apache/hadoop · error · NullPointerException

ZstdDecompressCtx is not initialized

Error message

ZstdDecompressCtx is not initialized

What it means

Error "ZstdDecompressCtx is not initialized" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/zstd/ZStandardDecompressor.java:254

    userBufferBytesToConsume = 0;
  }

  @Override
  public void end() {
    if (zstdJniCtx != null) {
      zstdJniCtx.close();
      zstdJniCtx = null;
    }
  }

  @Override
  protected void finalize() {
    end();
  }

  private void checkStream() {
    if (zstdJniCtx == null) {
      throw new NullPointerException("ZstdDecompressCtx is not initialized");
    }
  }

  private int populateUncompressedBuffer(byte[] b, int off, int len, int n) {
    n = Math.min(n, len);
    uncompressedDirectBuf.get(b, off, n);
    return n;
  }

  int inflateDirect(ByteBuffer src, ByteBuffer dst) {
    assert (this instanceof ZStandardDecompressor.ZStandardDirectDecompressor);

    int origDstPos = dst.position();
    boolean done = zstdJniCtx.decompressDirectByteBufferStream(dst, src);
    remaining = src.limit() - src.position();
    // Mirror decompress(): only mark finished when the frame is done AND no
    // more bytes remain (src may contain additional concatenated frames).
    if (done && remaining == 0) {

View on GitHub (pinned to 2add963021)

Solutions

1. Ensure the native zstd library loaded successfully and the decompressor context was initialized; do not use the decompressor after close().

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/zstd/ZStandardDecompressor.java:254 when the library encounters an invalid state.

Common situations: Occurs when the native Zstd decompression context is not initialized. Initialize the decompressor before use and do not call decompress after close.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/efeffde0edbe91ae. Report an issue: GitHub.