Package org.apache.hadoop.fs

Class RawLocalFileSystem

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FileSystem

org.apache.hadoop.fs.RawLocalFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, Configurable, BulkDeleteSource, org.apache.hadoop.fs.PathCapabilities, org.apache.hadoop.security.token.DelegationTokenIssuer

@Public
@Stable
public class RawLocalFileSystem
extends FileSystem

Implement the FileSystem API for the raw local filesystem.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.fs.FileSystem

org.apache.hadoop.fs.FileSystem.DirectoryEntries, org.apache.hadoop.fs.FileSystem.DirListingIterator<T extends FileStatus>, org.apache.hadoop.fs.FileSystem.Statistics

Field Summary

Fields inherited from class org.apache.hadoop.fs.FileSystem

DEFAULT_FS, FS_DEFAULT_NAME_KEY, LOG, SHUTDOWN_HOOK_PRIORITY, statistics, TRASH_PREFIX, USER_HOME_PREFIX

Fields inherited from interface org.apache.hadoop.security.token.DelegationTokenIssuer

TOKEN_LOG

Constructor Summary

Constructors

Constructor	Description
RawLocalFileSystem()

Method Summary

Modifier and Type	Method	Description
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress)	Append to an existing file (optional operation).
void	close()	Close this FileSystem instance.
void	completeLocalOutput(Path fsWorkingFile, Path tmpLocalFile)	Called when we're all done writing to the target.
void	concat(Path trg, Path[] psrcs)	Concat existing files together.
FSDataOutputStream	create(Path f, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress)	Create an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	create(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress)	Create an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress)	Opens an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress)	Opens an FSDataOutputStream at the indicated Path with write-progress reporting.
protected OutputStream	createOutputStream(Path f, boolean append)
protected OutputStream	createOutputStreamWithMode(Path f, boolean append, FsPermission permission)
protected PathHandle	createPathHandle(FileStatus stat, org.apache.hadoop.fs.Options.HandleOpt... opts)	Hook to implement support for PathHandle operations.
void	createSymlink(Path target, Path link, boolean createParent)	See FileContext.createSymlink(Path, Path, boolean).
boolean	delete(Path p, boolean recursive)	Delete the given path to a file or directory.
boolean	exists(Path f)	Check if a path exists.
FileStatus	getFileLinkStatus(Path f)	Return a FileStatus representing the given path.
FileStatus	getFileStatus(Path f)	Return a file status object that represents the path.
Path	getHomeDirectory()	Return the current user's home directory in this FileSystem.
protected Path	getInitialWorkingDirectory()	Note: with the new FileContext class, getWorkingDirectory() will be removed.
Path	getLinkTarget(Path f)	See FileContext.getLinkTarget(Path).
FsStatus	getStatus(Path p)	Returns a status object describing the use and capacity of the filesystem.
URI	getUri()	Returns a URI which identifies this FileSystem.
Path	getWorkingDirectory()	Get the current working directory for the given FileSystem
final boolean	handleEmptyDstDirectoryOnWindows(Path src, File srcFile, Path dst, File dstFile)
boolean	hasPathCapability(Path path, String capability)	The base FileSystem implementation generally has no knowledge of the capabilities of actual implementations.
void	initialize(URI uri, Configuration conf)	Initialize a FileSystem.
FileStatus[]	listStatus(Path f)	List the statuses of the files/directories in the given path if the path is a directory.
boolean	mkdirs(Path f)	Creates the specified directory hierarchy.
boolean	mkdirs(Path f, FsPermission permission)	Make the given file and all non-existent parents into directories.
protected boolean	mkOneDir(File p2f)
protected boolean	mkOneDirWithMode(Path p, File p2f, FsPermission permission)
void	moveFromLocalFile(Path src, Path dst)	The src file is on the local disk.
FSDataInputStream	open(PathHandle fd, int bufferSize)	Open an FSDataInputStream matching the PathHandle instance.
FSDataInputStream	open(Path f, int bufferSize)	Opens an FSDataInputStream at the indicated Path.
File	pathToFile(Path path)	Convert a path to a File.
boolean	rename(Path src, Path dst)	Renames Path src to Path dst.
void	setOwner(Path p, String username, String groupname)	Use the command chown to set owner.
void	setPermission(Path p, FsPermission permission)	Use the command chmod to set permission.
void	setTimes(Path p, long mtime, long atime)	Sets the Path's last modified time and last access time to the given valid times.
void	setWorkingDirectory(Path newDir)	Set the working directory to the given directory.
Path	startLocalOutput(Path fsOutputFile, Path tmpLocalFile)	Returns a local file that the user can write output to.
boolean	supportsSymlinks()	See AbstractFileSystem.supportsSymlinks().
String	toString()
boolean	truncate(Path f, long newLength)	Truncate the file in the indicated path to the indicated size.
static void	useStatIfAvailable()

