stanfordnlp/CoreNLP · error · IllegalArgumentException

Constructor argument not valid list of number ranges

Error message

Constructor argument not valid list of number ranges: <ranges>

What it means

The constructor wraps its whole range-parsing loop in a catch-all; any Exception while parsing (NumberFormatException from a non-integer token, ArrayIndexOutOfBounds from an empty token) is rethrown as this IllegalArgumentException with the original ranges string and cause attached.

Solutions

  1. Inspect the cause (getCause()) to find the offending token and fix the ranges string to only contain integers and hyphens
  2. Pre-validate with a regex \\d+(-\\d+)?(,\\s*\\d+(-\\d+)?)* and reject bad input with your own message
  3. Trim/split defensively: strip spaces, drop empty tokens before constructing the filter

Example fix

// before
new NumberRangesFileFilter("1, 2-5, ,8", false); // empty token -> NumberFormatException
// after
String ranges = "1, 2-5, ,8";
if (!ranges.matches("\\d+(-\\d+)?(,\\s*\\d+(-\\d+)?)*")) {
  throw new IllegalArgumentException("Bad ranges: " + ranges);
}
new NumberRangesFileFilter(ranges, false);
Defensive patterns

Strategy: try-catch

Validate before calling

if (!ranges.matches("\\d+(-\\d+)?(,\\s*\\d+(-\\d+)?)*")) throw new IllegalArgumentException("Bad ranges: " + ranges);

Try / catch

try { f = new NumberRangesFileFilter(ranges, recurse); } catch (IllegalArgumentException e) { log.severe("Bad ranges '" + ranges + "': " + e.getCause()); throw e; }

Prevention

When it happens

Trigger: new NumberRangesFileFilter("1,a-5,,20", false) — any token that fails Integer.parseInt or is empty after trimming.

Common situations: Config/property values with typos or whitespace artifacts, empty entries from trailing commas, format mistakes like "1 to 5" instead of "1-5".

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/94d8535305e16638. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/io/NumberRangesFileFilter.java:75

      String[] ra = ranges.split(",");
      for (String range : ra) {
        String[] one = range.split("-");
        if (one.length > 2) {
          throw new IllegalArgumentException("Constructor argument not valid list of number ranges (too many hyphens): ");
        } else {
          int low = Integer.parseInt(one[0].trim());
          int high;
          if (one.length == 2) {
            high = Integer.parseInt(one[1].trim());
          } else {
            high = low;
          }
          Pair<Integer, Integer> p = new Pair<>(Integer.valueOf(low), Integer.valueOf(high));
          this.ranges.add(p);
        }
      }
    } catch (Exception e) {
      throw new IllegalArgumentException("Constructor argument not valid list of number ranges: " + ranges, e);
    }
  }


  /**
   * Checks whether a file satisfies the number range selection filter.
   * The test is evaluated based on the rightmost natural number found in
   * the filename string (proper, not including directories in a path).
   *
   * @param file The file
   * @return true If the file is within the ranges filtered for
   */
  public boolean accept(File file) {
    if (file.isDirectory()) {
      return recursively;
    } else {
      String filename = file.getName();
      return accept(filename);

View on GitHub (pinned to 1b7edd19c4)