org.daisy.dotify.common.io.FileIO Maven / Gradle / Ivy
package org.daisy.dotify.common.io;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Provides file IO tools.
*
* @author Joel Håkansson
*/
public class FileIO {
private static final Logger logger = Logger.getLogger(FileIO.class.getCanonicalName());
private FileIO() {
}
/**
* Copies an input stream to an output stream. In Java 9 or later, use
* is.transferTo(OutputStream).
*
* @param is the input stream
* @param os the output stream
* @throws IOException if IO fails
*/
//TODO: @deprecated use is.transferTo(OutputStream) (since Java 9)
//TODO: @Deprecated
public static void copy(InputStream is, OutputStream os) throws IOException {
try (
InputStream bis = new BufferedInputStream(is);
OutputStream bos = new BufferedOutputStream(os);
) {
int b;
while ((b = bis.read()) != -1) {
bos.write(b);
}
bos.flush();
}
}
/**
* Creates a temp file.
*
* @return returns a the created file
* @throws IOException if IO fails
*/
public static File createTempFile() throws IOException {
File ret = File.createTempFile("temp", null, null);
ret.deleteOnExit();
return ret;
}
/**
* Creates a temp folder.
*
* @return returns the created folder
* @throws IOException if IO fails
*/
public static File createTempDir() throws IOException {
File temp = File.createTempFile("temp", Long.toString(System.nanoTime()));
if (!temp.delete()) {
temp.deleteOnExit();
}
File tempDir = temp.getParentFile();
File f;
int i = 0;
do {
f = new File(tempDir, Long.toString(System.nanoTime()));
Logger.getLogger(FileIO.class.getCanonicalName()).fine("Attempt to create dir: " + f);
i++;
} while (!f.mkdir() && i < 20);
if (!f.isDirectory()) {
throw new IOException("Failed to create temp dir.");
}
Logger.getLogger(FileIO.class.getCanonicalName()).info("Temp dir created: " + f);
return f;
}
/**
* Copies a folder recursively.
*
* @param f the source folder
* @param out the destination folder
*/
public static void copyRecursive(File f, File out) {
if (f.isDirectory()) {
out.mkdirs();
for (File f1 : f.listFiles()) {
copyRecursive(f1, new File(out, f1.getName()));
}
} else {
try {
Files.copy(f.toPath(), out.toPath(), StandardCopyOption.REPLACE_EXISTING);
} catch (IOException e) {
logger.throwing(FileIO.class.getCanonicalName(), "copyRecursive", e);
}
}
}
/**
* Deletes a folder recursively.
*
* @param f the folder to delete
*/
public static void deleteRecursive(File f) {
if (f.isDirectory()) {
for (File f1 : f.listFiles()) {
deleteRecursive(f1);
}
}
if (!f.delete()) {
f.deleteOnExit();
}
}
/**
* Compares the input streams binary.
*
* @param f1 the first input stream
* @param f2 the second input stream
* @return returns -1 if the streams are equal, byte position where first
* difference occurred otherwise
* @throws IOException if IO fails
*/
public static long diff(InputStream f1, InputStream f2) throws IOException {
try (
InputStream bf1 = new BufferedInputStream(f1);
InputStream bf2 = new BufferedInputStream(f2)
) {
int b1;
int b2;
long pos = 0;
while ((b1 = bf1.read()) != -1 & b1 == (b2 = bf2.read())) {
pos++;
// continue
}
if (b1 != -1 || b2 != -1) {
return pos;
}
return -1;
}
}
/**
* Lists files in the specified folder and sub folders having the specified extension.
* For non-recursive file listing, use: dir.listFiles((parent, name)->name.endsWith(ext));
*
* @param dir the folder to start search
* @param ext the file extensions to find
* @return returns a list of files
*/
public static Collection listFilesRecursive(File dir, String ext) {
List files = new ArrayList<>();
listFilesRecursive(files, dir, pathname -> pathname.isDirectory() || pathname.getName().endsWith(ext));
return files;
}
private static void listFilesRecursive(List files, File dir, FileFilter ff) {
File[] listFiles = dir.listFiles(ff);
if (listFiles == null) {
return;
}
for (File f : listFiles) {
if (f.isDirectory()) {
if (logger.isLoggable(Level.FINE)) {
logger.fine("Scanning dir " + f);
}
listFilesRecursive(files, f, ff);
} else if (f.isFile()) {
if (logger.isLoggable(Level.FINE)) {
logger.fine("Adding file: " + f);
}
files.add(f);
} else {
// ignore
}
}
}
/**
* Converts an array of File objects into URL's.
*
* @param files the files to convert
* @return returns an array of URL's
*/
public static URL[] toURL(File[] files) {
List urls = new ArrayList<>();
if (files != null && files.length > 0) {
for (File f : files) {
try {
urls.add(f.toURI().toURL());
} catch (MalformedURLException e) {
logger.warning("Failed to convert " + f + " into an URL.");
}
}
}
return urls.toArray(new URL[]{});
}
}