FileFilterUtils.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.io.filefilter;
import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOCase;
/**
* Useful utilities for working with file filters. It provides access to most
* file filter implementations in this package so you don't have to import
* every class you use.
*
* @since 1.0
*/
public class FileFilterUtils {
/* Constructed on demand and then cached */
private static final IOFileFilter CVS_FILTER = notFileFilter(
and(directoryFileFilter(), nameFileFilter("CVS")));
/* Constructed on demand and then cached */
private static final IOFileFilter SVN_FILTER = notFileFilter(
and(directoryFileFilter(), nameFileFilter(".svn")));
/**
* Returns a filter that returns true if the file was last modified before
* or at the specified cutoff date.
*
* @param cutoffDate the time threshold
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final Date cutoffDate) {
return new AgeFileFilter(cutoffDate);
}
/**
* Returns a filter that filters files based on a cutoff date.
*
* @param cutoffDate the time threshold
* @param acceptOlder if true, older files get accepted, if false, newer
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final Date cutoffDate, final boolean acceptOlder) {
return new AgeFileFilter(cutoffDate, acceptOlder);
}
/**
* Returns a filter that returns true if the file was last modified before
* or at the same time as the specified reference file.
*
* @param cutoffReference the file whose last modification
* time is used as the threshold age of the files
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final File cutoffReference) {
return new AgeFileFilter(cutoffReference);
}
/**
* Returns a filter that filters files based on a cutoff reference file.
*
* @param cutoffReference the file whose last modification
* time is used as the threshold age of the files
* @param acceptOlder if true, older files get accepted, if false, newer
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final File cutoffReference, final boolean acceptOlder) {
return new AgeFileFilter(cutoffReference, acceptOlder);
}
/**
* Returns a filter that returns true if the file was last modified before
* or at the specified cutoff time.
*
* @param cutoffMillis the time threshold
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final long cutoffMillis) {
return new AgeFileFilter(cutoffMillis);
}
/**
* Returns a filter that filters files based on a cutoff time.
*
* @param cutoffMillis the time threshold
* @param acceptOlder if true, older files get accepted, if false, newer
* @return an appropriately configured age file filter
* @see AgeFileFilter
* @since 1.2
*/
public static IOFileFilter ageFileFilter(final long cutoffMillis, final boolean acceptOlder) {
return new AgeFileFilter(cutoffMillis, acceptOlder);
}
/**
* Returns a filter that ANDs the specified filters.
*
* @param filters the IOFileFilters that will be ANDed together.
* @return a filter that ANDs the specified filters
*
* @throws IllegalArgumentException if the filters are null or contain a
* null value.
* @see AndFileFilter
* @since 2.0
*/
public static IOFileFilter and(final IOFileFilter... filters) {
return new AndFileFilter(toList(filters));
}
/**
* Returns a filter that ANDs the two specified filters.
*
* @param filter1 the first filter
* @param filter2 the second filter
* @return a filter that ANDs the two specified filters
* @see #and(IOFileFilter...)
* @see AndFileFilter
* @deprecated use {@link #and(IOFileFilter...)}
*/
@Deprecated
public static IOFileFilter andFileFilter(final IOFileFilter filter1, final IOFileFilter filter2) {
return new AndFileFilter(filter1, filter2);
}
/**
* Returns an {@link IOFileFilter} that wraps the
* {@link FileFilter} instance.
*
* @param filter the filter to be wrapped
* @return a new filter that implements IOFileFilter
* @see DelegateFileFilter
*/
public static IOFileFilter asFileFilter(final FileFilter filter) {
return new DelegateFileFilter(filter);
}
/**
* Returns an {@link IOFileFilter} that wraps the
* {@link FilenameFilter} instance.
*
* @param filter the filter to be wrapped
* @return a new filter that implements IOFileFilter
* @see DelegateFileFilter
*/
public static IOFileFilter asFileFilter(final FilenameFilter filter) {
return new DelegateFileFilter(filter);
}
/**
* Returns a filter that checks if the file is a directory.
