* Facilities are provided in the following areas: *
* Origin of code: Excalibur, Alexandria, Commons-Utils
*
* @author Kevin A. Burton
* @author Scott Sanders
* @author Daniel Rall
* @author Christoph.Reck
* @author Peter Donald
* @author Jeff Turner
* @author Matthew Hawthorne
* @author Jeremias Maerki
* @author Stephen Colebourne
* @author Ian Springer
* @author Chris Eldredge
* @author Jim Harrington
* @author Niall Pemberton
* @author Sandy McArthur
* @version $Id: FileUtils.java 610810 2008-01-10 15:04:49Z niallp $
*/
@VisibleForTesting
public class FileUtils {
/**
* Instances should NOT be constructed in standard programming.
*/
public FileUtils() {
super();
}
/**
* The number of bytes in a kilobyte.
*/
public static final long ONE_KB = 1024;
/**
* The number of bytes in a megabyte.
*/
public static final long ONE_MB = ONE_KB * ONE_KB;
/**
* The number of bytes in a gigabyte.
*/
public static final long ONE_GB = ONE_KB * ONE_MB;
/**
* An empty array of type File.
*/
public static final File[] EMPTY_FILE_ARRAY = new File[0];
//-----------------------------------------------------------------------
/**
* Opens a {@link FileInputStream} for the specified file, providing better
* error messages than simply calling new FileInputStream(file).
*
* At the end of the method either the stream will be successfully opened, * or an exception will have been thrown. *
* An exception is thrown if the file does not exist.
* An exception is thrown if the file object exists but is a directory.
* An exception is thrown if the file exists but cannot be read.
*
* @param file the file to open for input, must not be null
* @return a new {@link FileInputStream} for the specified file
* @throws FileNotFoundException if the file does not exist
* @throws IOException if the file object is a directory
* @throws IOException if the file cannot be read
* @since Commons IO 1.3
*/
public static FileInputStream openInputStream(File file) throws IOException {
if (file.exists()) {
if (file.isDirectory()) {
throw new IOException("File '" + file + "' exists but is a directory");
}
if (file.canRead() == false) {
throw new IOException("File '" + file + "' cannot be read");
}
} else {
throw new FileNotFoundException("File '" + file + "' does not exist");
}
return new FileInputStream(file);
}
//-----------------------------------------------------------------------
/**
* Opens a {@link FileOutputStream} for the specified file, checking and
* creating the parent directory if it does not exist.
*
* At the end of the method either the stream will be successfully opened, * or an exception will have been thrown. *
* The parent directory will be created if it does not exist.
* The file will be created if it does not exist.
* An exception is thrown if the file object exists but is a directory.
* An exception is thrown if the file exists but cannot be written to.
* An exception is thrown if the parent directory cannot be created.
*
* @param file the file to open for output, must not be null
* @return a new {@link FileOutputStream} for the specified file
* @throws IOException if the file object is a directory
* @throws IOException if the file cannot be written to
* @throws IOException if a parent directory needs creating but that fails
* @since Commons IO 1.3
*/
public static FileOutputStream openOutputStream(File file) throws IOException {
if (file.exists()) {
if (file.isDirectory()) {
throw new IOException("File '" + file + "' exists but is a directory");
}
if (file.canWrite() == false) {
throw new IOException("File '" + file + "' cannot be written to");
}
} else {
File parent = file.getParentFile();
if (parent != null && parent.exists() == false) {
if (parent.mkdirs() == false) {
throw new IOException("File '" + file + "' could not be created");
}
}
}
return new FileOutputStream(file);
}
//-----------------------------------------------------------------------
/**
* Returns a human-readable version of the file size, where the input
* represents a specific number of bytes.
*
* @param size the number of bytes
* @return a human-readable display value (includes units)
*/
public static String byteCountToDisplaySize(long size) {
String displaySize;
if (size / ONE_GB > 0) {
displaySize = String.valueOf(size / ONE_GB) + " GB";
} else if (size / ONE_MB > 0) {
displaySize = String.valueOf(size / ONE_MB) + " MB";
} else if (size / ONE_KB > 0) {
displaySize = String.valueOf(size / ONE_KB) + " KB";
} else {
displaySize = String.valueOf(size) + " bytes";
}
return displaySize;
}
//-----------------------------------------------------------------------
/**
* Implements the same behaviour as the "touch" utility on Unix. It creates
* a new file with size 0 or, if the file exists already, it is opened and
* closed without modifying it, but updating the file date and time.
