllegalArgumentException( "Invalid filter regex at pos " + pse.getIndex() + ": " + pse.getDescription() );
}

When it happens

Trigger: showFilesAction -> fileMatchesFilter with a filter string that is not a valid Java regular expression, e.g. unbalanced '(' or '[', trailing backslash, or a dangling quantifier like '*csv'.

Common situations: User types a Windows-style glob with special characters in the S3 File Output filter field; copy-pasted globs with unmatched braces or brackets; filenames containing special regex characters treated as patterns.

Related errors

• RegexEval.Exception.ErrorCaptureGroupFieldsMismatch
• RegexEval.Exception.ErrorMatcherMissing
• RegexEval.Exception.ErrorResultFieldMissing
• A connection of type PALO is expected
• A connection of type PALO is expected

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/08025933dde20b7e. Report an issue: GitHub.

Appendix: source

Thrown at plugins/s3-vfs/core/src/main/java/org/pentaho/amazon/s3/S3FileOutputHelper.java:214

      if ( fileMatchesFilter( file, filter, isRegex ) ) {
        filteredFiles.add( file );
      }
    }
    response.put( FILES_KEY, filteredFiles );
    return response;
  }

  // Checks if file path matches filter criteria (regex or case-insensitive substring)
  private boolean fileMatchesFilter( String file, String filter, String isRegex ) {
    if ( Boolean.parseBoolean( isRegex ) ) {
      if ( S3Util.isEmpty( filter ) ) {
        return true;
      }
      try {
        Matcher matcher = Pattern.compile( filter ).matcher( file );
        return matcher.matches();
      } catch ( PatternSyntaxException e ) {
        throw new IllegalArgumentException(
            BaseMessages.getString(
                PKG,
                "S3FileOutput.Error.InvalidRegex"
            ) + ": " + e.getDescription(),
            e
        );
      }
    } else {
      return S3Util.isEmpty( filter ) || StringUtils.containsIgnoreCase( file, filter );
    }
  }

  @SuppressWarnings( "unchecked" )
  public JSONObject listS3BucketsAction( TransMeta transMeta, Map<String, String> queryParams ) {
    JSONObject response = new JSONObject();
    JSONArray buckets = new JSONArray();
    try {
      S3Details s3Details = createS3DetailsFromParams( transMeta, queryParams );

View on GitHub (pinned to f3058517a1)