*
* @return file filter that accepts only directories and not files
* @see DirectoryFileFilter#DIRECTORY
*/
public static IOFileFilter directoryFileFilter() {
return DirectoryFileFilter.DIRECTORY;
}
/**
* Returns a filter that always returns false.
*
* @return a false filter
* @see FalseFileFilter#FALSE
*/
public static IOFileFilter falseFileFilter() {
return FalseFileFilter.FALSE;
}
/**
* Returns a filter that checks if the file is a file (and not a directory).
*
* @return file filter that accepts only files and not directories
* @see FileFileFilter#INSTANCE
*/
public static IOFileFilter fileFileFilter() {
return FileFileFilter.INSTANCE;
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting array is a subset of the original file list that
* matches the provided filter.
* </p>
*
* <pre>
* Set<File> allFiles = ...
* Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
* FileFilterUtils.suffixFileFilter(".java"));
* </pre>
* @param filter the filter to apply to the set of files.
* @param files the array of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws NullPointerException if the filter is {@code null}
* or {@code files} contains a {@code null} value.
*
* @since 2.0
*/
public static File[] filter(final IOFileFilter filter, final File... files) {
Objects.requireNonNull(filter, "filter");
if (files == null) {
return FileUtils.EMPTY_FILE_ARRAY;
}
return filterFiles(filter, Stream.of(files), Collectors.toList()).toArray(FileUtils.EMPTY_FILE_ARRAY);
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting array is a subset of the original file list that
* matches the provided filter.
* </p>
*
* <p>
* The {@link Set} returned by this method is not guaranteed to be thread safe.
* </p>
*
* <pre>
* Set<File> allFiles = ...
* Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
* FileFilterUtils.suffixFileFilter(".java"));
* </pre>
* @param filter the filter to apply to the set of files.
* @param files the array of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws IllegalArgumentException if the filter is {@code null}
* or {@code files} contains a {@code null} value.
*
* @since 2.0
*/
public static File[] filter(final IOFileFilter filter, final Iterable<File> files) {
return filterList(filter, files).toArray(FileUtils.EMPTY_FILE_ARRAY);
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File} stream and collects the accepted files.
* </p>
*
* @param filter the filter to apply to the stream of files.
* @param stream the stream of files on which to apply the filter.
* @param collector how to collect the end result.
*
* @param <R> the return type.
* @param <A> the mutable accumulation type of the reduction operation (often hidden as an implementation detail)
* @return a subset of files from the stream that is accepted by the filter.
* @throws NullPointerException if the filter is {@code null}.
*/
private static <R, A> R filterFiles(final IOFileFilter filter, final Stream<File> stream,
final Collector<? super File, A, R> collector) {
Objects.requireNonNull(filter, "filter");
Objects.requireNonNull(collector, "collector");
if (stream == null) {
return Stream.<File>empty().collect(collector);
}
return stream.filter(filter::accept).collect(collector);
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting list is a subset of the original files that
* matches the provided filter.
* </p>
*
* <p>
* The {@link List} returned by this method is not guaranteed to be thread safe.
* </p>
*
* <pre>
* List<File> filesAndDirectories = ...
* List<File> directories = FileFilterUtils.filterList(filesAndDirectories,
* FileFilterUtils.directoryFileFilter());
* </pre>
* @param filter the filter to apply to each files in the list.
* @param files the collection of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws IllegalArgumentException if the filter is {@code null}
* or {@code files} contains a {@code null} value.
* @since 2.0
*/
public static List<File> filterList(final IOFileFilter filter, final File... files) {
return Arrays.asList(filter(filter, files));
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting list is a subset of the original files that
* matches the provided filter.
* </p>
*
* <p>
* The {@link List} returned by this method is not guaranteed to be thread safe.
* </p>
*
* <pre>
* List<File> filesAndDirectories = ...