*
* NOTE: As from v1.3, this method throws an IOException if the last
* modified date of the file cannot be set. Also, as from v1.3 this method
* creates parent directories if they do not exist.
*
* @param file the File to touch
* @throws IOException If an I/O problem occurs
*/
public static void touch(File file) throws IOException {
if (!file.exists()) {
OutputStream out = openOutputStream(file);
IOUtils.closeQuietly(out);
}
boolean success = file.setLastModified(System.currentTimeMillis());
if (!success) {
throw new IOException("Unable to set the last modification time for " + file);
}
}
//-----------------------------------------------------------------------
/**
* Converts a Collection containing java.io.File instanced into array
* representation. This is to account for the difference between
* File.listFiles() and FileUtils.listFiles().
*
* @param files a Collection containing java.io.File instances
* @return an array of java.io.File
*/
public static File[] convertFileCollectionToFileArray(Collection
* If your search should recurse into subdirectories you can pass in
* an IOFileFilter for directories. You don't need to bind a
* DirectoryFileFilter (via logical AND) to this filter. This method does
* that for you.
*
* An example: If you want to search through all directories called
* "temp" you pass in
* Another common usage of this method is find files in a directory
* tree but ignoring the directories generated CVS. You can simply pass
* in
* All files found are filtered by an IOFileFilter. This method is
* based on {@link #listFiles(File, IOFileFilter, IOFileFilter)}.
*
* @param directory the directory to search in
* @param fileFilter filter to apply when finding files.
* @param dirFilter optional filter to apply when finding subdirectories.
* If this parameter is
* This method checks to see if the two files are different lengths
* or if they point to the same file, before resorting to byte-by-byte
* comparison of the contents.
*
* Code origin: Avalon
*
* @param file1 the first file
* @param file2 the second file
* @return true if the content of the files are equal or they both don't
* exist, false otherwise
* @throws IOException in case of an I/O error
*/
public static boolean contentEquals(File file1, File file2) throws IOException {
boolean file1Exists = file1.exists();
if (file1Exists != file2.exists()) {
return false;
}
if (!file1Exists) {
// two not existing files are equal
return true;
}
if (file1.isDirectory() || file2.isDirectory()) {
// don't want to compare directory contents
throw new IOException("Can't compare directories, only files");
}
if (file1.length() != file2.length()) {
// lengths differ, cannot be equal
return false;
}
if (file1.getCanonicalFile().equals(file2.getCanonicalFile())) {
// same file
return true;
}
InputStream input1 = null;
InputStream input2 = null;
try {
input1 = new FileInputStream(file1);
input2 = new FileInputStream(file2);
return IOUtils.contentEquals(input1, input2);
} finally {
IOUtils.closeQuietly(input1);
IOUtils.closeQuietly(input2);
}
}
//-----------------------------------------------------------------------
/**
* Convert from a
* From version 1.1 this method will decode the URL.
* Syntax such as
* Returns an array of the same size as the input.
* If the input is
* This method will decode the URL.
* Syntax such as
* Returns an array of the same size as the input.
*
* @param files the files to convert
* @return an array of URLs matching the input
* @throws IOException if a file cannot be converted
*/
public static URL[] toURLs(File[] files) throws IOException {
URL[] urls = new URL[files.length];
for (int i = 0; i < urls.length; i++) {
urls[i] = files[i].toURI().toURL();
}
return urls;
}
//-----------------------------------------------------------------------
/**
* Copies a file to a directory preserving the file date.
*
* This method copies the contents of the specified source file
* to a file of the same name in the specified destination directory.
* The destination directory is created if it does not exist.
* If the destination file exists, then this method will overwrite it.
*
* @param srcFile an existing file to copy, must not be
* This method copies the contents of the specified source file
* to a file of the same name in the specified destination directory.
* The destination directory is created if it does not exist.
* If the destination file exists, then this method will overwrite it.
*
* @param srcFile an existing file to copy, must not be
* This method copies the contents of the specified source file to the
* specified destination file. The directory holding the destination file is
* created if it does not exist. If the destination file exists, then this
* method will overwrite it.
