com.github.lontime.shaded.com.google.common.io.PatternFilenameFilter Maven / Gradle / Ivy
/*
* Copyright (C) 2006 The Guava Authors
*
* Licensed 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 com.github.lontime.shaded.com.google.common.io;
import com.github.lontime.shaded.com.google.common.annotations.Beta;
import com.github.lontime.shaded.com.google.common.annotations.GwtIncompatible;
import com.github.lontime.shaded.com.google.common.base.Preconditions;
import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
/**
* File name filter that only accepts files matching a regular expression. This class is thread-safe
* and immutable.
*
* @author Apple Chow
* @since 1.0
*/
@Beta
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PatternFilenameFilter implements FilenameFilter {
private final Pattern pattern;
/**
* Constructs a pattern file name filter object.
*
* @param patternStr the pattern string on which to filter file names
* @throws PatternSyntaxException if pattern compilation fails (runtime)
*/
public PatternFilenameFilter(String patternStr) {
this(Pattern.compile(patternStr));
}
/**
* Constructs a pattern file name filter object.
*
* @param pattern the pattern on which to filter file names
*/
public PatternFilenameFilter(Pattern pattern) {
this.pattern = Preconditions.checkNotNull(pattern);
}
/*
* Our implementation works fine with a null `dir`. However, there's nothing in the documentation
* of the supertype that suggests that implementations are expected to tolerate null. That said, I
* see calls in Google code that pass a null `dir` to a FilenameFilter.... So let's declare the
* parameter as non-nullable (since passing null to a FilenameFilter is unsafe in general), but if
* someone still manages to pass null, let's continue to have the method work.
*
* (PatternFilenameFilter is of course one of those classes that shouldn't be a publicly visible
* class to begin with but rather something returned from a static factory method whose declared
* return type is plain FilenameFilter. If we made such a change, then the annotation we choose
* here would have no significance to end users, who would be forced to conform to the signature
* used in FilenameFilter.)
*/
@Override
public boolean accept(File dir, String fileName) {
return pattern.matcher(fileName).matches();
}
}