Methods inherited from class org.apache.hadoop.fs.FileSystem

access, append, append, append, append, appendFile, areSymlinksEnabled, cancelDeleteOnExit, canonicalizeUri, checkPath, clearStatistics, closeAll, closeAllForUGI, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, createBulkDelete, createDataInputStreamBuilder, createDataInputStreamBuilder, createDataOutputStreamBuilder, createFile, createMultipartUploader, createNewFile, createNonRecursive, createSnapshot, createSnapshot, delete, deleteOnExit, deleteSnapshot, enableSymlinks, fixRelativePart, get, get, get, getAclStatus, getAdditionalTokenIssuers, getAllStatistics, getAllStoragePolicies, getBlockSize, getCanonicalServiceName, getCanonicalUri, getChildFileSystems, getContentSummary, getDefaultBlockSize, getDefaultBlockSize, getDefaultPort, getDefaultReplication, getDefaultReplication, getDefaultUri, getDelegationToken, getEnclosingRoot, getFileBlockLocations, getFileBlockLocations, getFileChecksum, getFileChecksum, getFileSystemClass, getFSofPath, getGlobalStorageStatistics, getLength, getLocal, getName, getNamed, getPathHandle, getQuotaUsage, getReplication, getScheme, getServerDefaults, getServerDefaults, getStatistics, getStatistics, getStatus, getStoragePolicy, getStorageStatistics, getTrashRoot, getTrashRoots, getUsed, getUsed, getXAttr, getXAttrs, getXAttrs, globStatus, globStatus, isDirectory, isFile, listCorruptFileBlocks, listFiles, listLocatedStatus, listLocatedStatus, listStatus, listStatus, listStatus, listStatusBatch, listStatusIterator, listXAttrs, makeQualified, mkdirs, modifyAclEntries, moveFromLocalFile, moveToLocalFile, msync, newInstance, newInstance, newInstance, newInstanceLocal, open, open, openFile, openFile, openFileWithOptions, openFileWithOptions, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, removeAcl, removeAclEntries, removeDefaultAcl, removeXAttr, rename, renameSnapshot, resolveLink, resolvePath, satisfyStoragePolicy, setAcl, setDefaultUri, setDefaultUri, setQuota, setQuotaByStorageType, setReplication, setStoragePolicy, setVerifyChecksum, setWriteChecksum, setXAttr, setXAttr, unsetStoragePolicy

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.security.token.DelegationTokenIssuer

addDelegationTokens

Constructor Details

RawLocalFileSystem

public RawLocalFileSystem()

Method Details

useStatIfAvailable

@VisibleForTesting
public static void useStatIfAvailable()

pathToFile

public File pathToFile(Path path)

Convert a path to a File.

Parameters:

path - the path.

Returns:

file.

getUri

public URI getUri()

Description copied from class: FileSystem

Returns a URI which identifies this FileSystem.

