# Package org.apache.hadoop.fs

An abstract file system API.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  BatchedRemoteIterator.BatchedEntries<E> |
  BlockStoragePolicySpi | A storage policy specifies the placement of block replicas on specific storage types.
  ByteBufferReadable | Implementers of this interface provide a read API that writes to a ByteBuffer, not a byte[].
  CanSetDropBehind |
  CanSetReadahead |
  CanUnbuffer | FSDataInputStreams implement this interface to indicate that they can clear their buffers on request.
  DelegationTokenRenewer.Renewable | The renewable interface used by the renewer.
  FsConstants | FileSystem related constants.
  FSProtos.FileStatusProtoOrBuilder |
  FSProtos.FsPermissionProtoOrBuilder |
  FSProtos.LocalFileSystemPathHandleProtoOrBuilder |
  GetSpaceUsed |
  GlobalStorageStatistics.StorageStatisticsProvider | A callback API for creating new StorageStatistics instances.
  PartHandle | Opaque, serializable reference to a part id for multipart uploads.
  PathCapabilities | The Path counterpoint to `StreamCapabilities`; a query to see if, a FileSystem/FileContext instance has a specific capability under the given path.
  PathFilter |
  PathHandle | Opaque, serializable reference to an entity in the FileSystem.
  PositionedReadable | Stream that permits positional reading.
  RemoteIterator<E> | An iterator over a collection whose elements need to be fetched remotely
  Seekable | Stream that permits seeking.
  StorageStatistics.CommonStatisticNames | These are common statistic names.
  StreamCapabilities | Interface to query streams for supported capabilities.
  Syncable | This interface for flush/sync operation.
  UploadHandle | Opaque, serializable reference to an uploadId for multipart uploads.

- Class Summary
  Class | Description
  --- | ---
  AbstractFileSystem | This class provides an interface for implementors of a Hadoop file system (analogous to the VFS of Unix).
  AvroFSInput | Adapts an `FSDataInputStream` to Avro's SeekableInput interface.
  BatchedRemoteIterator<K,E> | A RemoteIterator that fetches elements in batches.
  BatchedRemoteIterator.BatchedListEntries<E> |
  BlockLocation | Represents the network location of a block, information about the hosts that contain block replicas, and other block metadata (E.g.
  ChecksumFileSystem | Abstract Checksumed FileSystem.
  CommonConfigurationKeysPublic | This class contains constants for configuration keys used in the common code.
  CommonPathCapabilities | Common path capabilities.
  ContentSummary | Store the summary of a content (a directory or a file).
  ContentSummary.Builder | We don't use generics.
  DelegationTokenRenewer.RenewAction<T extends FileSystem & DelegationTokenRenewer.Renewable> | An action that will renew and replace the file system's delegation tokens automatically.
  DUHelper |
  FileChecksum | An abstract class representing file checksums for files.
  FileContext | The FileContext class provides an interface for users of the Hadoop file system.
  FileStatus | Interface that represents the client side information for a file.
  FileSystem | An abstract base class for a fairly generic filesystem.
  FileSystem.Statistics | Tracks statistics about how many reads, writes, and so forth have been done in a FileSystem.
  FileSystem.Statistics.StatisticsData | Statistics data.
  FileSystemMultipartUploader.Factory | Factory for creating MultipartUploaderFactory objects for file:// filesystems.
  FileUtil | A collection of file-processing util methods
  FileUtil.HardLink | Deprecated Use `HardLink`
  FilterFileSystem | A `FilterFileSystem` contains some other file system, which it uses as its basic file system, possibly transforming the data along the way or providing additional functionality.
  FSDataInputStream | Utility that wraps a `FSInputStream` in a `DataInputStream` and buffers input through a `BufferedInputStream`.
  FSDataOutputStream | Utility that wraps a `OutputStream` in a `DataOutputStream`.
  FSDataOutputStreamBuilder<S extends FSDataOutputStream,B extends FSDataOutputStreamBuilder<S,B>> | Builder for `FSDataOutputStream` and its subclasses.
  FSExceptionMessages | Standard strings to use in exception messages in filesystems HDFS is used as the reference source of the strings
  FSInputStream | FSInputStream is a generic old InputStream with a little bit of RAF-style seek ability.
  FSProtos |
  FSProtos.FileStatusProto | Protobuf type `hadoop.fs.FileStatusProto`
  FSProtos.FileStatusProto.Builder | Protobuf type `hadoop.fs.FileStatusProto`
  FSProtos.FsPermissionProto | Protobuf type `hadoop.fs.FsPermissionProto`
  FSProtos.FsPermissionProto.Builder | Protobuf type `hadoop.fs.FsPermissionProto`
  FSProtos.LocalFileSystemPathHandleProto | Protobuf type `hadoop.fs.LocalFileSystemPathHandleProto`
  FSProtos.LocalFileSystemPathHandleProto.Builder | Protobuf type `hadoop.fs.LocalFileSystemPathHandleProto`
  FsServerDefaults | Provides server default configuration values to clients.
  FsShellPermissions.Chgrp | Used to change group of files
  FsShellPermissions.Chmod | The pattern is almost as flexible as mode allowed by chmod shell command.
  FsShellPermissions.Chown | Used to change owner and/or group of files
  FsStatus | This class is used to represent the capacity, free and used space on a `FileSystem`.
  GetSpaceUsed.Builder | The builder class
  GlobFilter | A filter for POSIX glob pattern with brace expansions.
  HardLink | Class for creating hardlinks.
  HardLink.LinkStats | HardLink statistics counters and methods.
  HarFileSystem | This is an implementation of the Hadoop Archive Filesystem.
  HarFs |
  LocalFileSystem | Implement the FileSystem API for the checksumed local filesystem.
  LocalFileSystemPathHandle | Opaque handle to an entity in a FileSystem.
  LocatedFileStatus | This class defines a FileStatus that includes a file's block locations.
  MD5MD5CRC32CastagnoliFileChecksum | For CRC32 with the Castagnoli polynomial
  MD5MD5CRC32GzipFileChecksum | For CRC32 with the Gzip polynomial
  Options | This class contains options related to file system operations.
  Options.ChecksumOpt | This is used in FileSystem and FileContext to specify checksum options.
  Options.CreateOpts | Class to support the varargs for create() options.
  Options.CreateOpts.BlockSize |
  Options.CreateOpts.BufferSize |
  Options.CreateOpts.BytesPerChecksum | This is not needed if ChecksumParam is specified.
  Options.CreateOpts.ChecksumParam |
  Options.CreateOpts.CreateParent |
  Options.CreateOpts.Perms |
  Options.CreateOpts.Progress |
  Options.CreateOpts.ReplicationFactor |
  Options.HandleOpt | Options for creating `PathHandle` references.
  Options.HandleOpt.Data | Option storing standard constraints on data.
  Options.HandleOpt.Location | Option storing standard constraints on location.
  Path | Names a file or directory in a `FileSystem`.
  QuotaUsage | Store the quota usage of a directory.
  QuotaUsage.Builder | Builder class for QuotaUsage.
  RawLocalFileSystem | Implement the FileSystem API for the raw local filesystem.
  StorageStatistics | StorageStatistics contains statistics data for a FileSystem or FileContext instance.
  StorageStatistics.LongStatistic | A 64-bit storage statistic.
  StreamCapabilitiesPolicy | Static methods to implement policies for `StreamCapabilities`.
  Trash | Provides a trash facility which supports pluggable Trash policies.
  TrashPolicy | This interface is used for implementing different Trash policies.

