CountingPathVisitor.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.file;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Objects;
import java.util.function.UnaryOperator;
import org.apache.commons.io.file.Counters.PathCounters;
import org.apache.commons.io.filefilter.IOFileFilter;
import org.apache.commons.io.filefilter.SymbolicLinkFileFilter;
import org.apache.commons.io.filefilter.TrueFileFilter;
import org.apache.commons.io.function.IOBiFunction;
/**
* Counts files, directories, and sizes, as a visit proceeds.
*
* @since 2.7
*/
public class CountingPathVisitor extends SimplePathVisitor {
/**
* Builds instances of {@link CountingPathVisitor}.
*
* @param <T> The CountingPathVisitor type.
* @param <B> The AbstractBuilder type.
* @since 2.19.0
*/
public abstract static class AbstractBuilder<T, B extends AbstractBuilder<T, B>> extends SimplePathVisitor.AbstractBuilder<T, B> {
private PathCounters pathCounters = defaultPathCounters();
private PathFilter fileFilter = defaultFileFilter();
private PathFilter directoryFilter = defaultDirectoryFilter();
private UnaryOperator<Path> directoryPostTransformer = defaultDirectoryTransformer();
/**
* Constructs a new builder for subclasses.
*/
public AbstractBuilder() {
// empty.
}
PathFilter getDirectoryFilter() {
return directoryFilter;
}
UnaryOperator<Path> getDirectoryPostTransformer() {
return directoryPostTransformer;
}
PathFilter getFileFilter() {
return fileFilter;
}
PathCounters getPathCounters() {
return pathCounters;
}
/**
* Sets how to filter directories.
*
* @param directoryFilter how to filter files.
* @return this instance.
*/
public B setDirectoryFilter(final PathFilter directoryFilter) {
this.directoryFilter = directoryFilter != null ? directoryFilter : defaultDirectoryFilter();
return asThis();
}
/**
* Sets how to transform directories, defaults to {@link UnaryOperator#identity()}.
*
* @param directoryTransformer how to filter files.
* @return this instance.
*/
public B setDirectoryPostTransformer(final UnaryOperator<Path> directoryTransformer) {
this.directoryPostTransformer = directoryTransformer != null ? directoryTransformer : defaultDirectoryTransformer();
return asThis();
}
/**
* Sets how to filter files.
*
* @param fileFilter how to filter files.
* @return this instance.
*/
public B setFileFilter(final PathFilter fileFilter) {
this.fileFilter = fileFilter != null ? fileFilter : defaultFileFilter();
return asThis();
}
/**
* Sets how to count path visits.
*
* @param pathCounters How to count path visits.
* @return this instance.
*/
public B setPathCounters(final PathCounters pathCounters) {
this.pathCounters = pathCounters != null ? pathCounters : defaultPathCounters();
return asThis();
}
}
/**
* Builds instances of {@link CountingPathVisitor}.
*
* @since 2.18.0
*/
public static class Builder extends AbstractBuilder<CountingPathVisitor, Builder> {
/**
* Constructs a new builder.
*/
public Builder() {
// empty.
}
@Override
public CountingPathVisitor get() {
return new CountingPathVisitor(this);
}
}
static final String[] EMPTY_STRING_ARRAY = {};
static IOFileFilter defaultDirectoryFilter() {
return TrueFileFilter.INSTANCE;
}
static UnaryOperator<Path> defaultDirectoryTransformer() {
return UnaryOperator.identity();
}
static IOFileFilter defaultFileFilter() {
return new SymbolicLinkFileFilter(FileVisitResult.TERMINATE, FileVisitResult.CONTINUE);
}
static PathCounters defaultPathCounters() {
return Counters.longPathCounters();
}
/**
* Constructs a new instance configured with a {@link BigInteger} {@link PathCounters}.
*
* @return a new instance configured with a {@link BigInteger} {@link PathCounters}.
*/
public static CountingPathVisitor withBigIntegerCounters() {
return new Builder().setPathCounters(Counters.bigIntegerPathCounters()).get();
}
/**
* Constructs a new instance configured with a {@code long} {@link PathCounters}.
