Java/File Input Output/FileFilter
Версия от 18:01, 31 мая 2010; (обсуждение)
Содержание
- 1 A filesystem filter.
- 2 A prefix based filename filter
- 3 A suffix based file filter.
- 4 Extension Filename Filter
- 5 File filter: retrieve at most predefined number of files which are older than specified data
- 6 Filter by file
- 7 Filter files by name
- 8 Filters files based on the extension (what the filename ends with)
- 9 List files of a certain type
A filesystem filter.
/*
* JCommon : a free general purpose class library for the Java(tm) platform
*
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------------------
* ExtensionFileFilter.java
* ------------------------
* (C) Copyright 2000-2004, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* $Id: FilesystemFilter.java,v 1.6 2008/09/10 09:26:11 mungady Exp $
*
* Changes (from 26-Oct-2001)
* --------------------------
* 01-Jun-2005 : Updated javadoc.
*/
import java.io.File;
import java.io.FilenameFilter;
import javax.swing.filechooser.FileFilter;
/**
* A filesystem filter.
*
* @author David Gilbert
*/
public class FilesystemFilter extends FileFilter implements FilenameFilter {
/** The file extension, which should be accepted. */
private String[] fileext;
/** The filter description. */
private String descr;
/** A flag indicating whether to accept directories. */
private boolean accDirs;
/**
* Creates a new filter.
*
* @param fileext
* the file extension.
* @param descr
* the description.
*/
public FilesystemFilter(final String fileext, final String descr) {
this(fileext, descr, true);
}
/**
* Creates a new filter.
*
* @param fileext
* the file extension.
* @param descr
* the description.
* @param accDirs
* accept directories?
*/
public FilesystemFilter(final String fileext, final String descr, final boolean accDirs) {
this(new String[] { fileext }, descr, accDirs);
}
/**
* Creates a new filter.
*
* @param fileext
* the file extension.
* @param descr
* the description.
* @param accDirs
* accept directories?
* @throws NullPointerException
* if the file extensions are null.
*/
public FilesystemFilter(final String[] fileext, final String descr, final boolean accDirs) {
this.fileext = (String[]) fileext.clone();
this.descr = descr;
this.accDirs = accDirs;
}
/**
* Returns <code>true</code> if the file is accepted, and <code>false</code>
* otherwise.
*
* @param dir
* the directory.
* @param name
* the file name.
* @return A boolean.
*/
public boolean accept(final File dir, final String name) {
final File f = new File(dir, name);
if (f.isDirectory() && acceptsDirectories()) {
return true;
}
for (int i = 0; i < this.fileext.length; i++) {
if (name.endsWith(this.fileext[i])) {
return true;
}
}
return false;
}
/**
* Returns <code>true</code> if the specified file matches the requirements
* of this filter, and <code>false</code> otherwise.
*
* @param dir
* the file or directory.
* @return A boolean.
*/
public boolean accept(final File dir) {
if (dir.isDirectory() && acceptsDirectories()) {
return true;
}
for (int i = 0; i < this.fileext.length; i++) {
if (dir.getName().endsWith(this.fileext[i])) {
return true;
}
}
return false;
}
/**
* Returns the filter description.
*
* @return The filter description.
*/
public String getDescription() {
return this.descr;
}
/**
* Sets the flag that controls whether or not the filter accepts directories.
*
* @param b
* a boolean.
*/
public void acceptDirectories(final boolean b) {
this.accDirs = b;
}
/**
* Returns the flag that indicates whether or not the filter accepts
* directories.
*
* @return A boolean.
*/
public boolean acceptsDirectories() {
return this.accDirs;
}
}
A prefix based filename filter
/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
import java.io.File;
import java.io.FilenameFilter;
/**
* A <em>prefix</em> based filename filter.
*
* @version <tt>$Revision: 1958 $</tt>
* @author
*/
public class FilenamePrefixFilter
implements FilenameFilter
{
/** The prefix which files must have to be accepted. */
protected final String prefix;
/** Flag to signal that we want to ignore the case. */
protected final boolean ignoreCase;
/**
* Construct a <tt>FilenamePrefixFilter</tt>.
*
* @param prefix The prefix which files must have to be accepted.
* @param ignoreCase <tt>True</tt> if the filter should be case-insensitive.
*/
public FilenamePrefixFilter(final String prefix,
final boolean ignoreCase)
{
this.ignoreCase = ignoreCase;
this.prefix = (ignoreCase ? prefix.toLowerCase() : prefix);
}
/**
* Construct a case sensitive <tt>FilenamePrefixFilter</tt>.
*
* @param prefix The prefix which files must have to be accepted.