*
* @param srcFile an existing file to copy, must not be
* This method copies the contents of the specified source file
* to the specified destination file.
* The directory holding the destination file is created if it does not exist.
* If the destination file exists, then this method will overwrite it.
*
* @param srcFile an existing file to copy, must not be
* This method copies the source directory and all its contents to a
* directory of the same name in the specified destination directory.
*
* The destination directory is created if it does not exist.
* If the destination directory did exist, then this method merges
* the source with the destination, with the source taking precedence.
*
* @param srcDir an existing directory to copy, must not be
* This method copies the specified directory and all its child
* directories and files to the specified destination.
* The destination is the new location and name of the directory.
*
* The destination directory is created if it does not exist.
* If the destination directory did exist, then this method merges
* the source with the destination, with the source taking precedence.
*
* @param srcDir an existing directory to copy, must not be
* This method copies the contents of the specified source directory
* to within the specified destination directory.
*
* The destination directory is created if it does not exist.
* If the destination directory did exist, then this method merges
* the source with the destination, with the source taking precedence.
*
* @param srcDir an existing directory to copy, must not be
* This method copies the contents of the specified source directory
* to within the specified destination directory.
*
* The destination directory is created if it does not exist.
* If the destination directory did exist, then this method merges
* the source with the destination, with the source taking precedence.
*
*
* This method copies the contents of the specified source directory
* to within the specified destination directory.
*
* The destination directory is created if it does not exist.
* If the destination directory did exist, then this method merges
* the source with the destination, with the source taking precedence.
*
*
* The difference between File.delete() and this method are:
*
* This method repeatedly tests {@link File#exists()} until it returns
* true up to the maximum time specified in seconds.
*
* @param file the file to check, must not be
* This method opens an
* The recommended usage pattern is:
*
* If an exception occurs during the creation of the iterator, the
* underlying stream is closed.
*
* @param file the file to open for input, must not be
* NOTE: As from v1.3, the parent directories of the file will be created
* if they do not exist.
*
* @param file the file to write to
* @param data the content to write to the file
* @throws IOException in case of an I/O error
* @since Commons IO 1.1
*/
public static void writeByteArrayToFile(File file, byte[] data) throws IOException {
OutputStream out = null;
try {
out = openOutputStream(file);
out.write(data);
} finally {
IOUtils.closeQuietly(out);
}
}
/**
* Writes the
* NOTE: As from v1.3, the parent directories of the file will be created
* if they do not exist.
*
* @param file the file to write to
* @param encoding the encoding to use, FileFilterUtils.NameFileFilter("temp")
* FileFilterUtils.makeCVSAware(null).
*
* @param directory the directory to search in
* @param fileFilter filter to apply when finding files.
* @param dirFilter optional filter to apply when finding subdirectories.
* If this parameter is null, subdirectories will not be included in the
* search. Use TrueFileFilter.INSTANCE to match all directories.
* @return an collection of java.io.File with the matching files
* @see org.apache.commons.io.filefilter.FileFilterUtils
* @see org.apache.commons.io.filefilter.NameFileFilter
*/
public static Collectionnull, subdirectories will not be included in the
* search. Use TrueFileFilter.INSTANCE to match all directories.
* @return an iterator of java.io.File for the matching files
* @see org.apache.commons.io.filefilter.FileFilterUtils
* @see org.apache.commons.io.filefilter.NameFileFilter
* @since Commons IO 1.2
*/
public static Iteratornull, all files are returned.
* @param recursive if true all subdirectories are searched as well
* @return an collection of java.io.File with the matching files
*/
public static Collectionnull, all files are returned.
* @param recursive if true all subdirectories are searched as well
* @return an iterator of java.io.File with the matching files
* @since Commons IO 1.2
*/
public static IteratorURL to a File.
* file:///my%20docs/file.txt will be
* correctly decoded to /my docs/file.txt.
*
* @param url the file URL to convert, null returns null
* @return the equivalent File object, or null
* if the URL's protocol is not file
* @throws IllegalArgumentException if the file is incorrectly encoded
*/
public static File toFile(URL url) {
if (url == null || !url.getProtocol().equals("file")) {
return null;
} else {
String filename = url.getFile().replace('/', File.separatorChar);
int pos =0;
while ((pos = filename.indexOf('%', pos)) >= 0) {
if (pos + 2 < filename.length()) {
String hexStr = filename.substring(pos + 1, pos + 3);
char ch = (char) Integer.parseInt(hexStr, 16);
filename = filename.substring(0, pos) + ch + filename.substring(pos + 3);
}
}
return new File(filename);
}
}
/**
* Converts each of an array of URL to a File.
