Interface OutputFile

All Superinterfaces:
AutoCloseable, Closeable
public interface OutputFile extends Closeable

Abstraction for writing Parquet file data.

This is the write-side counterpart to InputFile. Where reading requires random access, the Parquet container is produced front to back and never seeked backward: the footer carries every offset a reader needs and is emitted last. An OutputFile is therefore a purely sequential sink.

An OutputFile starts in an uncreated state. create() must be called before write(ByteBuffer) or position(); the writer framework (ParquetFileWriter) calls it automatically.

A file is valid only after Closeable.close() returns successfully. A writer abandoned before close() produces no footer and therefore no readable file.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    create()
    Performs resource acquisition (e.g. opening a file channel).
    void
    discard()
    Discards everything written and releases resources without publishing a file at the destination.
    static OutputFile
    of(Path path)
    Creates an uncreated OutputFile for a local file path.
    long
    position()
    Returns the number of bytes written so far, which is the offset at which the next write(ByteBuffer) will begin.
    void
    write(ByteBuffer data)
    Appends the remaining bytes of data to the file.

    Methods inherited from interface Closeable

    close

  • Method Details

    • create

      void create() throws IOException
      Performs resource acquisition (e.g. opening a file channel). Must be called before write(ByteBuffer) or position().
      Throws:
      IOException - if the resource cannot be acquired

    • write

      void write(ByteBuffer data) throws IOException

      Appends the remaining bytes of data to the file.

      The buffer is consumed (its position advances to its limit).

      Parameters:
      data - the bytes to append
      Throws:
      IOException - if the write fails
      IllegalStateException - if create() has not been called

    • position

      long position()
      Returns the number of bytes written so far, which is the offset at which the next write(ByteBuffer) will begin.
      Returns:
      the running byte offset
      Throws:
      IllegalStateException - if create() has not been called

    • discard

      void discard() throws IOException
      Discards everything written and releases resources without publishing a file at the destination. This is the failure counterpart to Closeable.close(): Closeable.close() finalizes (commits) the file, discard() throws it away. The writer calls discard() when it cannot finish a valid file, so a partially written file is never presented as valid. After discard() the destination is left as if nothing was written; calling close() afterwards is a no-op.
      Throws:
      IOException - if resources cannot be released

    • of

      static OutputFile of(Path path)
      Creates an uncreated OutputFile for a local file path.
      Parameters:
      path - the file to write
      Returns:
      a new uncreated OutputFile