Specified by:

getUri in class FileSystem

Returns:

the URI of this filesystem.

initialize

public void initialize(URI uri,
 Configuration conf)
                throws IOException

Description copied from class: FileSystem

Initialize a FileSystem. Called after the new FileSystem instance is constructed, and before it is ready for use. FileSystem implementations overriding this method MUST forward it to their superclass, though the order in which it is done, and whether to alter the configuration before the invocation are options of the subclass.

Overrides:

initialize in class FileSystem

Parameters:

uri - a URI whose authority section names the host, port, etc. for this FileSystem

conf - the configuration

Throws:

IOException - on any failure to initialize this instance.

open

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

Description copied from class: FileSystem

Opens an FSDataInputStream at the indicated Path.

Specified by:

open in class FileSystem

Parameters:

f - the file name to open

bufferSize - the size of the buffer to be used.

Returns:

input stream.

Throws:

IOException - IO failure

open

public FSDataInputStream open(PathHandle fd,
 int bufferSize)
                       throws IOException

Description copied from class: FileSystem

Open an FSDataInputStream matching the PathHandle instance. The implementation may encode metadata in PathHandle to address the resource directly and verify that the resource referenced satisfies constraints specified at its construciton.

Overrides:

open in class FileSystem

Parameters:

fd - PathHandle object returned by the FS authority.

bufferSize - the size of the buffer to use

Returns:

input stream.

Throws:

InvalidPathHandleException - If PathHandle constraints are not satisfied

IOException - IO failure

append

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

Description copied from class: FileSystem

Append to an existing file (optional operation).

Specified by:

append in class FileSystem

Parameters:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

progress - for reporting progress if it is not null.

Returns:

output stream.

Throws:

IOException - IO failure

create

public FSDataOutputStream create(Path f,
 boolean overwrite,
 int bufferSize,
 short replication,
 long blockSize,
 Progressable progress)
                          throws IOException

Description copied from class: FileSystem

Create an FSDataOutputStream at the indicated Path with write-progress reporting.

Overrides:

create in class FileSystem

Parameters:

f - the file name to open

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.

replication - required block replication for the file.

blockSize - the size of the buffer to be used.

progress - to report progress.

Returns:

output stream.

Throws:

IOException - IO failure

createOutputStream

protected OutputStream createOutputStream(Path f,
 boolean append)
                                   throws IOException

Throws:

IOException

createOutputStreamWithMode

protected OutputStream createOutputStreamWithMode(Path f,
 boolean append,
 FsPermission permission)
                                           throws IOException

Throws:

IOException

createNonRecursive

public FSDataOutputStream createNonRecursive(Path f,
 FsPermission permission,
 EnumSet<CreateFlag> flags,
 int bufferSize,
 short replication,
 long blockSize,
 Progressable progress)
                                      throws IOException

Description copied from class: FileSystem

Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.

Overrides:

createNonRecursive in class FileSystem

Parameters:

f - the file name to open

permission - file permission

flags - CreateFlags to use for this stream.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

blockSize - block size

progress - the progress reporter

Returns:

output stream.

Throws:

IOException - IO failure

See Also:

• FileSystem.setPermission(Path, FsPermission)

create

public FSDataOutputStream create(Path f,
 FsPermission permission,
 boolean overwrite,
 int bufferSize,
 short replication,
 long blockSize,
 Progressable progress)
                          throws IOException

Description copied from class: FileSystem

Create an FSDataOutputStream at the indicated Path with write-progress reporting.

Specified by:

create in class FileSystem

Parameters:

f - the file name to open

permission - file permission

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.

replication - required block replication for the file.

blockSize - block size

progress - the progress reporter

Returns:

output stream.

Throws:

IOException - IO failure

See Also:

• FileSystem.setPermission(Path, FsPermission)

createNonRecursive

public FSDataOutputStream createNonRecursive(Path f,
 FsPermission permission,
 boolean overwrite,
 int bufferSize,
 short replication,
 long blockSize,
 Progressable progress)
                                      throws IOException

Description copied from class: FileSystem

Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.