* null, an empty array is returned.
* If the input contains null, the output array contains null at the same
* index.
* file:///my%20docs/file.txt will be
* correctly decoded to /my docs/file.txt.
*
* @param urls the file URLs to convert, null returns empty array
* @return a non-null array of Files matching the input, with a null item
* if there was a null at that index in the input array
* @throws IllegalArgumentException if any file is not a URL file
* @throws IllegalArgumentException if any file is incorrectly encoded
* @since Commons IO 1.1
*/
public static File[] toFiles(URL[] urls) {
if (urls == null || urls.length == 0) {
return EMPTY_FILE_ARRAY;
}
File[] files = new File[urls.length];
for (int i = 0; i < urls.length; i++) {
URL url = urls[i];
if (url != null) {
if (url.getProtocol().equals("file") == false) {
throw new IllegalArgumentException(
"URL could not be converted to a File: " + url);
}
files[i] = toFile(url);
}
}
return files;
}
/**
* Converts each of an array of File to a URL.
* null
* @param destDir the directory to place the copy in, must not be null
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @see #copyFile(File, File, boolean)
*/
public static void copyFileToDirectory(File srcFile, File destDir) throws IOException {
copyFileToDirectory(srcFile, destDir, true);
}
/**
* Copies a file to a directory optionally preserving the file date.
* null
* @param destDir the directory to place the copy in, must not be null
* @param preserveFileDate true if the file date of the copy
* should be the same as the original
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @see #copyFile(File, File, boolean)
* @since Commons IO 1.3
*/
public static void copyFileToDirectory(File srcFile, File destDir, boolean preserveFileDate) throws IOException {
if (destDir == null) {
throw new NullPointerException("Destination must not be null");
}
if (destDir.exists() && destDir.isDirectory() == false) {
throw new IllegalArgumentException("Destination '" + destDir + "' is not a directory");
}
copyFile(srcFile, new File(destDir, srcFile.getName()), preserveFileDate);
}
/**
* Copies a file to a new location preserving the file date.
* null
* @param destFile the new file, must not be null
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @see #copyFileToDirectory(File, File)
*/
public static void copyFile(File srcFile, File destFile) throws IOException {
copyFile(srcFile, destFile, true);
}
/**
* Copies a file to a new location.
* null
* @param destFile the new file, must not be null
* @param preserveFileDate true if the file date of the copy
* should be the same as the original
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @see #copyFileToDirectory(File, File, boolean)
*/
public static void copyFile(File srcFile, File destFile,
boolean preserveFileDate) throws IOException {
if (srcFile == null) {
throw new NullPointerException("Source must not be null");
}
if (destFile == null) {
throw new NullPointerException("Destination must not be null");
}
if (srcFile.exists() == false) {
throw new FileNotFoundException("Source '" + srcFile + "' does not exist");
}
if (srcFile.isDirectory()) {
throw new IOException("Source '" + srcFile + "' exists but is a directory");
}
if (srcFile.getCanonicalPath().equals(destFile.getCanonicalPath())) {
throw new IOException("Source '" + srcFile + "' and destination '" + destFile + "' are the same");
}
if (destFile.getParentFile() != null && destFile.getParentFile().exists() == false) {
if (destFile.getParentFile().mkdirs() == false) {
throw new IOException("Destination '" + destFile + "' directory cannot be created");
}
}
if (destFile.exists() && destFile.canWrite() == false) {
throw new IOException("Destination '" + destFile + "' exists but is read-only");
}
doCopyFile(srcFile, destFile, preserveFileDate);
}
/**
* Internal copy file method.
