### Question:
StringValidateEncodeUtils { public static boolean validSingleLineString(String singleLineString) { if (singleLineString == null) return false; Matcher m = INVALID_CHARACTERS_FOR_SINGLE_LINE_STRING_PATTERN.matcher(singleLineString); return !m.find(); } private  StringValidateEncodeUtils(); static boolean validSingleLineString(String singleLineString); @SuppressWarnings({"SimplifiableIfStatement"}) static boolean validPath(String path); @SuppressWarnings({"SimplifiableIfStatement"}) static boolean validFilePath(String path); @SuppressWarnings({"SimplifiableIfStatement"}) static boolean validUriString(String uri); static boolean validIdString(String id); static boolean containsAngleBracketCharacters(String string); static boolean containsAmpersandCharacters(String string); static boolean containsBackslashCharacters(String string); static boolean validDecimalNumber(String number); @SuppressWarnings({"SimplifiableIfStatement"}) static boolean validBooleanString(String boolString); static boolean validAlphanumericString(String alphNumString); static boolean validAlphanumericStringConstrainedSet(String alphNumString, String[] constrainedSet,
      boolean ignoreCase); @SuppressWarnings({"UnnecessaryContinue"}) static boolean descendOnlyFilePath(String path); static boolean validPercentHexOctetsString(String percentHexOctetsString); static String unicodeCodePoint2PercentHexString(int codePoint, String charsetName); final static String CHARACTER_ENCODING_UTF_8; }### Answer:
@Test public void testValidSingleLineString() { String begin = "a really co"; String end = "ol string"; assertTrue("Invalid string when no extra character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + end)); assertTrue("Invalid string when [Latin small letter eth] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\u00F0' + end)); assertTrue("Invalid string when [space] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + ' ' + end)); assertTrue("Invalid string when [File.pathSeparatorChar] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + File.pathSeparatorChar + end)); assertTrue("Invalid string when [less than] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '<' + end)); assertTrue("Invalid string when [greater than] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '>' + end)); assertTrue("Invalid string when [ampersand] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '&' + end)); assertTrue("Invalid string when [backslash] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\\' + end)); assertTrue("Invalid string when [up directory path] string inserted.", StringValidateEncodeUtils.validSingleLineString(begin + "/../" + end)); assertFalse("Invalid string when [line feed] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\n' + end)); assertFalse("Invalid string when [carriage return] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\r' + end)); assertFalse("Invalid string when [tab] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\t' + end)); assertFalse("Invalid string when [line separator] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\u2028' + end)); assertFalse("Invalid string when [paragraph separator] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\u2029' + end)); assertFalse("Valid string when [bell] character inserted.", StringValidateEncodeUtils.validSingleLineString(begin + '\u0007' + end)); }