*/
public FilenamePrefixFilter(final String prefix) {
this(prefix, false);
}
/**
* Check if a file is acceptible.
*
* @param dir The directory the file resides in.
* @param name The name of the file.
* @return <tt>true</tt> if the file is acceptable.
*/
public boolean accept(final File dir, final String name) {
if (ignoreCase) {
return name.toLowerCase().startsWith(prefix);
}
else {
return name.startsWith(prefix);
}
}
}
A suffix based file filter.
/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
import java.io.File;
import java.io.FileFilter;
/**
* A <em>suffix</em> based file filter.
*
* @version <tt>$Revision: 1958 $</tt>
* @author
*/
public class FileSuffixFilter implements FileFilter {
/** A list of suffixes which files must have to be accepted. */
protected final String suffixes[];
/** Flag to signal that we want to ignore the case. */
protected final boolean ignoreCase;
/**
* Construct a <tt>FileSuffixFilter</tt>.
*
* @param suffixes
* A list of suffixes which files mut have to be accepted.
* @param ignoreCase
* <tt>True</tt> if the filter should be case-insensitive.
*/
public FileSuffixFilter(final String suffixes[], final boolean ignoreCase) {
this.ignoreCase = ignoreCase;
if (ignoreCase) {
this.suffixes = new String[suffixes.length];
for (int i = 0; i < suffixes.length; i++) {
this.suffixes[i] = suffixes[i].toLowerCase();
}
} else {
this.suffixes = suffixes;
}
}
/**
* Construct a <tt>FileSuffixFilter</tt>.
*
* @param suffixes
* A list of suffixes which files mut have to be accepted.
*/
public FileSuffixFilter(final String suffixes[]) {
this(suffixes, false);
}
/**
* Construct a <tt>FileSuffixFilter</tt>.
*
* @param suffix
* The suffix which files must have to be accepted.
* @param ignoreCase
* <tt>True</tt> if the filter should be case-insensitive.
*/
public FileSuffixFilter(final String suffix, final boolean ignoreCase) {
this(new String[] { suffix }, ignoreCase);
}
/**
* Construct a case sensitive <tt>FileSuffixFilter</tt>.
*
* @param suffix
* The suffix which files must have to be accepted.
*/
public FileSuffixFilter(final String suffix) {
this(suffix, false);
}
/**
* Check if a file is acceptible.
*
* @param file
* The file to check.
* @return <tt>true</tt> if the file is acceptable.
*/
public boolean accept(final File file) {
boolean success = false;
for (int i = 0; i < suffixes.length && !success; i++) {
if (ignoreCase)
success = file.getName().toLowerCase().endsWith(suffixes[i]);
else
success = file.getName().endsWith(suffixes[i]);
}
return success;
}
}
Extension Filename Filter
/**
* The utillib library.
* More information is available at http://www.jinchess.ru/.
* Copyright (C) 2002 Alexander Maryanovsky.
* All rights reserved.
*
* The utillib library is free software; you can redistribute
* it and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* The utillib library is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with utillib library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import java.io.File;
import java.io.FilenameFilter;
/**
* An implementation of the <code>java.io.FilenameFilter</code> which accepts
* files whose name ends with a certain string. This makes it useful for
* accepting files with a certain extension.
*/
public class ExtensionFilenameFilter implements FilenameFilter{
/**
* The strings with one of which a file"s name must end in order to pass the
* filter.
*/
private final String [] endStrings;
/**
* Creates a new ExtensionFilenameFilter with the given string. Only files
* ending with that string will be accepted. Note that in order to use this
* class to accept only files with a certain extension, you must also provide
* the "." character before the extension. For example, to accept only "txt"
* files, you must pass ".txt".
*/
public ExtensionFilenameFilter(String endString){
this(new String[]{endString});
}
/**
* Creates a new ExtensionFilenameFilter with the given string array. Only
* files ending with one of the strings in the given string array will be
* accepted by the created ExtensionFilenameFilter. Note that in order to use
* this class to accept only files with a certain extension, you must also
* provide the "." character before the extension. For example, to accept
* only "txt" files, you must pass ".txt".
*/
public ExtensionFilenameFilter(String [] endStrings){
this.endStrings = new String[endStrings.length];
for (int i=0;i<endStrings.length;i++){
this.endStrings[i] = endStrings[i];
}
}
/**
* Tests whether the specified file passes the filter. Returns true if the
* file"s name ends with one of the string specified in the constructor.
