/*
* 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.google.common.io;
import com.google.common.annotations.Beta;
import com.google.common.base.Preconditions;
import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import javax.annotation.Nullable;
/**
* 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
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);
}
@Override public boolean accept(@Nullable File dir, String fileName) {
return pattern.matcher(fileName).matches();
}
}
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