### Question:
Files { public static byte[] calculateMD5(File file) throws IOException { checkIfFileExist(file); return IOs.calculateMD5(new FileInputStream(file)); } private  Files(); static Comparator<File> getNameSortingComparator(final Locale locale); static Comparator<File> getNameSortingComparator(); static FileFilter extensionFilter(String... extensions); static void deleteFiles(File... files); static void deleteFilesAndDirs(File... files); static List<File> crawlDirectory(File dir); static List<File> getFilesSorted(File dir, Comparator<File> comparator); static List<File> getFilesSorted(File dir, Comparator<File> comparator, FileFilter... filters); static List<File> crawlDirectory(File dir, FileFilter... filters); static List<File> crawlDirectory(File dir, boolean recurseSubDirs, FileFilter... filters); static List<File> getDirectories(File rootDir, boolean recurseSubDirs); static byte[] calculateMD5(File file); static void copyDirectory(File srcDir, File dstDir); static void copy(File src, File dst); static boolean contentEquals(File file1, File file2); static boolean containsUTF8Bom(File file); static void appendFiles(File target, File... filesToAppend); static void appendFiles(OutputStream os, File... filesToAppend); static void hexDump(File f, long amount); static void hexDump(File f, File out, long amount); static final Comparator<File> FILE_MODIFICATION_TIME_COMPARATOR_ASC; static final Comparator<File> FILE_MODIFICATION_TIME_COMPARATOR_DESC; }### Answer:
@Test public void MD5CalculationTest() throws IOException { assertEquals("873362e429c261e3596ad1d387ad152e", Bytes.toHex(Files.calculateMD5(new File("test/file_for_md5.txt")))); }