### Question:
StringUtil { public static String split(String src, char separator, int tokenSize) { StringBuffer sb = new StringBuffer(); String[] tokens = split(src, tokenSize); for (int i = 0; i < tokens.length; i++) { if (sb.length() > 0) sb.append(separator); sb.append(tokens[i]); } return sb.toString(); }  static String split(String src, char separator, int tokenSize); static String[] split(String src, int tokenSize); static String writeToString(Reader reader); static String writeToString(Reader reader, String targetEncoding); static String writeToString(InputStream is, String targetEncoding); static String arrayToString(Object[] a, String separator); static String collectionToString(Collection<?> collection, String separator); static String removeNonUtf8Chars(String src); static boolean matches(String str, String[] includes, String[] excludes); static String unaccent(String src);  }### Answer:
@Test public void testSplit() { String str="1"; assertEquals("1", StringUtil.split(str, '/', 3)); str="12"; assertEquals("12", StringUtil.split(str, '/', 3)); str="123"; assertEquals("123", StringUtil.split(str, '/', 3)); str="1234"; assertEquals("123/4", StringUtil.split(str, '/', 3)); str="123456"; assertEquals("123/456", StringUtil.split(str, '/', 3)); str="12345678"; assertEquals("123/456/78", StringUtil.split(str, '/', 3)); System.out.println("Crypt J2A86bc26QnIpf1:"+CryptUtil.cryptString("J2A86bc26QnIpf1")); }