de.unkrig.commons.file.filetransformation

Class FileTransformations

java.lang.Object

de.unkrig.commons.file.filetransformation.FileTransformations

public final class FileTransformations
extends java.lang.Object

Various FileTransformer-related utility methods.

A typical application is to wrap file transformers and content transformers as follows:

              |
              v
     directoryTreeTransformer()
              |
              v
     recursiveCompressedAndArchiveFileTransformer()
              |
              v
     (some contents fransformer, e.g. 'ContentsTransformerUtil.NOP')
 

The directoryTreeTransformer()) can be left out if you don't need recursive directory traversal.

The recursiveCompressedAndArchiveFileTransformer() can be left out if you don't want to look into archives nor compressed files.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FileTransformations.ArchiveCombiner
static interface	FileTransformations.DirectoryCombiner
static interface	FileTransformations.NameAndContents

Field Summary

Fields

Modifier and Type	Field and Description
static FileTransformer	UNCHANGED If in equals out ("in-place transformation"), then file is left untouched.

Method Summary

Modifier and Type	Method and Description
static FileTransformer	compressedAndArchiveFileTransformer(Predicate<? super java.lang.String> lookIntoFormat, Predicate<? super java.lang.String> archiveEntryRemoval, Glob archiveEntryRenaming, FileTransformations.ArchiveCombiner archiveCombiner, ContentsTransformer archiveEntryContentsTransformer, ContentsTransformer compressedContentsTransformer, ContentsTransformer normalContentsTransformer, boolean keepOriginals, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileTransformer which transforms files by feeding their contents through the normalContentsTransformer (just like the FileContentsTransformer), or, iff the file is an archive file, by feeding the archive file's entries through the archiveEntryContentsTransformer, or, iff the file is a compressed file, be feeding the compressed file's decompressed contents through the compressedContentsTransformer.
static DirectoryTransformer	directoryTreeTransformer(java.util.Comparator<java.lang.Object> directoryMemberNameComparator, Predicate<? super java.lang.String> directoryMemberRemoval, Glob directoryMemberRenaming, FileTransformations.DirectoryCombiner directoryCombiner, FileTransformer regularFileTransformer, boolean saveSpace, boolean keepOriginals, ExceptionHandler<java.io.IOException> exceptionHandler) Creates and returns a DirectoryTransformer which implements the following features: Recursive processing of directories Removal, renaming and addition of directory members
static java.io.File	newFile(java.io.File file)
static java.io.File	origFile(java.io.File file)
static FileTransformer	recursiveCompressedAndArchiveFileTransformer(Predicate<? super java.lang.String> lookIntoFormat, Predicate<? super java.lang.String> archiveEntryRemoval, Glob archiveEntryRenaming, FileTransformations.ArchiveCombiner archiveCombiner, ContentsTransformer delegate, boolean keepOriginals, ExceptionHandler<java.io.IOException> exceptionHandler) Returns a FileTransformer which transforms files by feeding their contents through the delegate (just like the FileContentsTransformer), 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.
static FileTransformer	remove() If in equals out ("in-place transformation"), then file in is deleted.
static FileTransformer	renameRemoveFileTransformer(Predicate<? super java.lang.String> removal, Glob renaming, FileTransformer delegate, boolean keepOriginals) Wraps the given delegate in a FileTransformer which handles removal and renaming of files.
static void	transform(java.lang.String[] args, FileTransformer fileTransformer, FileTransformer.Mode mode, ExceptionHandler<java.io.IOException> exceptionHandler) Transforms a set of files based on an array of strings, similar to many UNIX™ command line tools.

Methods inherited from class java.lang.Object

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

Field Detail

UNCHANGED

public static final FileTransformer UNCHANGED

If in equals out ("in-place transformation"), then file is left untouched. Otherwise ("out-of-place transformation") in is copied byte-by-byte to out.

