Package org.apache.hadoop.fs.impl

Class FsLinkResolution<T>

java.lang.Object

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

org.apache.hadoop.fs.impl.FsLinkResolution<T>

Type Parameters:

T - type of the returned value.

@Private
@Evolving
public class FsLinkResolution<T>
extends FSLinkResolver<T>

Class to allow Lambda expressions to be used in FileContext link resolution.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	FsLinkResolution.FsLinkResolutionFunction<T>	The signature of the function to invoke.

Constructor Summary

Constructors

Constructor	Description
FsLinkResolution(FsLinkResolution.FsLinkResolutionFunction<T> fn)	Construct an instance with the given function.

Method Summary

Modifier and Type	Method	Description
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 <T> T	resolve(FileContext fileContext, Path path, FsLinkResolution.FsLinkResolutionFunction<T> fn)	Apply the given function to the resolved path under the the supplied FileContext.

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

qualifySymlinkTarget, resolve

Methods inherited from class java.lang.Object

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

Constructor Detail

FsLinkResolution

public FsLinkResolution(FsLinkResolution.FsLinkResolutionFunction<T> fn)

Construct an instance with the given function.

Parameters:

fn - function to invoke.

Method Detail

next

public T next(AbstractFileSystem fs,
              Path p)
       throws UnresolvedLinkException,
              java.io.IOException

Description copied from class: FSLinkResolver

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.

Specified by:

next in class FSLinkResolver<T>

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

java.io.IOException - an I/O error occurred

resolve

public static <T> T resolve(FileContext fileContext,
                            Path path,
                            FsLinkResolution.FsLinkResolutionFunction<T> fn)
                     throws UnresolvedLinkException,
                            java.io.IOException

Apply the given function to the resolved path under the the supplied FileContext.

Type Parameters:

T - return type.

Parameters:

fileContext - file context to resolve under

path - path to resolve

fn - function to invoke

Returns:

the return value of the function as revoked against the resolved path.

Throws:

UnresolvedLinkException - link resolution failure

java.io.IOException - other IO failure.