*
* @param srcFile the validated source file, must not be null
* @param destFile the validated destination file, must not be null
* @param preserveFileDate whether to preserve the file date
* @throws IOException if an error occurs
*/
private static void doCopyFile(File srcFile, File destFile, boolean preserveFileDate) throws IOException {
if (destFile.exists() && destFile.isDirectory()) {
throw new IOException("Destination '" + destFile + "' exists but is a directory");
}
FileInputStream input = new FileInputStream(srcFile);
try {
FileOutputStream output = new FileOutputStream(destFile);
try {
IOUtils.copy(input, output);
} finally {
IOUtils.closeQuietly(output);
}
} finally {
IOUtils.closeQuietly(input);
}
if (srcFile.length() != destFile.length()) {
throw new IOException("Failed to copy full contents from '" +
srcFile + "' to '" + destFile + "'");
}
if (preserveFileDate) {
destFile.setLastModified(srcFile.lastModified());
}
}
//-----------------------------------------------------------------------
/**
* Copies a directory to within another directory preserving the file dates.
* null
* @param destDir the directory to place the copy in, must not be null
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @since Commons IO 1.2
*/
public static void copyDirectoryToDirectory(File srcDir, File destDir) throws IOException {
if (srcDir == null) {
throw new NullPointerException("Source must not be null");
}
if (srcDir.exists() && srcDir.isDirectory() == false) {
throw new IllegalArgumentException("Source '" + destDir + "' is not a directory");
}
if (destDir == null) {
throw new NullPointerException("Destination must not be null");
}
if (destDir.exists() && destDir.isDirectory() == false) {
throw new IllegalArgumentException("Destination '" + destDir + "' is not a directory");
}
copyDirectory(srcDir, new File(destDir, srcDir.getName()), true);
}
/**
* Copies a whole directory to a new location preserving the file dates.
* null
* @param destDir the new directory, must not be null
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @since Commons IO 1.1
*/
@VisibleForTesting
public static void copyDirectory(File srcDir, File destDir) throws IOException {
copyDirectory(srcDir, destDir, true);
}
/**
* Copies a whole directory to a new location.
* null
* @param destDir the new directory, must not be null
* @param preserveFileDate true if the file date of the copy
* should be the same as the original
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @since Commons IO 1.1
*/
public static void copyDirectory(File srcDir, File destDir,
boolean preserveFileDate) throws IOException {
copyDirectory(srcDir, destDir, null, preserveFileDate);
}
/**
* Copies a filtered directory to a new location preserving the file dates.
* Example: Copy directories only
*
* // only copy the directory structure
* FileUtils.copyDirectory(srcDir, destDir, DirectoryFileFilter.DIRECTORY);
*
*
* Example: Copy directories and txt files
*
* // Create a filter for ".txt" files
* IOFileFilter txtSuffixFilter = FileFilterUtils.suffixFileFilter(".txt");
* IOFileFilter txtFiles = FileFilterUtils.andFileFilter(FileFileFilter.FILE, txtSuffixFilter);
*
* // Create a filter for either directories or ".txt" files
* FileFilter filter = FileFilterUtils.orFileFilter(DirectoryFileFilter.DIRECTORY, txtFiles);
*
* // Copy using the filter
* FileUtils.copyDirectory(srcDir, destDir, filter);
*
*
* @param srcDir an existing directory to copy, must not be null
* @param destDir the new directory, must not be null
* @param filter the filter to apply, null means copy all directories and files
* should be the same as the original
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @since Commons IO 1.4
*/
public static void copyDirectory(File srcDir, File destDir,
FileFilter filter) throws IOException {
copyDirectory(srcDir, destDir, filter, true);
}
/**
* Copies a filtered directory to a new location.
