org.apache.hadoop.fs

Class FSLinkResolver<T>

java.lang.Object

org.apache.hadoop.fs.FSLinkResolver<T>

@InterfaceAudience.Private
@InterfaceStability.Evolving
public abstract class FSLinkResolver<T>
extends Object

Used primarily by FileContext to operate on and resolve symlinks in a path. Operations can potentially span multiple AbstractFileSystems.

See Also:

FileSystemLinkResolver

Constructor Summary

Constructors

Constructor and Description
FSLinkResolver()

Method Summary

Methods

Modifier and Type	Method and Description
abstract T	next(AbstractFileSystem fs, Path p) Generic helper function overridden on instantiation to perform a specific operation on the given file system using the given path which may result in an UnresolvedLinkException.
static Path	qualifySymlinkTarget(URI pathURI, Path pathWithLink, Path target) Return a fully-qualified version of the given symlink target if it has no scheme and authority.
T	resolve(FileContext fc, Path path) Performs the operation specified by the next function, calling it repeatedly until all symlinks in the given path are resolved.

Methods inherited from class java.lang.Object

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

Constructor Detail

FSLinkResolver

public FSLinkResolver()

Method Detail

qualifySymlinkTarget

public static Path qualifySymlinkTarget(URI pathURI,
                        Path pathWithLink,
                        Path target)

Return a fully-qualified version of the given symlink target if it has no scheme and authority. Partially and fully-qualified paths are returned unmodified.

Parameters:

pathURI - URI of the filesystem of pathWithLink

pathWithLink - Path that contains the symlink

target - The symlink's absolute target

Returns:

Fully qualified version of the target.

next

public abstract T next(AbstractFileSystem fs,
     Path p)
                throws IOException,
                       UnresolvedLinkException

Generic helper function overridden on instantiation to perform a specific operation on the given file system using the given path which may result in an UnresolvedLinkException.

Parameters:

fs - AbstractFileSystem to perform the operation on.

p - Path given the file system.

Returns:

Generic type determined by the specific implementation.

Throws:

UnresolvedLinkException - If symbolic link path could not be resolved

IOException - an I/O error occurred

resolve

public T resolve(FileContext fc,
        Path path)
          throws IOException

Performs the operation specified by the next function, calling it repeatedly until all symlinks in the given path are resolved.

Parameters:

fc - FileContext used to access file systems.

path - The path to resolve symlinks on.

Returns:

Generic type determined by the implementation of next.

Throws:

IOException