Method Detail

remove

public static FileTransformer remove()

If in equals out ("in-place transformation"), then file in is deleted. Otherwise ("out-of-place transformation") nothing is done, i.e. a file out is not created.

directoryTreeTransformer

public static DirectoryTransformer directoryTreeTransformer(@Nullable
                                                            java.util.Comparator<java.lang.Object> directoryMemberNameComparator,
                                                            Predicate<? super java.lang.String> directoryMemberRemoval,
                                                            Glob directoryMemberRenaming,
                                                            FileTransformations.DirectoryCombiner directoryCombiner,
                                                            FileTransformer regularFileTransformer,
                                                            boolean saveSpace,
                                                            boolean keepOriginals,
                                                            ExceptionHandler<java.io.IOException> exceptionHandler)

Creates and returns a DirectoryTransformer which implements the following features:

• Recursive processing of directories
• Removal, renaming and addition of directory members

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

directoryMemberRemoval - Whether to remove (i.e. not copy) a member; the subject is the path of the member

directoryMemberRenaming - Transforms the name of a member

saveSpace - If true, then the method attempts to save file system space for in-place transformations by transforming each file, otherwise it creates a copy of the entire directory tree before deleting the original

renameRemoveFileTransformer

public static FileTransformer renameRemoveFileTransformer(Predicate<? super java.lang.String> removal,
                                                          Glob renaming,
                                                          FileTransformer delegate,
                                                          boolean keepOriginals)

Wraps the given delegate in a FileTransformer which handles removal and renaming of files.

Returns:

A file transformer which implements removal and renaming of files.

compressedAndArchiveFileTransformer

public static FileTransformer compressedAndArchiveFileTransformer(Predicate<? super java.lang.String> lookIntoFormat,
                                                                  Predicate<? super java.lang.String> archiveEntryRemoval,
                                                                  Glob archiveEntryRenaming,
                                                                  FileTransformations.ArchiveCombiner archiveCombiner,
                                                                  ContentsTransformer archiveEntryContentsTransformer,
                                                                  ContentsTransformer compressedContentsTransformer,
                                                                  ContentsTransformer normalContentsTransformer,
                                                                  boolean keepOriginals,
                                                                  ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileTransformer which transforms files by feeding their contents through the normalContentsTransformer (just like the FileContentsTransformer), or, iff the file is an archive file, by feeding the archive file's entries through the archiveEntryContentsTransformer, or, iff the file is a compressed file, be feeding the compressed file's decompressed contents through the compressedContentsTransformer.

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

recursiveCompressedAndArchiveFileTransformer

public static FileTransformer recursiveCompressedAndArchiveFileTransformer(Predicate<? super java.lang.String> lookIntoFormat,
                                                                           Predicate<? super java.lang.String> archiveEntryRemoval,
                                                                           Glob archiveEntryRenaming,
                                                                           FileTransformations.ArchiveCombiner archiveCombiner,
                                                                           ContentsTransformer delegate,
                                                                           boolean keepOriginals,
                                                                           ExceptionHandler<java.io.IOException> exceptionHandler)

Returns a FileTransformer which transforms files by feeding their contents through the delegate (just like the FileContentsTransformer), 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.

Parameters:

lookIntoFormat - Whether the file/entry should be introspected; the subject is "format:container-path"

archiveEntryRemoval - Whether to remove (i.e. not copy) a subject file or an archive entry; the subject is the path of the subject file resp. the archive entry

archiveEntryRenaming - Transforms the name of a subject file or an archive entry

archiveCombiner - Is invoked after the processing of each archive

transform

public static void transform(java.lang.String[] args,
                             FileTransformer fileTransformer,
                             FileTransformer.Mode mode,
                             ExceptionHandler<java.io.IOException> exceptionHandler)
                      throws java.io.IOException

Transforms a set of files based on an array of strings, similar to many UNIX™ command line tools.

If args.length == 1, then the file or directory args[0] is transformed in-place.

If args.length == 2 and args[1] is not an existing directory, then the file args[0] is transformed into the file args[1].

If args.length >= 2 and args[args.length - 1] is an existing directory, then the files args[0] ... args[args.length - 2] are transformed into files with the same names in the directory args[args.length - 1].

Parameters:

exceptionHandler - If the transformation of one of the inputFiles throws an IOException or a RuntimeException, then ExceptionHandler.handle(String, Exception) resp. ExceptionHandler.handle(String, RuntimeException) is called. Iff that call completes normally, then processing continues with the next inputFile.

Throws:

java.io.IOException - args.length == 0

java.io.IOException - args.length > 2 and args[args.length - 1] is not an existing directory

newFile

public static java.io.File newFile(java.io.File file)

Returns:

A file derived from the file which is typically used to create a temporary file which is later renamed to replace some "original" file

origFile

public static java.io.File origFile(java.io.File file)

Returns:

A file derived from the file which is typically used as a container to keep an "original" file