* Example: Copy directories only
*
* // only copy the directory structure
* FileUtils.copyDirectory(srcDir, destDir, DirectoryFileFilter.DIRECTORY, false);
*
*
* Example: Copy directories and txt files
*
* // Create a filter for ".txt" files
* IOFileFilter txtSuffixFilter = FileFilterUtils.suffixFileFilter(".txt");
* IOFileFilter txtFiles = FileFilterUtils.andFileFilter(FileFileFilter.FILE, txtSuffixFilter);
*
* // Create a filter for either directories or ".txt" files
* FileFilter filter = FileFilterUtils.orFileFilter(DirectoryFileFilter.DIRECTORY, txtFiles);
*
* // Copy using the filter
* FileUtils.copyDirectory(srcDir, destDir, filter, false);
*
*
* @param srcDir an existing directory to copy, must not be null
* @param destDir the new directory, must not be null
* @param filter the filter to apply, null means copy all directories and files
* @param preserveFileDate true if the file date of the copy
* should be the same as the original
*
* @throws NullPointerException if source or destination is null
* @throws IOException if source or destination is invalid
* @throws IOException if an IO error occurs during copying
* @since Commons IO 1.4
*/
public static void copyDirectory(File srcDir, File destDir,
FileFilter filter, boolean preserveFileDate) throws IOException {
if (srcDir == null) {
throw new NullPointerException("Source must not be null");
}
if (destDir == null) {
throw new NullPointerException("Destination must not be null");
}
if (srcDir.exists() == false) {
throw new FileNotFoundException("Source '" + srcDir + "' does not exist");
}
if (srcDir.isDirectory() == false) {
throw new IOException("Source '" + srcDir + "' exists but is not a directory");
}
if (srcDir.getCanonicalPath().equals(destDir.getCanonicalPath())) {
throw new IOException("Source '" + srcDir + "' and destination '" + destDir + "' are the same");
}
// Cater for destination being directory within the source directory (see IO-141)
Listnull
* @param destDir the validated destination directory, must not be null
* @param filter the filter to apply, null means copy all directories and files
* @param preserveFileDate whether to preserve the file date
* @param exclusionList List of files and directories to exclude from the copy, may be null
* @throws IOException if an error occurs
* @since Commons IO 1.1
*/
private static void doCopyDirectory(File srcDir, File destDir, FileFilter filter,
boolean preserveFileDate, Listsource to a file
* destination. The directories up to destination
* will be created if they don't already exist. destination
* will be overwritten if it already exists.
*
* @param source the URL to copy bytes from, must not be null
* @param destination the non-directory File to write bytes to
* (possibly overwriting), must not be null
* @throws IOException if source URL cannot be opened
* @throws IOException if destination is a directory
* @throws IOException if destination cannot be written
* @throws IOException if destination needs creating but can't be
* @throws IOException if an IO error occurs during copying
*/
public static void copyURLToFile(URL source, File destination) throws IOException {
InputStream input = source.openStream();
try {
FileOutputStream output = openOutputStream(destination);
try {
IOUtils.copy(input, output);
} finally {
IOUtils.closeQuietly(output);
}
} finally {
IOUtils.closeQuietly(input);
}
}
//-----------------------------------------------------------------------
/**
* 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;
}
cleanDirectory(directory);
if (!directory.delete()) {
String message =
"Unable to delete directory " + directory + ".";
throw new IOException(message);
}
}
/**
* Deletes a file, never throwing an exception. If file is a directory, delete it and all sub-directories.
*
*
*
* @param file file or directory to delete, can be null
* @return true if the file or directory was deleted, otherwise
* false
*
* @since Commons IO 1.4
*/
public static boolean deleteQuietly(File file) {
if (file == null) {
return false;
}
try {
if (file.isDirectory()) {
cleanDirectory(file);
}
} catch (Exception e) {
}
try {
return file.delete();
} catch (Exception e) {
return false;
}
}
/**
* 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 (int i = 0; i < files.length; i++) {
File file = files[i];
try {
forceDelete(file);
} catch (IOException ioe) {
exception = ioe;
}
}
if (null != exception) {
throw exception;
}
}
//-----------------------------------------------------------------------
/**
* Waits for NFS to propagate a file creation, imposing a timeout.
* null
* @param seconds the maximum time in seconds to wait
* @return true if file exists
* @throws NullPointerException if the file is null
*/
public static boolean waitFor(File file, int seconds) {
int timeout = 0;
int tick = 0;
while (!file.exists()) {
if (tick++ >= 10) {
tick = 0;
if (timeout++ > seconds) {
return false;
}
}
try {
Thread.sleep(100);
} catch (InterruptedException ignore) {
// ignore exception
} catch (Exception ex) {
break;
}
}
return true;
}
//-----------------------------------------------------------------------
/**
* Reads the contents of a file into a String.
* The file is always closed.
*
* @param file the file to read, must not be null
* @param encoding the encoding to use, null means platform default
* @return the file contents, never null
* @throws IOException in case of an I/O error
* @throws java.io.UnsupportedEncodingException if the encoding is not supported by the VM
*/
public static String readFileToString(File file, String encoding) throws IOException {
InputStream in = null;
try {
in = openInputStream(file);
return IOUtils.toString(in, encoding);
} finally {
IOUtils.closeQuietly(in);
}
}
/**
* Reads the contents of a file into a String using the default encoding for the VM.
