apache/hadoop · error · IllegalArgumentException

ArrayList<Key> may not be null

Error message

ArrayList<Key> may not be null

What it means

Error "ArrayList<Key> may not be null" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/bloom/Filter.java:160

   * <b>Invariant</b>: The result is assigned to <i>this</i> filter.
   * @param filter The filter to XOR with.
   */
  public abstract void xor(Filter filter);

  /**
   * Performs a logical NOT on <i>this</i> filter.
   * <p>
   * The result is assigned to <i>this</i> filter.
   */
  public abstract void not();

  /**
   * Adds a list of keys to <i>this</i> filter.
   * @param keys The list of keys.
   */
  public void add(List<Key> keys){
    if(keys == null) {
      throw new IllegalArgumentException("ArrayList<Key> may not be null");
    }

    for(Key key: keys) {
      add(key);
    }
  }//end add()

  /**
   * Adds a collection of keys to <i>this</i> filter.
   * @param keys The collection of keys.
   */
  public void add(Collection<Key> keys){
    if(keys == null) {
      throw new IllegalArgumentException("Collection<Key> may not be null");
    }
    for(Key key: keys) {
      add(key);
    }

View on GitHub (pinned to 2add963021)

Solutions

1. The ArrayList<Key> argument is null. Pass a non-null list of keys (empty list is acceptable if the intent is a no-op).

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/bloom/Filter.java:160 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/b2b7ace2b6fee48a. Report an issue: GitHub.