*/
public boolean accept(File dir, String filename){
for (int i=0;i<endStrings.length;i++){
if (filename.endsWith(endStrings[i]))
return true;
}
return false;
}
}
File filter: retrieve at most predefined number of files which are older than specified data
/*
* Copyright (c) 2003 - 2007 OpenSubsystems s.r.o. Slovak Republic. All rights reserved.
*
* Project: OpenSubsystems
*
* $Id: MaximumFileFilter.java,v 1.4 2007/01/07 06:14:00 bastafidli Exp $
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import java.io.File;
import java.io.FilenameFilter;
import java.util.Date;
/**
* File filter implementation to retrieve at most predefined number of files
* which are older than specified data
*
* @version $Id: MaximumFileFilter.java,v 1.4 2007/01/07 06:14:00 bastafidli Exp $
* @author Miro Halas
* @code.reviewer Miro Halas
* @code.reviewed 1.2 2004/12/18 06:18:25 bastafidli
*/
public class MaximumFileFilter implements FilenameFilter
{
// Attributes ///////////////////////////////////////////////////////////////
/**
* Current number of files in list
*/
protected int m_currentFileCount = 0;
/**
* Maximum number of files in output list
*/
protected int m_iMaximum = 0;
/**
* Last modification time of file have to be before this date, if it is null,
* modification date is not checked
*/
protected Date m_dtOlderThan;
// Constructors /////////////////////////////////////////////////////////////
/**
* Constructor with maximum count of file in the output list.
*
* @param iMax - maximum number of files in output list. If it is 0 length of
* @param dtOlderThen - file last modification time heve to by before this
* date, if it is null modification time is not checked
* output list is unlimited.
*/
public MaximumFileFilter(
int iMax,
Date dtOlderThen
)
{
m_iMaximum = iMax;
m_dtOlderThan = dtOlderThen;
}
/**
* {@inheritDoc}
*/
public boolean accept(
File dir,
String name
)
{
File currentFile = new File(dir, name);
if (currentFile.isDirectory())
{
return false;
}
if ((m_dtOlderThan != null) && (currentFile.lastModified() > m_dtOlderThan.getTime()))
{
return false;
}
if ((m_iMaximum == 0) || (m_currentFileCount <= m_iMaximum))
{
m_currentFileCount++;
}
return m_currentFileCount <= m_iMaximum;
}
}
Filter by file
import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;
public class Main {
public static void main(String[] argv) throws Exception {
File dir = new File("c:\\temp");
FileFilter fileFilter = new FileFilter() {
public boolean accept(File file) {
return file.isDirectory();
}
};
File[] files = dir.listFiles(fileFilter);
}
}
Filter files by name
import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;
public class Main {
public static void main(String[] argv) throws Exception {
File dir = new File("c:\\temp");
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String name) {
return !name.startsWith(".");
}
};
String[] children = dir.list(filter);
}
}
Filters files based on the extension (what the filename ends with)
/****************************************************************
* 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. *
****************************************************************/
import java.io.File;
import java.io.FilenameFilter;
/**
* This filters files based on the extension (what the filename
* ends with). This is used in retrieving all the files of a
* particular type.
*
* <p>Eg., to retrieve and print all <code>*.java</code> files in the current directory:</p>
*
* <pre>
* File dir = new File(".");
* String[] files = dir.list( new ExtensionFileFilter( new String[]{"java"} ) );
* for (int i=0; i<files.length; i++)
* {
* System.out.println(files[i]);
* }
* </pre>
*
* @author Federico Barbieri <fede@apache.org>
* @author Serge Knystautas <sergek@lokitech.ru>
* @author Peter Donald
* @version CVS $Revision: 494012 $ $Date: 2007-01-08 11:23:58 +0100 (Mo, 08 Jan 2007) $
* @since 4.0
*/
public class ExtensionFileFilter
implements FilenameFilter
{
private String[] m_extensions;
public ExtensionFileFilter( final String[] extensions )
{
m_extensions = extensions;
}
public ExtensionFileFilter( final String extension )
{
m_extensions = new String[]{extension};
}
public boolean accept( final File file, final String name )
{
for( int i = 0; i < m_extensions.length; i++ )
{
if( name.endsWith( m_extensions[ i ] ) )
{
return true;
}
}
return false;
}
}
List files of a certain type
import java.io.File;
import java.io.FilenameFilter;
public class Main {
public static void main(String[] args) {
File directory = new File("c:\\");
if (!directory.isDirectory()) {
System.out.println("No directory provided");
return;
}
FilenameFilter filefilter = new FilenameFilter() {
public boolean accept(File dir, String name) {
return name.endsWith(".txt");
}
};
String[] filenames = directory.list(filefilter);
for (String name : filenames) {
System.out.println(name);
}
}
}