* List<File> directories = FileFilterUtils.filterList(filesAndDirectories,
* FileFilterUtils.directoryFileFilter());
* </pre>
* @param filter the filter to apply to each files in the list.
* @param files the collection of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws IllegalArgumentException if the filter is {@code null}
* @since 2.0
*/
public static List<File> filterList(final IOFileFilter filter, final Iterable<File> files) {
if (files == null) {
return Collections.emptyList();
}
return filterFiles(filter, StreamSupport.stream(files.spliterator(), false), Collectors.toList());
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting set is a subset of the original file list that
* matches the provided filter.
* </p>
*
* <p>
* The {@link Set} returned by this method is not guaranteed to be thread safe.
* </p>
*
* <pre>
* Set<File> allFiles = ...
* Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
* FileFilterUtils.suffixFileFilter(".java"));
* </pre>
* @param filter the filter to apply to the set of files.
* @param files the collection of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws IllegalArgumentException if the filter is {@code null}
* or {@code files} contains a {@code null} value.
*
* @since 2.0
*/
public static Set<File> filterSet(final IOFileFilter filter, final File... files) {
return new HashSet<>(Arrays.asList(filter(filter, files)));
}
/**
* <p>
* Applies an {@link IOFileFilter} to the provided {@link File}
* objects. The resulting set is a subset of the original file list that
* matches the provided filter.
* </p>
*
* <p>
* The {@link Set} returned by this method is not guaranteed to be thread safe.
* </p>
*
* <pre>
* Set<File> allFiles = ...
* Set<File> javaFiles = FileFilterUtils.filterSet(allFiles,
* FileFilterUtils.suffixFileFilter(".java"));
* </pre>
* @param filter the filter to apply to the set of files.
* @param files the collection of files to apply the filter to.
*
* @return a subset of {@code files} that is accepted by the
* file filter.
* @throws IllegalArgumentException if the filter is {@code null}
*
* @since 2.0
*/
public static Set<File> filterSet(final IOFileFilter filter, final Iterable<File> files) {
if (files == null) {
return Collections.emptySet();
}
return filterFiles(filter, StreamSupport.stream(files.spliterator(), false), Collectors.toSet());
}
/**
* Returns a filter that accepts files that begin with the provided magic
* number.
*
* @param magicNumber the magic number (byte sequence) to match at the
* beginning of each file.
*
* @return an IOFileFilter that accepts files beginning with the provided
* magic number.
*
* @throws IllegalArgumentException if {@code magicNumber} is
* {@code null} or is of length zero.
* @see MagicNumberFileFilter
* @since 2.0
*/
public static IOFileFilter magicNumberFileFilter(final byte[] magicNumber) {
return new MagicNumberFileFilter(magicNumber);
}
/**
* Returns a filter that accepts files that contains the provided magic
* number at a specified offset within the file.
*
* @param magicNumber the magic number (byte sequence) to match at the
* provided offset in each file.
* @param offset the offset within the files to look for the magic number.
*
* @return an IOFileFilter that accepts files containing the magic number
* at the specified offset.
*
* @throws IllegalArgumentException if {@code magicNumber} is
* {@code null}, or contains no bytes, or {@code offset}
* is a negative number.
* @see MagicNumberFileFilter
* @since 2.0
*/
public static IOFileFilter magicNumberFileFilter(final byte[] magicNumber, final long offset) {
return new MagicNumberFileFilter(magicNumber, offset);
}
/**
* Returns a filter that accepts files that begin with the provided magic
* number.
*
* @param magicNumber the magic number (byte sequence) to match at the
* beginning of each file.
*
* @return an IOFileFilter that accepts files beginning with the provided
* magic number.
*
* @throws IllegalArgumentException if {@code magicNumber} is
* {@code null} or the empty String.
* @see MagicNumberFileFilter
* @since 2.0
*/
public static IOFileFilter magicNumberFileFilter(final String magicNumber) {
return new MagicNumberFileFilter(magicNumber);
}
/**
* Returns a filter that accepts files that contains the provided magic
* number at a specified offset within the file.