*
* @return a new instance configured with a {@code long} {@link PathCounters}.
*/
public static CountingPathVisitor withLongCounters() {
return new Builder().setPathCounters(Counters.longPathCounters()).get();
}
private final PathCounters pathCounters;
private final PathFilter fileFilter;
private final PathFilter directoryFilter;
private final UnaryOperator<Path> directoryPostTransformer;
CountingPathVisitor(final AbstractBuilder<?, ?> builder) {
super(builder);
this.pathCounters = builder.getPathCounters();
this.fileFilter = builder.getFileFilter();
this.directoryFilter = builder.getDirectoryFilter();
this.directoryPostTransformer = builder.getDirectoryPostTransformer();
}
/**
* Constructs a new instance.
*
* @param pathCounters How to count path visits.
* @see Builder
*/
public CountingPathVisitor(final PathCounters pathCounters) {
this(new Builder().setPathCounters(pathCounters));
}
/**
* Constructs a new instance.
*
* @param pathCounters How to count path visits.
* @param fileFilter Filters which files to count.
* @param directoryFilter Filters which directories to count.
* @see Builder
* @since 2.9.0
*/
public CountingPathVisitor(final PathCounters pathCounters, final PathFilter fileFilter, final PathFilter directoryFilter) {
this.pathCounters = Objects.requireNonNull(pathCounters, "pathCounters");
this.fileFilter = Objects.requireNonNull(fileFilter, "fileFilter");
this.directoryFilter = Objects.requireNonNull(directoryFilter, "directoryFilter");
this.directoryPostTransformer = UnaryOperator.identity();
}
/**
* Constructs a new instance.
*
* @param pathCounters How to count path visits.
* @param fileFilter Filters which files to count.
* @param directoryFilter Filters which directories to count.
* @param visitFileFailed Called on {@link #visitFileFailed(Path, IOException)}.
* @since 2.12.0
* @deprecated Use {@link Builder}.
*/
@Deprecated
public CountingPathVisitor(final PathCounters pathCounters, final PathFilter fileFilter, final PathFilter directoryFilter,
final IOBiFunction<Path, IOException, FileVisitResult> visitFileFailed) {
super(visitFileFailed);
this.pathCounters = Objects.requireNonNull(pathCounters, "pathCounters");
this.fileFilter = Objects.requireNonNull(fileFilter, "fileFilter");
this.directoryFilter = Objects.requireNonNull(directoryFilter, "directoryFilter");
this.directoryPostTransformer = UnaryOperator.identity();
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof CountingPathVisitor)) {
return false;
}
final CountingPathVisitor other = (CountingPathVisitor) obj;
return Objects.equals(pathCounters, other.pathCounters);
}
/**
* Gets the visitation counts.
*
* @return the visitation counts.
*/
public PathCounters getPathCounters() {
return pathCounters;
}
@Override
public int hashCode() {
return Objects.hash(pathCounters);
}
@Override
public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
updateDirCounter(directoryPostTransformer.apply(dir), exc);
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attributes) throws IOException {
final FileVisitResult accept = directoryFilter.accept(dir, attributes);
return accept != FileVisitResult.CONTINUE ? FileVisitResult.SKIP_SUBTREE : FileVisitResult.CONTINUE;
}
@Override
public String toString() {
return pathCounters.toString();
}
/**
* Updates the counter for visiting the given directory.
*
* @param dir the visited directory.
* @param exc Encountered exception.
* @since 2.9.0
*/
protected void updateDirCounter(final Path dir, final IOException exc) {
pathCounters.getDirectoryCounter().increment();
}
/**
* Updates the counters for visiting the given file.
*
* @param file the visited file.
* @param attributes the visited file attributes.
*/
protected void updateFileCounters(final Path file, final BasicFileAttributes attributes) {
pathCounters.getFileCounter().increment();
pathCounters.getByteCounter().add(attributes.size());
}
@Override
public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
// Note: A file can be a symbolic link to a directory.
if (Files.exists(file) && fileFilter.accept(file, attributes) == FileVisitResult.CONTINUE) {
updateFileCounters(file, attributes);
}
return FileVisitResult.CONTINUE;
}
}