- Enum Summary
  Enum | Description
  --- | ---
  CreateFlag | CreateFlag specifies the file create semantic.
  FileStatus.AttrFlags | Flags for entity attributes.
  FSProtos.FileStatusProto.FileType | Protobuf enum `hadoop.fs.FileStatusProto.FileType`
  FSProtos.FileStatusProto.Flags | Protobuf enum `hadoop.fs.FileStatusProto.Flags`
  GlobalStorageStatistics | Stores global storage statistics objects.
  Options.ChecksumCombineMode | Enum for indicating what mode to use when combining chunk and block checksums to define an aggregate FileChecksum.
  Options.Rename | Enum to support the varargs for rename() options
  ReadOption | Options that can be used when reading from a FileSystem.
  StorageType | Defines the types of supported storage media.
  StreamCapabilities.StreamCapability | Deprecated
  XAttrCodec | The value of `XAttr` is byte[], this class is to covert byte[] to some kind of string representation or convert back.
  XAttrSetFlag |

- Exception Summary
  Exception | Description
  --- | ---
  ChecksumException | Thrown for checksum errors.
  FileAlreadyExistsException | Used when target file already exists for any operation and is not configured to be overwritten.
  InvalidPathException | Path string is invalid either because it has invalid characters or due to other file system specific reasons.
  InvalidPathHandleException | Thrown when the constraints enoded in a `PathHandle` do not hold.
  InvalidRequestException | Thrown when the user makes a malformed request, for example missing required parameters or parameters that are not valid.
  ParentNotDirectoryException | Indicates that the parent of specified Path is not a directory as expected.
  PathAccessDeniedException | EACCES
  PathExistsException | Exception corresponding to File Exists - EEXISTS
  PathIOException | Exceptions based on standard posix/linux style exceptions for path related errors.
  PathIsDirectoryException | EISDIR
  PathIsNotDirectoryException | ENOTDIR
  PathIsNotEmptyDirectoryException | Generated by rm commands
  PathNotFoundException | Exception corresponding to path not found: ENOENT/ENOFILE
  PathOperationException | ENOTSUP
  PathPermissionException | Exception corresponding to Operation Not Permitted - EPERM
  UnsupportedFileSystemException | File system for a given file system name/scheme is not supported
  UnsupportedMultipartUploaderException | MultipartUploader for a given file system name/scheme is not supported.
  ZeroCopyUnavailableException |

- Error Summary
  Error | Description
  --- | ---
  FSError | Thrown for unexpected filesystem errors, presumed to reflect disk errors in the native filesystem.

## Package org.apache.hadoop.fs Description

An abstract file system API.

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