Overrides:

createNonRecursive in class FileSystem

Parameters:

f - the file name to open

permission - file permission

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.

replication - required block replication for the file.

blockSize - block size

progress - the progress reporter

Returns:

output stream.

Throws:

IOException - IO failure

See Also:

• FileSystem.setPermission(Path, FsPermission)

concat

public void concat(Path trg,
 Path[] psrcs)
            throws IOException

Description copied from class: FileSystem

Concat existing files together.

Overrides:

concat in class FileSystem

Parameters:

trg - the path to the target destination.

psrcs - the paths to the sources to use for the concatenation.

Throws:

IOException - IO failure

rename

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

Description copied from class: FileSystem

Renames Path src to Path dst.

Specified by:

rename in class FileSystem

Parameters:

src - path to be renamed

dst - new path after rename

Returns:

true if rename is successful

Throws:

IOException - on failure

handleEmptyDstDirectoryOnWindows

@VisibleForTesting
public final boolean handleEmptyDstDirectoryOnWindows(Path src,
 File srcFile,
 Path dst,
 File dstFile)
                                               throws IOException

Throws:

IOException

truncate

public boolean truncate(Path f,
 long newLength)
                 throws IOException

Description copied from class: FileSystem

Truncate the file in the indicated path to the indicated size.

• Fails if path is a directory.
• Fails if path does not exist.
• Fails if path is not closed.
• Fails if new size is greater than current size.

Overrides:

truncate in class FileSystem

Parameters:

f - The path to the file to be truncated

newLength - The size the file is to be truncated to

Returns:

true if the file has been truncated to the desired newLength and is immediately available to be reused for write operations such as append, or false if a background process of adjusting the length of the last block has been started, and clients should wait for it to complete before proceeding with further file updates.

Throws:

IOException - IO failure

delete

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

Delete the given path to a file or directory.

Specified by:

delete in class FileSystem

Parameters:

p - the path to delete

recursive - to delete sub-directories

Returns:

true if the file or directory and all its contents were deleted

Throws:

IOException - if p is non-empty and recursive is false

listStatus

public FileStatus[] listStatus(Path f)
                        throws IOException

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

Does not guarantee to return the List of files/directories status in a sorted order.

Will not return null. Expect IOException upon access error. (Note: Returned list is not sorted in any given order, due to reliance on Java's File.list() API.)

Specified by:

listStatus in class FileSystem

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

exists

public boolean exists(Path f)
               throws IOException

Description copied from class: FileSystem

Check if a path exists. It is highly discouraged to call this method back to back with other FileSystem.getFileStatus(Path) calls, as this will involve multiple redundant RPC calls in HDFS.

Overrides:

exists in class FileSystem

Parameters:

f - source path

Returns:

true if the path exists

Throws:

IOException - IO failure

mkOneDir

protected boolean mkOneDir(File p2f)
                    throws IOException

Throws:

IOException

mkOneDirWithMode

protected boolean mkOneDirWithMode(Path p,
 File p2f,
 FsPermission permission)
                            throws IOException

Throws:

IOException

mkdirs

public boolean mkdirs(Path f)
               throws IOException

Creates the specified directory hierarchy. Does not treat existence as an error.

Overrides:

mkdirs in class FileSystem

Parameters:

f - path

Returns:

true if the directory was created

Throws:

IOException - IO failure

mkdirs

public boolean mkdirs(Path f,
 FsPermission permission)
               throws IOException

Description copied from class: FileSystem

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

Specified by:

mkdirs in class FileSystem

Parameters:

f - path to create

permission - to apply to f

Returns:

if mkdir success true, not false.

Throws:

IOException - IO failure

getHomeDirectory

public Path getHomeDirectory()

Description copied from class: FileSystem

Return the current user's home directory in this FileSystem. The default implementation returns "/user/$USER/".

