org.apache.lucene.store

## Class NIOFSDirectory

- java.lang.Object
- - org.apache.lucene.store.Directory
  - - org.apache.lucene.store.BaseDirectory
    - - org.apache.lucene.store.FSDirectory
      - - org.apache.lucene.store.NIOFSDirectory

- All Implemented Interfaces:
    Closeable, AutoCloseable

      public class NIOFSDirectory
      extends FSDirectory

  An `FSDirectory` implementation that uses java.nio's FileChannel's positional read, which allows multiple threads to read from the same file without synchronizing.

  This class only uses FileChannel when reading; writing is achieved with `FSDirectory.FSIndexOutput`.

  NOTE: NIOFSDirectory is not recommended on Windows because of a bug in how FileChannel.read is implemented in Sun's JRE. Inside of the implementation the position is apparently synchronized. See here for details.

  NOTE: Accessing this class either directly or indirectly from a thread while it's interrupted can close the underlying file descriptor immediately if at the same time the thread is blocked on IO. The file descriptor will remain closed and subsequent access to `NIOFSDirectory` will throw a `ClosedChannelException`. If your application uses either `Thread.interrupt()` or `Future.cancel(boolean)` you should use the legacy `RAFDirectory` from the Lucene `misc` module in favor of `NIOFSDirectory`.

- - ### Field Summary

    - ### Fields inherited from class org.apache.lucene.store.FSDirectory

      `directory`

    - ### Fields inherited from class org.apache.lucene.store.BaseDirectory

      `isOpen, lockFactory`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `NIOFSDirectory(Path path)` Create a new NIOFSDirectory for the named location and `FSLockFactory.getDefault()`.
    `NIOFSDirectory(Path path, LockFactory lockFactory)` Create a new NIOFSDirectory for the named location.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `IndexInput` | `openInput(String name, IOContext context)` Returns a stream reading an existing file.

    - ### Methods inherited from class org.apache.lucene.store.FSDirectory

      `close, createOutput, createTempOutput, deleteFile, deletePendingFiles, ensureCanRead, fileLength, fsync, getDirectory, getPendingDeletions, listAll, listAll, open, open, rename, sync, syncMetaData, toString`

    - ### Methods inherited from class org.apache.lucene.store.BaseDirectory

      `ensureOpen, obtainLock`

    - ### Methods inherited from class org.apache.lucene.store.Directory

      `copyFrom, openChecksumInput`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### NIOFSDirectory

          public NIOFSDirectory(Path path,
                                LockFactory lockFactory)
                         throws IOException

      Create a new NIOFSDirectory for the named location. The directory is created at the named location if it does not yet exist.
      Parameters:
        `path` - the path of the directory
        `lockFactory` - the lock factory to use
      Throws:
        `IOException` - if there is a low-level I/O error

    - #### NIOFSDirectory

          public NIOFSDirectory(Path path)
                         throws IOException

      Create a new NIOFSDirectory for the named location and `FSLockFactory.getDefault()`. The directory is created at the named location if it does not yet exist.
      Parameters:
        `path` - the path of the directory
      Throws:
        `IOException` - if there is a low-level I/O error

  - ### Method Detail

    - #### openInput

          public IndexInput openInput(String name,
                                      IOContext context)
                               throws IOException

      Description copied from class: `Directory`
      Returns a stream reading an existing file.

      Throws `FileNotFoundException` or `NoSuchFileException` if the file does not exist.

      Specified by:
        `openInput` in class `Directory`
      Throws:
        `IOException`

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