/*
* 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.Serializable;
import java.util.List;
import org.apache.commons.io.IOCase;
/**
* Filters filenames for a certain prefix.
* <p>
* For example, to print all files and directories in the
* current directory whose name starts with <code>Test</code>:
*
* <pre>
* File dir = new File(".");
* String[] files = dir.list( new PrefixFileFilter("Test") );
* for ( int i = 0; i < files.length; i++ ) {
* System.out.println(files[i]);
* }
* </pre>
*
* @since 1.0
* @version $Id: PrefixFileFilter.java 1304052 2012-03-22 20:55:29Z ggregory $
* @see FileFilterUtils#prefixFileFilter(String)
* @see FileFilterUtils#prefixFileFilter(String, IOCase)
*/
public class PrefixFileFilter extends AbstractFileFilter implements Serializable {
/** The filename prefixes to search for */
private final String[] prefixes;
/** Whether the comparison is case sensitive. */
private final IOCase caseSensitivity;
/**
* Constructs a new Prefix file filter for a single prefix.
*
* @param prefix the prefix to allow, must not be null
* @throws IllegalArgumentException if the prefix is null
*/
public PrefixFileFilter(String prefix) {
this(prefix, IOCase.SENSITIVE);
}
/**
* Constructs a new Prefix file filter for a single prefix
* specifying case-sensitivity.
*
* @param prefix the prefix to allow, must not be null
* @param caseSensitivity how to handle case sensitivity, null means case-sensitive
* @throws IllegalArgumentException if the prefix is null
* @since 1.4
*/
public PrefixFileFilter(String prefix, IOCase caseSensitivity) {
if (prefix == null) {
throw new IllegalArgumentException("The prefix must not be null");
}
this.prefixes = new String[] {prefix};
this.caseSensitivity = caseSensitivity == null ? IOCase.SENSITIVE : caseSensitivity;
}
/**
* Constructs a new Prefix file filter for any of an array of prefixes.
* <p>
* The array is not cloned, so could be changed after constructing the
* instance. This would be inadvisable however.
*
* @param prefixes the prefixes to allow, must not be null
* @throws IllegalArgumentException if the prefix array is null
*/
public PrefixFileFilter(String[] prefixes) {
this(prefixes, IOCase.SENSITIVE);
}
/**
* Constructs a new Prefix file filter for any of an array of prefixes
* specifying case-sensitivity.
* <p>
* The array is not cloned, so could be changed after constructing the
* instance. This would be inadvisable however.
*
* @param prefixes the prefixes to allow, must not be null
* @param caseSensitivity how to handle case sensitivity, null means case-sensitive
* @throws IllegalArgumentException if the prefix is null
* @since 1.4
*/
public PrefixFileFilter(String[] prefixes, IOCase caseSensitivity) {
if (prefixes == null) {
throw new IllegalArgumentException("The array of prefixes must not be null");
}
this.prefixes = new String[prefixes.length];
System.arraycopy(prefixes, 0, this.prefixes, 0, prefixes.length);
this.caseSensitivity = caseSensitivity == null ? IOCase.SENSITIVE : caseSensitivity;
}
/**
* Constructs a new Prefix file filter for a list of prefixes.
*
* @param prefixes the prefixes to allow, must not be null
* @throws IllegalArgumentException if the prefix list is null
* @throws ClassCastException if the list does not contain Strings
*/
public PrefixFileFilter(List<String> prefixes) {
this(prefixes, IOCase.SENSITIVE);
}
/**
* Constructs a new Prefix file filter for a list of prefixes
* specifying case-sensitivity.
*
* @param prefixes the prefixes to allow, must not be null
* @param caseSensitivity how to handle case sensitivity, null means case-sensitive
* @throws IllegalArgumentException if the prefix list is null
* @throws ClassCastException if the list does not contain Strings
* @since 1.4
*/
public PrefixFileFilter(List<String> prefixes, IOCase caseSensitivity) {
if (prefixes == null) {
throw new IllegalArgumentException("The list of prefixes must not be null");
}
this.prefixes = prefixes.toArray(new String[prefixes.size()]);
this.caseSensitivity = caseSensitivity == null ? IOCase.SENSITIVE : caseSensitivity;
}
/**
* Checks to see if the filename starts with the prefix.
*
* @param file the File to check
* @return true if the filename starts with one of our prefixes
*/
@Override
public boolean accept(File file) {
String name = file.getName();
for (String prefix : this.prefixes) {
if (caseSensitivity.checkStartsWith(name, prefix)) {
return true;
}
}
return false;
}
/**
* Checks to see if the filename starts with the prefix.
*
* @param file the File directory
* @param name the filename
* @return true if the filename starts with one of our prefixes
*/
@Override
public boolean accept(File file, String name) {
for (String prefix : prefixes) {
if (caseSensitivity.checkStartsWith(name, prefix)) {
return true;
}
}
return false;
}
/**
* Provide a String representaion of this file filter.
*
* @return a String representaion
*/
@Override
public String toString() {
StringBuilder buffer = new StringBuilder();
buffer.append(super.toString());
buffer.append("(");
if (prefixes != null) {
for (int i = 0; i < prefixes.length; i++) {
if (i > 0) {
buffer.append(",");
}
buffer.append(prefixes[i]);
}
}
buffer.append(")");
return buffer.toString();
}
}