FileUtils

A set of handy file(s) and folder(s) manipulation methods. Most used are:
copy - to copy a file to another folder
stringToFile - to write any text to a file
byteArrayToFile - byte[] usually is JPEG/PNG image representation
makeDirsForFile - ensure all folders of file's path has been created
isReadable - ensures that given file could be read (really has READ access)
isWritable - ensures that given file could be written (really has WRITE access)
deleteFiles - used to empty some folder, usually app's temp files or cache folder

Methods has been optimized for Samsung smartphones (contains a workaround for ENOENT error). Methods named so that you could understand what it does, like getAvailableSpace or mergeFiles etc.

public static void copy(final String src, final String dst) throws IOException
/**
 * Copies an existing file to another destination
 *
 * @param src - String path of a file to copy from
 * @param dst - String path of a file to copy to
 * @throws IOException
 */


public static void copy(final File src, final File dst) throws IOException
/**
 * Copies an existing file to another destination
 *
 * @param src - File to copy from
 * @param dst - File to copy to
 * @throws IOException
 */

public static synchronized void copySynchronized(final File src, final File dst) throws IOException
/**
 * Copies a file to another destination
 *
 * @param src - File to copy from
 * @param dst - File to copy to
 * @throws IOException
 */

public static boolean stringToFile(final String data, final File targetFile)
/**
 * Writes a String to a File (overwrites existing file)
 *
 * @param data       - String to write to a file
 * @param targetFile - target File
 * @return true if all OK or false otherwise
 */

public static boolean stringToFile(final String data, final File targetFile, final boolean doAppend)
/**
 * Writes a String to a File.
 *
 * @param data       - String to write to a file
 * @param targetFile - target File
 * @param doAppend   - append mode on/off
 * @return true if all OK or false otherwise
 */

public static boolean streamToFile(final InputStream inputStream, final File targetFile)
/**
 * Writes a stream to a file (overwrites existing file)
 *
 * @param inputStream - input stream
 * @param targetFile  - File to create
 * @return true if all OK or false otherwise
 */

public static boolean streamToFile(final InputStream inputStream, final File targetFile, final boolean doAppend)
/**
 * Writes a stream to a file
 *
 * @param inputStream - input stream
 * @param targetFile  - File to create
 * @param doAppend    - append mode on/off
 * @return true if all OK or false otherwise
 */

public static boolean byteArrayOutputStreamToFile(final ByteArrayOutputStream bos, final File targetFile)
/**
 * Writes a byte array to a file  (overwrites existing file)
 *
 * @param bos        - ByteArrayOutputStream
 * @param targetFile - File to create
 * @return true if all OK or false otherwise
 */

public static boolean byteArrayOutputStreamToFile(final ByteArrayOutputStream bos, final File targetFile, final boolean doAppend) {
/**
 * Writes a byte array to a file.
 *
 * @param bos        - ByteArrayOutputStream
 * @param targetFile - File to create
 * @param doAppend   - append mode on/off
 * @return true if all OK or false otherwise
 */

public static boolean byteArrayToFile(final byte[] array, final File targetFile) {
/**
 * Writes a byte array to a file  (overwrites existing file)
 *
 * @param array      - byte[]
 * @param targetFile - File to create
 * @return true if all OK or false otherwise
 */

public static boolean byteArrayToFile(final byte[] array, final File targetFile, final boolean doAppend) {
/**
 * Writes a byte array to a file.
 *
 * @param array      - byte[]
 * @param targetFile - File to create
 * @param doAppend   - append mode on/off
 * @return true if all OK or false otherwise
 */


public static boolean intentDataToFile(final Context context, final Uri uri, final String targetFile) {
/**
 * Method creates a File from intent's data
 *
 * @param context    - Context
 * @param uri        - Uri taken from Intent.detData()
 * @param targetFile - File to create
 * @return true if all OK or false otherwise
 */

public static boolean intentDataToFile(final Context context, final Uri uri, final File targetFile) {
/**
 * Method creates a File from intent's data
 *
 * @param context    - Context
 * @param uri        - Uri taken from Intent.detData()
 * @param targetFile - File to create
 * @return true if all OK or false otherwise
 */

public static boolean makeDirsForFile(final String file) {
/**
 * Method creates the FILE's path dirs and returns true if succeed. The difference
 * from File.mkdirs() is that mkdirs() returns false in both cases:
 * it can't create path OR path already exists. This method will return
 * false if path could not be created only.
 *
 * @param file - File only the not a Directory!
 * @return true if file's path created/exists or false if path could not be created
 */

public static boolean makeDirsForFile(final File file) {
/**
 * Method creates the FILE's path dirs and returns true if succeed. The difference
 * from File.mkdirs() is that mkdirs() returns false in both cases:
 * it can't create path OR path already exists. This method will return
 * false if path could not be created only.
 *
 * @param file - File only the not a Directory!
 * @return true if file's path created/exists or false if path could not be created
 */

