apache/druid · error · NullPointerException

Input is null

Error message

Input is null

What it means

Numbers.parseLong converts a String or Number object to a primitive long. A null input is neither type, so the method throws NullPointerException with the message "Input is null" rather than returning a default. This makes silent null coercion impossible for callers who expect a value.

Solutions

1. Ensure the input value is set before parsing (supply the field in the spec/config)
2. Check for null first and substitute a default: val == null ? 0L : Numbers.parseLong(val)
3. Use a nullable-aware accessor like MapUtils.getLong with a default for map inputs
4. Inspect why the upstream produced null (wrong key, skipped field, earlier filter)

Example fix

// before
long ts = Numbers.parseLong(queryContext.get("timeout"));
// after
Object v = queryContext.get("timeout");
long ts = v == null ? 30000L : Numbers.parseLong(v);

if (val == null) {
  throw new IllegalArgumentException("Numeric field is required but was null");
}
long n = Numbers.parseLong(val);

static Long safeParseLong(Object val) {
  return val == null ? null : (val instanceof String || val instanceof Number ? Numbers.parseLong(val) : null);
}

try {
  return Numbers.parseLong(val);
} catch (NullPointerException e) {
  log.warn("parseLong got null; using default");
  return 0L;
}

When it happens

Trigger: Calling Numbers.parseLong(null) directly, or passing a map/JSON field that is absent or explicitly null.

Common situations: Optional JSON fields missing from ingestion specs or query parameters; a config map entry removed in a newer spec version; passing the result of Map.get() without a null check.

Related errors

• Cannot have a null result!
• Could not convert value
• Could not convert value
• Could not convert value
• Could not convert value

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/5b55f497f52180fb. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/java/util/common/Numbers.java:47

{
  /**
   * Parse the given object as a {@code long}. The input object can be a {@link String} or one of the implementations of
   * {@link Number}. You may want to use {@code GuavaUtils.tryParseLong()} instead if the input is a nullable string and
   * you want to avoid any exceptions.
   *
   * @throws NumberFormatException if the input is an unparseable string.
   * @throws NullPointerException if the input is null.
   * @throws ISE if the input is not a string or a number.
   */
  public static long parseLong(Object val)
  {
    if (val instanceof String) {
      return Long.parseLong((String) val);
    } else if (val instanceof Number) {
      return ((Number) val).longValue();
    } else {
      if (val == null) {
        throw new NullPointerException("Input is null");
      } else {
        throw new ISE("Unknown type [%s]", val.getClass());
      }
    }
  }

  /**
   * Parse the given object as a {@code int}. The input object can be a {@link String} or one of the implementations of
   * {@link Number}.
   *
   * @throws NumberFormatException if the input is an unparseable string.
   * @throws NullPointerException if the input is null.
   * @throws ISE if the input is not a string or a number.
   */
  public static int parseInt(Object val)
  {
    if (val instanceof String) {
      return Integer.parseInt((String) val);

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