org.apache.wicket.util.file.Files Maven / Gradle / Ivy
/*
* 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.wicket.util.file;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import org.apache.wicket.util.encoding.UrlDecoder;
import org.apache.wicket.util.io.IOUtils;
import org.apache.wicket.util.io.Streams;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.string.Strings;
import org.apache.wicket.util.time.Time;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* File utility methods.
*
* @author Jonathan Locke
*/
public class Files
{
private static final Logger logger = LoggerFactory.getLogger(Files.class);
// protocols for urls
private static final String URL_FILE_PREFIX = "file:";
private static final String URL_LOCAL_JAR_FILE_PREFIX = "jar:file:";
// characters not allowed in filenames
private static final String FILENAME_FORBIDDEN_CHARACTERS = "\"*/:<>?\\|,";
/**
* Private constructor to prevent instantiation.
*/
private Files()
{
}
/**
* Strips off the given extension (probably returned from Files.extension()) from the path,
* yielding a base pathname.
*
* @param path
* The path, possibly with an extension to strip
* @param extension
* The extension to strip, or null if no extension exists
* @return The path without any extension
*/
public static String basePath(final String path, final String extension)
{
if (extension != null)
{
return path.substring(0, path.length() - extension.length() - 1);
}
return path;
}
/**
* Gets extension from path
*
* @param path
* The path
* @return The extension, like "bmp" or "html", or null if none can be found
*/
public static String extension(final String path)
{
if (path.indexOf('.') != -1)
{
return Strings.lastPathComponent(path, '.');
}
return null;
}
/**
* Gets filename from path
*
* @param path
* The path
* @return The filename
*/
public static String filename(final String path)
{
return Strings.lastPathComponent(path.replace('/', java.io.File.separatorChar),
java.io.File.separatorChar);
}
/**
* Deletes a normal file.
*
* If the file cannot be deleted for any reason then at most 50 retries are attempted with delay
* of 100ms at each 10th attempt.
*
* @param file
* the file to delete
* @return {@code true} if file was deleted, {@code false} if the file don't exist, is a folder
* or cannot be removed for some reason
*/
public static boolean remove(final java.io.File file)
{
if (file != null && file.isFile())
{
for (int j = 0; j < 5; ++j)
{
for (int i = 0; i < 10; ++i)
{
if (file.delete())
{
return true;
}
try
{
Thread.sleep(100);
}
catch (InterruptedException ix)
{
Thread.currentThread().interrupt();
}
}
}
}
return false;
}
/**
* Deletes a folder by recursively removing the files and folders inside it. Delegates the work
* to {@link #remove(File)} for plain files.
*
* @param folder
* the folder to delete
* @return {@code true} if the folder is deleted successfully.
*/
public static boolean removeFolder(final File folder)
{
if (folder == null)
{
return false;
}
if (folder.isDirectory())
{
File[] files = folder.listFiles();
if (files != null)
{
for (File file : files)
{
if (file.isDirectory())
{
removeFolder(file);
}
else
{
remove(file);
}
}
}
}
// delete the empty folder
return folder.delete();
}
/**
* Schedules a file for removal asynchronously.
*
* @param file
* the file to be removed
* @param fileCleaner
* the file cleaner that will be used to remove the file
* @return {@code false} if the {@code file} is null or a folder, {@code true} -
* otherwise (i.e. if it is scheduled)
*/
public static boolean removeAsync(final File file, final IFileCleaner fileCleaner)
{
if (file == null || file.isDirectory())
{
return false;
}
Args.notNull(fileCleaner, "fileCleaner");
fileCleaner.track(file, new Object());
return true;
}
/**
* Schedules a folder and all files inside it for asynchronous removal.
*
* @param folder
* the folder to be removed
* @param fileCleaner
* the file cleaner that will be used to remove the file
* @return {@code false} if the {@code folder} is null or a normal file, {@code true} -
* otherwise (i.e. if it is scheduled)
*/
public static boolean removeFolderAsync(final File folder, final IFileCleaner fileCleaner)
{
if (folder == null || folder.isFile())
{
return false;
}
Args.notNull(fileCleaner, "fileCleaner");
fileCleaner.track(folder, new Object(), new FolderDeleteStrategy());
return true;
}
/**
* Writes the given input stream to the given file
*
* @param file
* The file to write to
* @param input
* The input
* @return Number of bytes written
* @throws IOException
*/
public static int writeTo(final java.io.File file, final InputStream input)
throws IOException
{
return writeTo(file, input, 4096);
}
/**
* read binary file fully
*
* @param file
* file to read
* @return byte array representing the content of the file
* @throws IOException
* is something went wrong
*/
public static byte[] readBytes(final File file) throws IOException
{
FileInputStream stream = new FileInputStream(file);
try
{
return IOUtils.toByteArray(stream);
}
finally
{
stream.close();
}
}
/**
* Writes the given input stream to the given file
*
* @param file
* The file to write to
* @param input
* The input
* @param bufSize
* The memory buffer size. 4096 is a good value.
