de.unkrig.commons.file.fileprocessing

Class FileProcessings

java.lang.Object

de.unkrig.commons.file.fileprocessing.FileProcessings

public final class FileProcessings
extends java.lang.Object

Various file processing utility methods.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FileProcessings.DirectoryCombiner<T> Transforms the return values of the invocations of directoryMemberProcessor for each member.

Method Summary

Modifier and Type	Method and Description
static <T> FileProcessor<T>	archiveCompressedAndNormalFileProcessor(Predicate<? super java.lang.String> lookIntoFormat, ContentsProcessor<T> archiveContentsProcessor, ContentsProcessings.ArchiveCombiner<T> archiveEntryCombiner, ContentsProcessor<T> compressedContentsProcessor, ContentsProcessor<T> normalContentsProcessor, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileProcessor which processes files by feeding their contents either to the archiveContentsProcessor, the compressedContentsProcessor or the normalContentsProcessor}.
static <T> FileProcessor<T>	directoryProcessor(Predicate<? super java.lang.String> pathPredicate, FileProcessor<T> regularFileProcessor, java.util.Comparator<java.lang.Object> directoryMemberNameComparator, FileProcessor<T> directoryMemberProcessor, FileProcessings.DirectoryCombiner<T> directoryCombiner, SquadExecutor<T> squadExecutor, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileProcessor which processes directories and regular files.
static <T> FileProcessor<T>	directoryTreeProcessor(Predicate<? super java.lang.String> pathPredicate, FileProcessor<T> regularFileProcessor, java.util.Comparator<java.lang.Object> directoryMemberNameComparator, FileProcessings.DirectoryCombiner<T> directoryCombiner, SquadExecutor<T> squadExecutor, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileProcessor which processes directories and regular files exactly like the FileProcessor returned by directoryProcessor(Predicate, FileProcessor, Comparator, FileProcessor, DirectoryCombiner, SquadExecutor, ExceptionHandler), except that it processes directory members recursively.
static <T> FileProcessor<T>	nop()
static <T> FileProcessings.DirectoryCombiner<T>	nopDirectoryCombiner() A FileProcessings.DirectoryCombiner which ignores the combinables and returns null.
static <T> void	process(java.util.List<java.io.File> files, FileProcessor<T> fileProcessor)
static <T> void	process(java.util.List<java.io.File> files, FileProcessor<T> fileProcessor, ExceptionHandler<java.io.IOException> exceptionHandler) Invokes the fileProcessor for each of the files.
static <T> FileProcessor<T>	recursiveCompressedAndArchiveFileProcessor(Predicate<? super java.lang.String> lookIntoFormat, ContentsProcessings.ArchiveCombiner<T> archiveEntryCombiner, ContentsProcessor<T> delegate, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileProcessor which processes files by feeding their contents through the delegate (just like the FileContentsProcessor), but automagically detects various archive and compression formats (also nested) and processes the entries of the archive and the uncompressed contents instead of the "raw" contents.

Methods inherited from class java.lang.Object

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

Method Detail

nop

public static <T> FileProcessor<T> nop()

Returns:

A FileProcessor that does nothing and returns null.

process

public static <T> void process(java.util.List<java.io.File> files,
                               FileProcessor<T> fileProcessor)
                        throws java.io.IOException,
                               java.lang.InterruptedException

Throws:

java.io.IOException

java.lang.InterruptedException

See Also:

process(List, FileProcessor, ExceptionHandler)

process

public static <T> void process(java.util.List<java.io.File> files,
                               FileProcessor<T> fileProcessor,
                               ExceptionHandler<java.io.IOException> exceptionHandler)
                        throws java.io.IOException,
                               java.lang.InterruptedException

Invokes the fileProcessor for each of the files.

Parameters:

exceptionHandler - Called if the processing of one of the inputFiles throws an IOException or a RuntimeException

Throws:

java.io.IOException

java.lang.InterruptedException

directoryTreeProcessor

public static <T> FileProcessor<T> directoryTreeProcessor(Predicate<? super java.lang.String> pathPredicate,
                                                          FileProcessor<T> regularFileProcessor,
                                                          @Nullable
                                                          java.util.Comparator<java.lang.Object> directoryMemberNameComparator,
                                                          FileProcessings.DirectoryCombiner<T> directoryCombiner,
                                                          SquadExecutor<T> squadExecutor,
                                                          ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileProcessor which processes directories and regular files exactly like the FileProcessor returned by directoryProcessor(Predicate, FileProcessor, Comparator, FileProcessor, DirectoryCombiner, SquadExecutor, ExceptionHandler), except that it processes directory members recursively.

