apache/hadoop · error · NullPointerException

Key can not be null

Error message

Key can not be null

What it means

Error "Key can not be null" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/bloom/DynamicBloomFilter.java:139

   * @param hashType type of the hashing function (see
   * {@link org.apache.hadoop.util.hash.Hash}).
   * @param nr The threshold for the maximum number of keys to record in a
   * dynamic Bloom filter row.
   */
  public DynamicBloomFilter(int vectorSize, int nbHash, int hashType, int nr) {
    super(vectorSize, nbHash, hashType);

    this.nr = nr;
    this.currentNbRecord = 0;

    matrix = new BloomFilter[1];
    matrix[0] = new BloomFilter(this.vectorSize, this.nbHash, this.hashType);
  }

  @Override
  public void add(Key key) {
    if (key == null) {
      throw new NullPointerException("Key can not be null");
    }

    BloomFilter bf = getActiveStandardBF();

    if (bf == null) {
      addRow();
      bf = matrix[matrix.length - 1];
      currentNbRecord = 0;
    }

    bf.add(key);

    currentNbRecord++;
  }

  @Override
  public void and(Filter filter) {
    if (filter == null

View on GitHub (pinned to 2add963021)

Solutions

1. Pass a non-null Key to the DynamicBloomFilter operation. Guard the call site against null keys.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/bloom/DynamicBloomFilter.java:139 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/b41076c77dca670c. Report an issue: GitHub.