* @return Number of bytes written
* @throws IOException
*/
public static int writeTo(final java.io.File file, final InputStream input,
final int bufSize) throws IOException
{
final FileOutputStream out = new FileOutputStream(file);
try
{
return Streams.copy(input, out, bufSize);
}
finally
{
out.close();
}
}
/**
*
* Replaces commonly unsupported characters with '_'
*
*
* @param filename
* to be cleaned
* @return cleaned filename
*/
public static String cleanupFilename(final String filename)
{
String name = filename;
for (int i = 0; i < FILENAME_FORBIDDEN_CHARACTERS.length(); i++)
{
name = name.replace(FILENAME_FORBIDDEN_CHARACTERS.charAt(i), '_');
}
return name;
}
/**
* make a copy of a file
*
* @param sourceFile
* source file that needs to be cloned
* @param targetFile
* target file that should be a duplicate of source file
* @throws IOException
* if something went wrong
*/
public static void copy(final File sourceFile, final File targetFile) throws IOException
{
BufferedInputStream in = null;
BufferedOutputStream out = null;
try
{
in = new BufferedInputStream(new FileInputStream(sourceFile));
out = new BufferedOutputStream(new FileOutputStream(targetFile));
IOUtils.copy(in, out);
}
finally
{
try
{
IOUtils.close(in);
}
finally
{
IOUtils.close(out);
}
}
}
/**
* for urls that point to local files (e.g. 'file:' or 'jar:file:') this methods returns a
* reference to the local file
*
* @param url
* url of the resource
*
* @return reference to a local file if url contains one, null otherwise
*
* @see #getLocalFileFromUrl(String)
*/
public static File getLocalFileFromUrl(URL url)
{
final URL location = Args.notNull(url, "url");
return getLocalFileFromUrl(UrlDecoder.PATH_INSTANCE.decode(location.toExternalForm(), "UTF-8"));
}
/**
* for urls that point to local files (e.g. 'file:' or 'jar:file:') this methods returns a
* reference to the local file
*
* @param url
* url of the resource
*
* @return reference to a local file if url contains one, null otherwise
*
* @see #getLocalFileFromUrl(URL)
*/
public static File getLocalFileFromUrl(String url)
{
final String location = Args.notNull(url, "url");
// check for 'file:'
if (location.startsWith(URL_FILE_PREFIX))
{
return new File(location.substring(URL_FILE_PREFIX.length()));
}
// check for 'jar:file:'
else if (location.startsWith(URL_LOCAL_JAR_FILE_PREFIX))
{
final String path = location.substring(URL_LOCAL_JAR_FILE_PREFIX.length());
final int resourceAt = path.indexOf('!');
// for jar:file: the '!' is mandatory
if (resourceAt == -1)
{
return null;
}
return new File(path.substring(0, resourceAt));
}
else
{
return null;
}
}
/**
* get last modification timestamp for file
*
* @param file
*
* @return timestamp
*/
public static Time getLastModified(File file)
{
// get file modification timestamp
long millis = file.lastModified();
// zero indicates the timestamp could not be retrieved or the file does not exist
if (millis == 0)
{
return null;
}
// last file modification timestamp
return Time.millis(millis);
}
/**
* Utility method for creating a directory. If the creation didn't succeed for some reason then
* at most 50 attempts are made with delay of 100ms at every 10th attempt.
*
* @param folder
* the folder to create
* @return {@code true} if the creation is successful, {@code false} - otherwise
*/
public static boolean mkdirs(File folder)
{
// for some reason, simple file.mkdirs sometimes fails under heavy load
for (int j = 0; j < 5; ++j)
{
for (int i = 0; i < 10; ++i)
{
if (folder.mkdirs())
{
return true;
}
}
try
{
Thread.sleep(100);
if (folder.exists()) return true;
}
catch (InterruptedException ix)
{
Thread.currentThread().interrupt();
}
}
logger.error("Failed to create directory: " + folder);
return false;
}
}