Overrides:

getHomeDirectory in class FileSystem

Returns:

the path.

setWorkingDirectory

public void setWorkingDirectory(Path newDir)

Set the working directory to the given directory.

Specified by:

setWorkingDirectory in class FileSystem

Parameters:

newDir - Path of new working directory

getWorkingDirectory

public Path getWorkingDirectory()

Description copied from class: FileSystem

Get the current working directory for the given FileSystem

Specified by:

getWorkingDirectory in class FileSystem

Returns:

the directory pathname

getInitialWorkingDirectory

protected Path getInitialWorkingDirectory()

Description copied from class: FileSystem

Note: with the new FileContext class, getWorkingDirectory() will be removed. The working directory is implemented in FileContext. Some FileSystems like LocalFileSystem have an initial workingDir that we use as the starting workingDir. For other file systems like HDFS there is no built in notion of an initial workingDir.

Overrides:

getInitialWorkingDirectory in class FileSystem

Returns:

if there is built in notion of workingDir then it is returned; else a null is returned.

getStatus

public FsStatus getStatus(Path p)
                   throws IOException

Description copied from class: FileSystem

Returns a status object describing the use and capacity of the filesystem. If the filesystem has multiple partitions, the use and capacity of the partition pointed to by the specified path is reflected.

Overrides:

getStatus in class FileSystem

Parameters:

p - Path for which status should be obtained. null means the default partition.

Returns:

a FsStatus object

Throws:

IOException - see specific implementation

moveFromLocalFile

public void moveFromLocalFile(Path src,
 Path dst)
                       throws IOException

Description copied from class: FileSystem

The src file is on the local disk. Add it to the filesystem at the given dst name, removing the source afterwards.

Overrides:

moveFromLocalFile in class FileSystem

Parameters:

src - local path

dst - path

Throws:

IOException - IO failure

startLocalOutput

public Path startLocalOutput(Path fsOutputFile,
 Path tmpLocalFile)
                      throws IOException

Description copied from class: FileSystem

Returns a local file that the user can write output to. The caller provides both the eventual target name in this FileSystem and the local working file path. If this FileSystem is local, we write directly into the target. If the FileSystem is not local, we write into the tmp local area.

Overrides:

startLocalOutput in class FileSystem

Parameters:

fsOutputFile - path of output file

tmpLocalFile - path of local tmp file

Returns:

the path.

Throws:

IOException - IO failure

completeLocalOutput

public void completeLocalOutput(Path fsWorkingFile,
 Path tmpLocalFile)
                         throws IOException

Description copied from class: FileSystem

Called when we're all done writing to the target. A local FS will do nothing, because we've written to exactly the right place. A remote FS will copy the contents of tmpLocalFile to the correct target at fsOutputFile.

Overrides:

completeLocalOutput in class FileSystem

Parameters:

fsWorkingFile - path of output file

tmpLocalFile - path to local tmp file

Throws:

IOException - IO failure

close

public void close()
           throws IOException

Description copied from class: FileSystem

Close this FileSystem instance. Will release any held locks, delete all files queued for deletion through calls to FileSystem.deleteOnExit(Path), and remove this FS instance from the cache, if cached. After this operation, the outcome of any method call on this FileSystem instance, or any input/output stream created by it is undefined.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FileSystem

Throws:

IOException - IO failure

toString

public String toString()

Overrides:

toString in class Object

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws IOException

Description copied from class: FileSystem

Return a file status object that represents the path.

Specified by:

getFileStatus in class FileSystem

Parameters:

f - The path we want information from

Returns:

a FileStatus object

Throws:

FileNotFoundException - when the path does not exist

IOException - see specific implementation

setOwner

public void setOwner(Path p,
 String username,
 String groupname)
              throws IOException

Use the command chown to set owner.

Overrides:

setOwner in class FileSystem

Parameters:

p - The path

username - If it is null, the original username remains unchanged.

groupname - If it is null, the original groupname remains unchanged.