*
* @param magicNumber the magic number (byte sequence) to match at the
* provided offset in each file.
* @param offset the offset within the files to look for the magic number.
*
* @return an IOFileFilter that accepts files containing the magic number
* at the specified offset.
*
* @throws IllegalArgumentException if {@code magicNumber} is
* {@code null} or the empty String, or if offset is a
* negative number.
* @see MagicNumberFileFilter
* @since 2.0
*/
public static IOFileFilter magicNumberFileFilter(final String magicNumber, final long offset) {
return new MagicNumberFileFilter(magicNumber, offset);
}
/**
* Decorates a filter to make it ignore CVS directories.
* Passing in {@code null} will return a filter that accepts everything
* except CVS directories.
*
* @param filter the filter to decorate, null means an unrestricted filter
* @return the decorated filter, never null
* @since 1.1 (method existed but had a bug in 1.0)
*/
public static IOFileFilter makeCVSAware(final IOFileFilter filter) {
return filter == null ? CVS_FILTER : and(filter, CVS_FILTER);
}
/**
* Decorates a filter so that it only applies to directories and not to files.
*
* @param filter the filter to decorate, null means an unrestricted filter
* @return the decorated filter, never null
* @see DirectoryFileFilter#DIRECTORY
* @since 1.3
*/
public static IOFileFilter makeDirectoryOnly(final IOFileFilter filter) {
if (filter == null) {
return DirectoryFileFilter.DIRECTORY;
}
return DirectoryFileFilter.DIRECTORY.and(filter);
}
/**
* Decorates a filter so that it only applies to files and not to directories.
*
* @param filter the filter to decorate, null means an unrestricted filter
* @return the decorated filter, never null
* @see FileFileFilter#INSTANCE
* @since 1.3
*/
public static IOFileFilter makeFileOnly(final IOFileFilter filter) {
if (filter == null) {
return FileFileFilter.INSTANCE;
}
return FileFileFilter.INSTANCE.and(filter);
}
/**
* Decorates a filter to make it ignore SVN directories.
* Passing in {@code null} will return a filter that accepts everything
* except SVN directories.
*
* @param filter the filter to decorate, null means an unrestricted filter
* @return the decorated filter, never null
* @since 1.1
*/
public static IOFileFilter makeSVNAware(final IOFileFilter filter) {
return filter == null ? SVN_FILTER : and(filter, SVN_FILTER);
}
/**
* Returns a filter that returns true if the file name matches the specified text.
*
* @param name the file name
* @return a name checking filter
* @see NameFileFilter
*/
public static IOFileFilter nameFileFilter(final String name) {
return new NameFileFilter(name);
}
/**
* Returns a filter that returns true if the file name matches the specified text.
*
* @param name the file name
* @param ioCase how to handle case sensitivity, null means case-sensitive
* @return a name checking filter
* @see NameFileFilter
* @since 2.0
*/
public static IOFileFilter nameFileFilter(final String name, final IOCase ioCase) {
return new NameFileFilter(name, ioCase);
}
/**
* Returns a filter that NOTs the specified filter.
*
* @param filter the filter to invert
* @return a filter that NOTs the specified filter
* @see NotFileFilter
*/
public static IOFileFilter notFileFilter(final IOFileFilter filter) {
return filter.negate();
}
/**
* Returns a filter that ORs the specified filters.
*
* @param filters the IOFileFilters that will be ORed together.
* @return a filter that ORs the specified filters
*
* @throws IllegalArgumentException if the filters are null or contain a
* null value.
* @see OrFileFilter
* @since 2.0
*/
public static IOFileFilter or(final IOFileFilter... filters) {
return new OrFileFilter(toList(filters));
}
/**
* Returns a filter that ORs the two specified filters.