Notice that the list passed to the directoryCombiner can contain null values iff the regularFileProcessor returns null values.

Parameters:

directoryMemberNameComparator - The comparator used to sort a directory's members; a null value means to NOT sort the members, i.e. leave them in their 'natural' order as File.list() returns them

See Also:

directoryProcessor(Predicate, FileProcessor, Comparator, FileProcessor, DirectoryCombiner, SquadExecutor, ExceptionHandler)

directoryProcessor

public static <T> FileProcessor<T> directoryProcessor(Predicate<? super java.lang.String> pathPredicate,
                                                      FileProcessor<T> regularFileProcessor,
                                                      @Nullable
                                                      java.util.Comparator<java.lang.Object> directoryMemberNameComparator,
                                                      FileProcessor<T> directoryMemberProcessor,
                                                      FileProcessings.DirectoryCombiner<T> directoryCombiner,
                                                      SquadExecutor<T> squadExecutor,
                                                      ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileProcessor which processes directories and regular files.

Its behavior is as follows:

• Iff the subject file is not a directory, the regularFileProcessor is invoked and its result is returned.
• Otherwise the subject file is a directory.
  • Iff, according to the pathPredicate, the directory can impossibly contain relevant documents, null is returned.
  • Otherwise, the directory members are listed.
  • Iff the directoryMemberNameComparator is not null, the members are sorted according to the directoryMemberNameComparator
  • The directoryMemberProcessor is invoked for each member, and the return values are stored in a list.
  • The directoryCombiner is invoked with that list. (Notice that the list may contain null values iff the directoryMemberProcessor returns null values.)
  • The value produced by the directoryCombiner is returned.

Notice that the pathPredicate is only used to avoid unnecessary directory scans; apart from that the regularFileProcessor and the directoryMemberProcessor are called for any file without further ado.

If you use Void for <T>, then nopDirectoryCombiner() is the right directoryCombiner.

Type Parameters:

T - The return type of all FileProcessor.process(String, File) methods

Parameters:

squadExecutor - Is used to process independent subtrees - could be ConcurrentUtil.SEQUENTIAL_EXECUTOR_SERVICE

directoryMemberNameComparator - The comparator used to sort a directory's members; a null value means to NOT sort the members, i.e. leave them in their 'natural' order as File.list() returns them

nopDirectoryCombiner

public static <T> FileProcessings.DirectoryCombiner<T> nopDirectoryCombiner()

A FileProcessings.DirectoryCombiner which ignores the combinables and returns null.

archiveCompressedAndNormalFileProcessor

public static <T> FileProcessor<T> archiveCompressedAndNormalFileProcessor(Predicate<? super java.lang.String> lookIntoFormat,
                                                                           ContentsProcessor<T> archiveContentsProcessor,
                                                                           ContentsProcessings.ArchiveCombiner<T> archiveEntryCombiner,
                                                                           ContentsProcessor<T> compressedContentsProcessor,
                                                                           ContentsProcessor<T> normalContentsProcessor,
                                                                           ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileProcessor which processes files by feeding their contents either to the archiveContentsProcessor, the compressedContentsProcessor or the normalContentsProcessor}.

Archive files and compressed files are introspected iff lookIntoFormat evaluates true for "format:path".

Parameters:

lookIntoFormat - See CompressUtil.processFile(String, File, Predicate, ArchiveHandler, CompressorHandler, NormalContentsHandler)

recursiveCompressedAndArchiveFileProcessor

public static <T> FileProcessor<T> recursiveCompressedAndArchiveFileProcessor(Predicate<? super java.lang.String> lookIntoFormat,
                                                                              ContentsProcessings.ArchiveCombiner<T> archiveEntryCombiner,
                                                                              ContentsProcessor<T> delegate,
                                                                              ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileProcessor which processes files by feeding their contents through the delegate (just like the FileContentsProcessor), but automagically detects various archive and compression formats (also nested) and processes the entries of the archive and the uncompressed contents instead of the "raw" contents.

Archive files/entries and compressed files/entries are introspected iff lookIntoFormat evaluates true for "format:path".