com.aliyun.odps.volume

Class FileSystem

java.lang.Object

com.aliyun.odps.volume.FileSystem

public abstract class FileSystem
extends Object

VolumeFileSystem have volume partition dir as root, so all paths are relative to partition dir.

Only available at job runtime.

Constructor Summary

Constructors

Constructor and Description
FileSystem()

Method Summary

Modifier and Type	Method and Description
abstract FSDataOutputStream	append(Path f) Append to an existing file (optional operation).
abstract FSDataOutputStream	append(Path f, int bufferSize) Append to an existing file (optional operation).
FSDataOutputStream	create(Path f) Create an FSDataOutputStream at the indicated Path.
abstract FSDataOutputStream	create(Path f, boolean overwrite) Create an FSDataOutputStream at the indicated Path.
abstract FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize) Create an FSDataOutputStream at the indicated Path.
boolean	createNewFile(Path f) Creates the given Path as a brand-new zero-length file.
abstract boolean	delete(Path f) Delete a file.
boolean	delete(Path f, boolean recursive) Non-recursive delete not supported, just for compatible with hadoop.
boolean	exists(Path f) Check if exists.
abstract FileStatus	getFileStatus(Path f) Return a file status object that represents the path.
boolean	isDirectory(Path f) True iff the named path is a directory.
boolean	isFile(Path f) True iff the named path is a regular file.
abstract FileStatus[]	listStatus(Path f) List the statuses of the files/directories in the given path if the path is a directory.
FileStatus[]	listStatus(Path[] files) Filter files/directories in the given list of paths using default path filter.
FileStatus[]	listStatus(Path[] files, PathFilter filter) Filter files/directories in the given list of paths using user-supplied path filter.
FileStatus[]	listStatus(Path f, PathFilter filter) Filter files/directories in the given path using the user-supplied path filter.
abstract boolean	mkdirs(Path f) Make the given file and all non-existent parents into directories.
abstract FSDataInputStream	open(Path f) Opens an FSDataInputStream at the indicated Path.
abstract FSDataInputStream	open(Path f, int bufferSize) Opens an FSDataInputStream at the indicated Path.
abstract boolean	rename(Path src, Path dst) Renames Path src to Path dst.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileSystem

public FileSystem()

Method Detail

open

public abstract FSDataInputStream open(Path f,
                                       int bufferSize)
                                throws IOException

Opens an FSDataInputStream at the indicated Path.

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Throws:

IOException

open

public abstract FSDataInputStream open(Path f)
                                throws IOException

Opens an FSDataInputStream at the indicated Path.

Parameters:

f - the file to open

Throws:

IOException

create

public FSDataOutputStream create(Path f)
                          throws IOException

Create an FSDataOutputStream at the indicated Path. Files are overwritten by default.

Parameters:

f - the file to create

Throws:

IOException

create

public abstract FSDataOutputStream create(Path f,
                                          boolean overwrite)
                                   throws IOException

Create an FSDataOutputStream at the indicated Path.

Parameters:

f - the file to create

overwrite - if a file with this name already exists, then if true, the file will be overwritten, and if false an exception will be thrown.

Throws:

IOException

create

public abstract FSDataOutputStream create(Path f,
                                          boolean overwrite,
                                          int bufferSize)
                                   throws IOException

Create an FSDataOutputStream at the indicated Path.

Parameters:

f - the file name to create

overwrite - if a file with this name already exists, then if true, the file will be overwritten, and if false an error will be thrown.

bufferSize - the size of the buffer to be used.

Throws:

IOException

createNewFile

public boolean createNewFile(Path f)
                      throws IOException

Creates the given Path as a brand-new zero-length file. If create fails, or if it already existed, return false.

Parameters:

f - path to use for create

Throws:

IOException

append

public abstract FSDataOutputStream append(Path f)
                                   throws IOException

Append to an existing file (optional operation).

Parameters:

f - the existing file to be appended.

Throws:

IOException

append

public abstract FSDataOutputStream append(Path f,
                                          int bufferSize)
                                   throws IOException

Append to an existing file (optional operation). Same as append(f, bufferSize, null).

Parameters:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

Throws:

IOException

rename

public abstract boolean rename(Path src,
                               Path dst)
                        throws IOException

Renames Path src to Path dst. Can take place on local fs or remote DFS.

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

delete

public abstract boolean delete(Path f)
                        throws IOException

Delete a file. Always recursive delete.

Parameters:

f - the path to delete.

Returns:

true if delete is successful else false.

Throws:

IOException

delete

public boolean delete(Path f,
                      boolean recursive)
               throws IOException

Non-recursive delete not supported, just for compatible with hadoop.

Throws:

IOException

exists

public boolean exists(Path f)
               throws IOException

Check if exists.

Parameters:

f - source file

Throws:

IOException

isDirectory

public boolean isDirectory(Path f)
                    throws IOException

True iff the named path is a directory. Note: Avoid using this method. Instead reuse the FileStatus returned by getFileStatus() or listStatus() methods.

Parameters:

f - path to check

Throws:

IOException

isFile

public boolean isFile(Path f)
               throws IOException

True iff the named path is a regular file. Note: Avoid using this method. Instead reuse the FileStatus returned by getFileStatus() or listStatus() methods.

Parameters:

f - path to check

Throws:

IOException

listStatus

public abstract FileStatus[] listStatus(Path f)
                                 throws FileNotFoundException,
                                        IOException

List the statuses of the files/directories in the given path if the path is a directory.

Parameters:

f - given path

Returns:

the statuses of the files/directories in the given patch

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException

listStatus

public FileStatus[] listStatus(Path f,
                               PathFilter filter)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given path using the user-supplied path filter.

Parameters:

f - a path name

filter - the user-supplied path filter

Returns:

an array of FileStatus objects for the files under the given path after applying the filter

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException

listStatus

public FileStatus[] listStatus(Path[] files)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given list of paths using default path filter.

Parameters:

files - a list of paths

Returns:

a list of statuses for the files under the given paths after applying the filter default Path filter

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException

listStatus

public FileStatus[] listStatus(Path[] files,
                               PathFilter filter)
                        throws FileNotFoundException,
                               IOException

Filter files/directories in the given list of paths using user-supplied path filter.

Parameters:

files - a list of paths

filter - the user-supplied path filter

Returns:

a list of statuses for the files under the given paths after applying the filter

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException

mkdirs

public abstract boolean mkdirs(Path f)
                        throws IOException

Make the given file and all non-existent parents into directories. Has the semantics of Unix 'mkdir -p'. Existence of the directory hierarchy is not an error.

Parameters:

f - path to create

Throws:

IOException

getFileStatus

public abstract FileStatus getFileStatus(Path f)
                                  throws IOException

Return a file status object that represents the path.

Parameters:

f - The path we want information from

Returns:

a FileStatus object

Throws:

FileNotFoundException - when the path does not exist; IOException see specific implementation

IOException