* The file is always closed.
*
* @param file the file to read, must not be null
* @return the file contents, never null
* @throws IOException in case of an I/O error
* @since Commons IO 1.3.1
*/
public static String readFileToString(File file) throws IOException {
return readFileToString(file, null);
}
/**
* Reads the contents of a file into a byte array.
* The file is always closed.
*
* @param file the file to read, must not be null
* @return the file contents, never null
* @throws IOException in case of an I/O error
* @since Commons IO 1.1
*/
public static byte[] readFileToByteArray(File file) throws IOException {
InputStream in = null;
try {
in = openInputStream(file);
return IOUtils.toByteArray(in);
} finally {
IOUtils.closeQuietly(in);
}
}
/**
* Reads the contents of a file line by line to a List of Strings.
* The file is always closed.
*
* @param file the file to read, must not be null
* @param encoding the encoding to use, null means platform default
* @return the list of Strings representing each line in the file, never null
* @throws IOException in case of an I/O error
* @throws java.io.UnsupportedEncodingException if the encoding is not supported by the VM
* @since Commons IO 1.1
*/
public static Listnull
* @return the list of Strings representing each line in the file, never null
* @throws IOException in case of an I/O error
* @since Commons IO 1.3
*/
public static ListFile.
* InputStream for the file.
* When you have finished with the iterator you should close the stream
* to free internal resources. This can be done by calling the
* {@link LineIterator#close()} or
* {@link LineIterator#closeQuietly(LineIterator)} method.
*
* LineIterator it = FileUtils.lineIterator(file, "UTF-8");
* try {
* while (it.hasNext()) {
* String line = it.nextLine();
* /// do something with line
* }
* } finally {
* LineIterator.closeQuietly(iterator);
* }
*
* null
* @param encoding the encoding to use, null means platform default
* @return an Iterator of the lines in the file, never null
* @throws IOException in case of an I/O error (file closed)
* @since Commons IO 1.2
*/
public static LineIterator lineIterator(File file, String encoding) throws IOException {
InputStream in = null;
try {
in = openInputStream(file);
return IOUtils.lineIterator(in, encoding);
} catch (IOException ex) {
IOUtils.closeQuietly(in);
throw ex;
} catch (RuntimeException ex) {
IOUtils.closeQuietly(in);
throw ex;
}
}
/**
* Returns an Iterator for the lines in a File using the default encoding for the VM.
*
* @param file the file to open for input, must not be null
* @return an Iterator of the lines in the file, never null
* @throws IOException in case of an I/O error (file closed)
* @since Commons IO 1.3
* @see #lineIterator(File, String)
*/
public static LineIterator lineIterator(File file) throws IOException {
return lineIterator(file, null);
}
//-----------------------------------------------------------------------
/**
* Writes a String to a file creating the file if it does not exist.
*
* NOTE: As from v1.3, the parent directories of the file will be created
* if they do not exist.
*
* @param file the file to write
* @param data the content to write to the file
* @param encoding the encoding to use, null means platform default
* @throws IOException in case of an I/O error
* @throws java.io.UnsupportedEncodingException if the encoding is not supported by the VM
*/
public static void writeStringToFile(File file, String data, String encoding) throws IOException {
OutputStream out = null;
try {
out = openOutputStream(file);
IOUtils.write(data, out, encoding);
} finally {
IOUtils.closeQuietly(out);
}
}
/**
* Writes a String to a file creating the file if it does not exist using the default encoding for the VM.
*
* @param file the file to write
* @param data the content to write to the file
* @throws IOException in case of an I/O error
*/
public static void writeStringToFile(File file, String data) throws IOException {
writeStringToFile(file, data, null);
}
/**
* Writes a byte array to a file creating the file if it does not exist.
* toString() value of each item in a collection to
* the specified File line by line.
* The specified character encoding and the default line ending will be used.
* null means platform default
* @param lines the lines to write, null entries produce blank lines
* @throws IOException in case of an I/O error
* @throws java.io.UnsupportedEncodingException if the encoding is not supported by the VM
* @since Commons IO 1.1
*/
public static void writeLines(File file, String encoding, Collection