apache/hadoop · error · InvalidObjectException

No Path in deserialized FileStatus

Error message

No Path in deserialized FileStatus

What it means

FileStatus implements ObjectInputValidation: after Java-native deserialization, validateObject() runs and throws InvalidObjectException when the path field is null. A FileStatus without a path is unusable, so the guard marks the deserialized bytes as incompatible (different class shape) or the object as never properly initialized.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileStatus.java:542

  /**
   * Write instance encoded as protobuf to stream.
   * @param out Output stream
   * @see PBHelper#convert(FileStatus)
   * @deprecated Use the {@link PBHelper} and protobuf serialization directly.
   */
  @Override
  @Deprecated
  public void write(DataOutput out) throws IOException {
    FileStatusProto proto = PBHelper.convert(this);
    int size = proto.getSerializedSize();
    out.writeInt(size);
    out.write(proto.toByteArray());
  }

  @Override
  public void validateObject() throws InvalidObjectException {
    if (null == path) {
      throw new InvalidObjectException("No Path in deserialized FileStatus");
    }
    if (null == isdir) {
      throw new InvalidObjectException("No type in deserialized FileStatus");
    }
  }



}

View on GitHub (pinned to 2add963021)

Solutions

1. Stop Java-serializing FileStatus: send path.toString() and re-stat on the receiver via fs.getFileStatus(new Path(s))
2. Align hadoop-common versions on producer and consumer so the serialized class shape matches
3. If binary transfer is required, use the Writable format (write/readFields) or FileStatusProto instead of native serialization

Example fix

// before
objectOut.writeObject(fileStatus);
FileStatus back = (FileStatus) objectIn.readObject(); // InvalidObjectException

// after: ship the path, re-stat remotely
objectOut.writeUTF(fileStatus.getPath().toString());
// receiver:
FileStatus back = fileSystem.getFileStatus(new Path(objectIn.readUTF()));

try {
  FileStatus st = (FileStatus) objectIn.readObject();
} catch (InvalidObjectException e) {
  // incompatible serialized shape - recover by re-statting a known path
  FileStatus st = fileSystem.getFileStatus(knownPath);
}

When it happens

Trigger: ObjectInputStream.readObject() on FileStatus bytes whose serialized form lacks the path field (producer/consumer Hadoop version mismatch), or round-tripping a FileStatus built with the no-arg constructor and never populated via set()/readFields().

Common situations: Frameworks that Java-serialize objects containing FileStatus across JVMs (Spark RDD caching/shipping, session replication) with different hadoop-common versions on the two sides.

Related errors

• No type in deserialized FileStatus
• %s not found: %s
• Can't read FileStatusProto with negative size of ${size}
• Path must be absolute: " + path
• Append is not supported by BaiduBosFileSystem

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/dafb255f31fd1393. Report an issue: GitHub.