com.teamscale.client.FileSystemUtils Maven / Gradle / Ivy
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package com.teamscale.client;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
/**
* File system utilities.
*/
public class FileSystemUtils {
/** Encoding for UTF-8. */
public static final String UTF8_ENCODING = StandardCharsets.UTF_8.name();
/** Unix file path separator */
private static final char UNIX_SEPARATOR = '/';
/**
* Checks if a directory exists. If not it creates the directory and all necessary parent directories.
*
* @throws IOException if directories couldn't be created.
*/
public static void ensureDirectoryExists(File directory) throws IOException {
if (!directory.exists() && !directory.mkdirs()) {
throw new IOException("Couldn't create directory: " + directory);
}
}
/**
* Returns a list of all files and directories contained in the given directory and all subdirectories matching the
* filter provided. The given directory itself is not included in the result.
*
* The file filter may or may not exclude directories.
*
* This method knows nothing about (symbolic and hard) links, so care should be taken when traversing directories
* containing recursive links.
*
* @param directory the directory to start the search from. If this is null or the directory does not exist, an
* empty list is returned.
* @param filter the filter used to determine whether the result should be included. If the filter is null, all
* files and directories are included.
* @return the list of files found (the order is determined by the file system).
*/
public static List listFilesRecursively(File directory, FileFilter filter) {
if (directory == null || !directory.isDirectory()) {
return Collections.emptyList();
}
List result = new ArrayList<>();
listFilesRecursively(directory, result, filter);
return result;
}
/**
* Returns the extension of the file.
*
* @return File extension, i.e. "java" for "FileSystemUtils.java", or
* null, if the file has no extension (i.e. if a filename
* contains no '.'), returns the empty string if the '.' is the filename's last character.
*/
public static String getFileExtension(File file) {
String name = file.getName();
int posLastDot = name.lastIndexOf('.');
if (posLastDot < 0) {
return null;
}
return name.substring(posLastDot + 1);
}
/**
* Finds all files and directories contained in the given directory and all subdirectories matching the filter
* provided and put them into the result collection. The given directory itself is not included in the result.
*
* This method knows nothing about (symbolic and hard) links, so care should be taken when traversing directories
* containing recursive links.
*
* @param directory the directory to start the search from.
* @param result the collection to add to all files found.
* @param filter the filter used to determine whether the result should be included. If the filter is null, all
* files and directories are included.
*/
private static void listFilesRecursively(File directory, Collection result, FileFilter filter) {
File[] files = directory.listFiles();
if (files == null) {
// From the docs of `listFiles`:
// "If this abstract pathname does not denote a directory, then this method returns null."
// Based on this, it seems to be ok to just return here without throwing an exception.
return;
}
for (File file : files) {
if (file.isDirectory()) {
listFilesRecursively(file, result, filter);
}
if (filter == null || filter.accept(file)) {
result.add(file);
}
}
}
/**
* Replace platform dependent separator char with forward slashes to create system-independent paths.
*/
public static String normalizeSeparators(String path) {
return path.replace(File.separatorChar, UNIX_SEPARATOR);
}
/**
* Copy an input stream to an output stream. This does not close the
* streams.
*
* @param input
* input stream
* @param output
* output stream
* @return number of bytes copied
* @throws IOException
* if an IO exception occurs.
*/
public static int copy(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[1024];
int size = 0;
int len;
while ((len = input.read(buffer)) > 0) {
output.write(buffer, 0, len);
size += len;
}
return size;
}
/**
* Returns the name of the given file without extension. Example:
* '/home/joe/data.dat' returns 'data'.
*/
public static String getFilenameWithoutExtension(File file) {
return getFilenameWithoutExtension(file.getName());
}
/**
* Returns the name of the given file without extension. Example: 'data.dat' returns 'data'.
*/
public static String getFilenameWithoutExtension(String fileName) {
return StringUtils.removeLastPart(fileName, '.');
}
}