io.microsphere.io.FileUtils Maven / Gradle / Ivy
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/**
*
*/
package io.microsphere.io;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import static io.microsphere.constants.FileConstants.FILE_EXTENSION_CHAR;
import static io.microsphere.constants.SeparatorConstants.FILE_SEPARATOR;
import static io.microsphere.net.URLUtils.normalizePath;
import static io.microsphere.util.StringUtils.replace;
import static io.microsphere.util.SystemUtils.IS_OS_WINDOWS;
/**
* {@link File} Utility
*
* @author Mercy
* @version 1.0.0
* @see FileUtils
* @since 1.0.0
*/
public abstract class FileUtils {
/**
* Resolve Relative Path
*
* @param parentDirectory Parent Directory
* @param targetFile Target File
* @return If targetFile is a sub-file of parentDirectory , resolve relative path, or
* null
* @since 1.0.0
*/
public static String resolveRelativePath(File parentDirectory, File targetFile) {
String parentDirectoryPath = parentDirectory.getAbsolutePath();
String targetFilePath = targetFile.getAbsolutePath();
if (!targetFilePath.contains(parentDirectoryPath)) {
return null;
}
return normalizePath(replace(targetFilePath, parentDirectoryPath, FILE_SEPARATOR));
}
/**
* Get File Extension
*
* @param fileName the name of {@link File}
* @return the file extension if found
*/
public static String getFileExtension(String fileName) {
if (fileName == null) {
return null;
}
int index = fileName.lastIndexOf(FILE_EXTENSION_CHAR);
return index > -1 ? fileName.substring(index + 1) : null;
}
/**
* Deletes a directory recursively.
*
* @param directory directory to delete
* @throws IOException in case deletion is unsuccessful
*/
public static void deleteDirectory(File directory) throws IOException {
if (!directory.exists()) {
return;
}
if (!isSymlink(directory)) {
cleanDirectory(directory);
}
if (!directory.delete()) {
String message =
"Unable to delete directory " + directory + ".";
throw new IOException(message);
}
}
/**
* Cleans a directory without deleting it.
*
* @param directory directory to clean
* @throws IOException in case cleaning is unsuccessful
*/
public static void cleanDirectory(File directory) throws IOException {
if (!directory.exists()) {
String message = directory + " does not exist";
throw new IllegalArgumentException(message);
}
if (!directory.isDirectory()) {
String message = directory + " is not a directory";
throw new IllegalArgumentException(message);
}
File[] files = directory.listFiles();
if (files == null) { // null if security restricted
throw new IOException("Failed to list contents of " + directory);
}
IOException exception = null;
for (File file : files) {
try {
forceDelete(file);
} catch (IOException ioe) {
exception = ioe;
}
}
if (null != exception) {
throw exception;
}
}
/**
* Deletes a file. If file is a directory, delete it and all sub-directories.
*
* The difference between File.delete() and this method are:
*
* - A directory to be deleted does not have to be empty.
* - You get exceptions when a file or directory cannot be deleted.
* (java.io.File methods returns a boolean)
*
*
* @param file file or directory to delete, must not be {@code null}
* @throws NullPointerException if the directory is {@code null}
* @throws FileNotFoundException if the file was not found
* @throws IOException in case deletion is unsuccessful
*/
public static void forceDelete(File file) throws IOException {
if (file.isDirectory()) {
deleteDirectory(file);
} else {
boolean filePresent = file.exists();
if (!file.delete()) {
if (!filePresent) {
throw new FileNotFoundException("File does not exist: " + file);
}
String message =
"Unable to delete file: " + file;
throw new IOException(message);
}
}
}
/**
* Schedules a file to be deleted when JVM exits.
* If file is directory delete it and all sub-directories.
*
* @param file file or directory to delete, must not be {@code null}
* @throws NullPointerException if the file is {@code null}
* @throws IOException in case deletion is unsuccessful
*/
public static void forceDeleteOnExit(File file) throws IOException {
if (file.isDirectory()) {
deleteDirectoryOnExit(file);
} else {
file.deleteOnExit();
}
}
/**
* Schedules a directory recursively for deletion on JVM exit.
*
* @param directory directory to delete, must not be {@code null}
* @throws NullPointerException if the directory is {@code null}
* @throws IOException in case deletion is unsuccessful
*/
private static void deleteDirectoryOnExit(File directory) throws IOException {
if (!directory.exists()) {
return;
}
directory.deleteOnExit();
if (!isSymlink(directory)) {
cleanDirectoryOnExit(directory);
}
}
/**
* Cleans a directory without deleting it.
*
* @param directory directory to clean, must not be {@code null}
* @throws NullPointerException if the directory is {@code null}
* @throws IOException in case cleaning is unsuccessful
*/
private static void cleanDirectoryOnExit(File directory) throws IOException {
if (!directory.exists()) {
String message = directory + " does not exist";
throw new IllegalArgumentException(message);
}
if (!directory.isDirectory()) {
String message = directory + " is not a directory";
throw new IllegalArgumentException(message);
}
File[] files = directory.listFiles();
if (files == null) { // null if security restricted
throw new IOException("Failed to list contents of " + directory);
}
IOException exception = null;
for (File file : files) {
try {
forceDeleteOnExit(file);
} catch (IOException ioe) {
exception = ioe;
}
}
if (null != exception) {
throw exception;
}
}
public static boolean isSymlink(File file) throws IOException {
if (file == null) {
throw new NullPointerException("File must not be null");
}
if (IS_OS_WINDOWS) {
return false;
}
File fileInCanonicalDir = null;
if (file.getParent() == null) {
fileInCanonicalDir = file;
} else {
File canonicalDir = file.getParentFile().getCanonicalFile();
fileInCanonicalDir = new File(canonicalDir, file.getName());
}
if (fileInCanonicalDir.getCanonicalFile().equals(fileInCanonicalDir.getAbsoluteFile())) {
return false;
} else {
return true;
}
}
}