public static boolean isWritable(final String file) {
/**
 * Method checks if file could be written/deleted or created. Does not create path/mkdirs so if path doesn't exists returns false.
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean isWritable(final File file) {
/**
 * Method checks if file could be written/deleted or created. Does not create path/mkdirs so if path doesn't exists returns false.
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean isWritable(final String file, final boolean makeDirs) {
/**
 * Method checks if file could be written/deleted or created. Method will create path/mkdirs if makeDirs set to true and file's path doesn't exists.
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean isWritable(final File file, final boolean makeDirs) {
/**
 * Method checks if file could be written/deleted or created. Method will create path/mkdirs if makeDirs set to true and file's path doesn't exists.
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean isReadable(final String file) {
/**
 * Method checks if file could be read or created
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean isReadable(final File file) {
/**
 * Method checks if file could be read or created
 *
 * @param file - File only not a Directory!
 * @return true if file's is writable or false otherwise
 */

public static boolean sync(final OutputStream stream) {
/**
 * Method ensures about file creation from stream. For Samsung like devices
 *
 * @param stream - OutputStream
 * @return true if all OK or false otherwise
 */

public static boolean sync(final FileOutputStream stream) {
/**
 * Method ensures about file creation from stream. For Samsung like devices
 *
 * @param stream - FileOutputStream
 * @return true if all OK or false otherwise
 */

public static boolean syncAndClose(final FileOutputStream stream) {
/**
 * Method ensures about file creation from stream. For Samsung like devices
 *
 * @param stream - FileOutputStream
 * @return true if all OK or false otherwise
 */


public static boolean deleteFilesAndDirsRecursive(final String file) {
/**
 * Method deletes all files and subdirectories recursively from given directory.
 * Returns true if all files deleted false if at least one doesn't
 *
 * @param file - File which represents a directory where to delete all files and dirs
 */

public static boolean deleteFilesAndDirsRecursive(final File directory) {
/**
 * Method deletes all files and subdirectories recursively from given directory.
 * Returns true if all files deleted false if at least one doesn't
 *
 * @param directory - File which represents a directory where to delete all files and dirs
 */

public static boolean deleteFiles(final File targetDir) {
/**
 * Method deletes all files only (but NOT subdirectories) from given directory.
 * Returns true if all files deleted false if at least one doesn't
 *
 * @param targetDir - File with represents a Directory where to delete all files
 */

public static boolean isFileExists(final String path) {
/**
 * Check if given path is a File and if it exists
 *
 * @param path - the path to check
 * @return boolean
 */

public static long getAvailableSpace(final File file) {
/**
 * Returns the free space in bytes available at the given file's path
 * or -1 if storage is not available (UNMOUNTED, etc)
 *
 * @return long
 */

public static long getAvailableSpace(final Uri uri) {
/**
 * Returns the free space in bytes available at the given file's path
 * or -1 if storage is not available (UNMOUNTED, etc)
 *
 * @return long
 */

public static long getAvailableSpace(String mFileRootPath) {
/**
 * Returns the free space in bytes available at the given file's path
 * or -1 if storage is not available (UNMOUNTED, etc)
 *
 * @return long
 */


public static String[] getFilenamesByExtension(final File directory, final String extension) {
/**
 * returns list of given directory files as String[]
 *
 * @param directory - File representing directory
 * @param extension - String representing file's extension, e.g. "png" or ".jpeg" (including or excluding starting dot)
 * @return String [] with files list
 */

public static File[] getFilesByExtension(final File directory, final String extension) {
/**
 * creates File[] containing files located in given directory
 *
 * @param directory - File representing directory
 * @param extension - String representing file's extension, e.g. "png" or ".jpeg" (including or excluding starting dot)
 * @return File[] with files list
 */


public static File getFileFromUri(final Context context, final Uri uri) {
/**
 * Retrieves a File path represented by given Uri
 * 
 * @param context
 * @param uri
 * @return
 */

public static String getPathFromUri(final Context context, final Uri uri) {
/**
 * Retrieves a String path represented by given Uri. Uses DocumentsContract for API 19.
 * 
 * @param context
 * @param uri
 * @return
 */

public static String getDataColumn(final Context context, final Uri uri, final String selection, final String[] selectionArgs) {
/**
 * Get the value of the data column for this Uri. This is useful for
 * MediaStore Uris, and other file-based ContentProviders.
 *
 * @param context       The context.
 * @param uri           The Uri to query.
 * @param selection     (Optional) Filter used in the query.
 * @param selectionArgs (Optional) Selection arguments used in the query.
 * @return The value of the _data column, which is typically a file path.
 */


public static boolean isExternalStorageDocument(final Uri uri) {
/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is ExternalStorageProvider.
 */

public static boolean isDownloadsDocument(final Uri uri) {
/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is DownloadsProvider.
 */

public static boolean isMediaDocument(final Uri uri) {
/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is MediaProvider.
 */

public static void mergeFiles(final File file1, final File file2, final File outputFile) {
/**
 * Merge two files into a new file
 *
 * @param file1      - File to merge (will be first in resulting file)
 * @param file2      - File to merge (will be second in resulting file)
 * @param outputFile - resulting File
 */

public static void appendFileToFile(final File file1, final File file2) {
/**
 * Appends one file to another.
 *
 * @param file1 - file to append to
 * @param file2 - file being append to file1
 */

public static String getBase64EncodedFile(final File fileToEncode) {
/**
 * Returns a Base64.DEFAULT encoded String representation of given file
 * Aware of OOM: large files will probably cause it.
 *
 * @param fileToEncode
 * @return
 */

public static class ExtensionFilter implements FilenameFilter {
/**
 * Represents extension for filtering for File.list()
 */