*
* @param filter1 the first filter
* @param filter2 the second filter
* @return a filter that ORs the two specified filters
* @see #or(IOFileFilter...)
* @see OrFileFilter
* @deprecated use {@link #or(IOFileFilter...)}
*/
@Deprecated
public static IOFileFilter orFileFilter(final IOFileFilter filter1, final IOFileFilter filter2) {
return new OrFileFilter(filter1, filter2);
}
/**
* Returns a filter that returns true if the file name starts with the specified text.
*
* @param prefix the file name prefix
* @return a prefix checking filter
* @see PrefixFileFilter
*/
public static IOFileFilter prefixFileFilter(final String prefix) {
return new PrefixFileFilter(prefix);
}
/**
* Returns a filter that returns true if the file name starts with the specified text.
*
* @param prefix the file name prefix
* @param ioCase how to handle case sensitivity, null means case-sensitive
* @return a prefix checking filter
* @see PrefixFileFilter
* @since 2.0
*/
public static IOFileFilter prefixFileFilter(final String prefix, final IOCase ioCase) {
return new PrefixFileFilter(prefix, ioCase);
}
/**
* Returns a filter that returns true if the file is bigger than a certain size.
*
* @param threshold the file size threshold
* @return an appropriately configured SizeFileFilter
* @see SizeFileFilter
* @since 1.2
*/
public static IOFileFilter sizeFileFilter(final long threshold) {
return new SizeFileFilter(threshold);
}
/**
* Returns a filter that filters based on file size.
*
* @param threshold the file size threshold
* @param acceptLarger if true, larger files get accepted, if false, smaller
* @return an appropriately configured SizeFileFilter
* @see SizeFileFilter
* @since 1.2
*/
public static IOFileFilter sizeFileFilter(final long threshold, final boolean acceptLarger) {
return new SizeFileFilter(threshold, acceptLarger);
}
/**
* Returns a filter that accepts files whose size is >= minimum size
* and <= maximum size.
*
* @param minSizeInclusive the minimum file size (inclusive)
* @param maxSizeInclusive the maximum file size (inclusive)
* @return an appropriately configured IOFileFilter
* @see SizeFileFilter
* @since 1.3
*/
public static IOFileFilter sizeRangeFileFilter(final long minSizeInclusive, final long maxSizeInclusive ) {
final IOFileFilter minimumFilter = new SizeFileFilter(minSizeInclusive, true);
final IOFileFilter maximumFilter = new SizeFileFilter(maxSizeInclusive + 1L, false);
return minimumFilter.and(maximumFilter);
}
/**
* Returns a filter that returns true if the file name ends with the specified text.
*
* @param suffix the file name suffix
* @return a suffix checking filter
* @see SuffixFileFilter
*/
public static IOFileFilter suffixFileFilter(final String suffix) {
return new SuffixFileFilter(suffix);
}
/**
* Returns a filter that returns true if the file name ends with the specified text.
*
* @param suffix the file name suffix
* @param ioCase how to handle case sensitivity, null means case-sensitive
* @return a suffix checking filter
* @see SuffixFileFilter
* @since 2.0
*/
public static IOFileFilter suffixFileFilter(final String suffix, final IOCase ioCase) {
return new SuffixFileFilter(suffix, ioCase);
}
/**
* Create a List of file filters.
*
* @param filters The file filters
* @return The list of file filters
* @throws NullPointerException if the filters are null or contain a
* null value.
* @since 2.0
*/
public static List<IOFileFilter> toList(final IOFileFilter... filters) {
return Stream.of(Objects.requireNonNull(filters, "filters")).map(Objects::requireNonNull).collect(Collectors.toList());
}
/**
* Returns a filter that always returns true.
*
* @return a true filter
* @see TrueFileFilter#TRUE
*/
public static IOFileFilter trueFileFilter() {
return TrueFileFilter.TRUE;
}
/**
* FileFilterUtils is not normally instantiated.
*/
public FileFilterUtils() {
}
}