### Question:
StringProcessor { public static String getHexFromBytes(byte[] bytes) { StringBuilder hexString = new StringBuilder(); for (int i = 0; i < bytes.length; i++) { if ((0xff & bytes[i]) < 0x10) { hexString.append("0").append(Integer.toHexString((0xFF & bytes[i]))); } else { hexString.append(Integer.toHexString(0xFF & bytes[i])); } } return hexString.toString(); }  static ObjectMapper defaultObjectMapper(); static String getResourceNameFromUrl(String url); static String getJustFileName(String originalFilename); static List<String> extractUrls(String text); static String stripeExtendedChars(String data); static String createHrefUrls(String text); static String createHrefUrls(String text, boolean showFullURL); static String stripeFieldJSON(String json, Set<String> fieldsToKeep); static String printObject(Object o); static String ellipseString(String data, int max_length); static String blankIfNull(String text); static String blankIfNull(Object text); static String nullIfBlank(String text); static Boolean isEmail(String text); static String stripHtml(String text); static BigDecimal archtecureCodeToDecimal(String code); static String urlEncode(String value); static String urlDecode(String value); static String parseStackTraceHtml(Throwable throwable); static String enclose(String s); static String enclose(String s, String enclose); static String enclose(String s, String encloseStart, String encloseEnd); static String encodeWebKey(String key); static String cleanEntityKey(String key); static String getFileExtension(String filename); static String cleanFileName(String badFileName); static String puralize(int size, String nonPuralForm, String puralForm); static String getHexFromBytes(byte[] bytes); static String decodeHexCharEscapes(String input); static boolean stringIsNotBlank(String input); static String formatForFilename(String input); static String uniqueId(); static String truncateHTML(String html, int maxCharCount); static Map<String, List<String>> splitURLQuery(String query); static String removeBadStyles(String html); static String escapeHtmlQuotes(String input);  }### Answer:
@Test public void testGetHexFromBytes() throws NoSuchAlgorithmException { System.out.println("testGetHexFromBytes:"); String imgUrl = "http: String hashUrl = StringProcessor.getHexFromBytes(MessageDigest.getInstance("SHA-1").digest(imgUrl.getBytes())); String expHashUrl = "bdea7192ed2dfcd01ad525d0ab8ce2b48ab16c95"; assertEquals(hashUrl, expHashUrl); imgUrl = "https: hashUrl = StringProcessor.getHexFromBytes(MessageDigest.getInstance("SHA-1").digest(imgUrl.getBytes())); expHashUrl = "1b53f7dd4d03adae30fcad1fc19e7301fafad174"; assertEquals(hashUrl, expHashUrl); }