Throws:

IOException - IO failure

setPermission

public void setPermission(Path p,
 FsPermission permission)
                   throws IOException

Use the command chmod to set permission.

Overrides:

setPermission in class FileSystem

Parameters:

p - The path

permission - permission

Throws:

IOException - IO failure

setTimes

public void setTimes(Path p,
 long mtime,
 long atime)
              throws IOException

Sets the Path's last modified time and last access time to the given valid times.

Overrides:

setTimes in class FileSystem

Parameters:

mtime - the modification time to set (only if no less than zero).

atime - the access time to set (only if no less than zero).

p - The path

Throws:

IOException - if setting the times fails.

createPathHandle

protected PathHandle createPathHandle(FileStatus stat,
 org.apache.hadoop.fs.Options.HandleOpt... opts)

Hook to implement support for PathHandle operations.

Overrides:

createPathHandle in class FileSystem

Parameters:

stat - Referent in the target FileSystem

opts - Constraints that determine the validity of the PathHandle reference.

Returns:

path handle.

supportsSymlinks

public boolean supportsSymlinks()

Description copied from class: FileSystem

See AbstractFileSystem.supportsSymlinks().

Overrides:

supportsSymlinks in class FileSystem

Returns:

if support symlinkls true, not false.

createSymlink

public void createSymlink(Path target,
 Path link,
 boolean createParent)
                   throws IOException

Description copied from class: FileSystem

See FileContext.createSymlink(Path, Path, boolean).

Overrides:

createSymlink in class FileSystem

Parameters:

target - target path.

link - link.

createParent - create parent.

Throws:

AccessControlException - if access is denied.

FileAlreadyExistsException - when the path does not exist.

FileNotFoundException - when the path does not exist.

ParentNotDirectoryException - if the parent path of dest is not a directory.

UnsupportedFileSystemException - if there was no known implementation for the scheme.

IOException - raised on errors performing I/O.

getFileLinkStatus

public FileStatus getFileLinkStatus(Path f)
                             throws IOException

Return a FileStatus representing the given path. If the path refers to a symlink return a FileStatus representing the link rather than the object the link refers to.

Overrides:

getFileLinkStatus in class FileSystem

Parameters:

f - the path.

Returns:

file status

Throws:

AccessControlException - if access is denied.

FileNotFoundException - when the path does not exist.

IOException - raised on errors performing I/O.

UnsupportedFileSystemException - if there was no known implementation for the scheme.

getLinkTarget

public Path getLinkTarget(Path f)
                   throws IOException

Description copied from class: FileSystem

See FileContext.getLinkTarget(Path).

Overrides:

getLinkTarget in class FileSystem

Parameters:

f - the path.

Returns:

the path.

Throws:

IOException - IO failure.

hasPathCapability

public boolean hasPathCapability(Path path,
 String capability)
                          throws IOException

Description copied from class: FileSystem

The base FileSystem implementation generally has no knowledge of the capabilities of actual implementations. Unless it has a way to explicitly determine the capabilities, this method returns false. Probe for a specific capability under the given path. If the function returns true, this instance is explicitly declaring that the capability is available. If the function returns false, it can mean one of:

• The capability is not known.
• The capability is known but it is not supported.
• The capability is known but the filesystem does not know if it is supported under the supplied path.

The core guarantee which a caller can rely on is: if the predicate returns true, then the specific operation/behavior can be expected to be supported. However a specific call may be rejected for permission reasons, the actual file/directory not being present, or some other failure during the attempted execution of the operation.

Implementors: PathCapabilitiesSupport can be used to help implement this method.

Specified by:

hasPathCapability in interface org.apache.hadoop.fs.PathCapabilities

Overrides:

hasPathCapability in class FileSystem

Parameters:

path - path to query the capability of.

capability - non-null, non-empty string to query the path for support.

Returns:

true if the capability is supported under that part of the FS.

Throws:

IOException - this should not be raised, except on problems resolving paths or relaying the call.