Check if the value is non-null, not empty, and not all white-space.

@return {@code false} if the string has characters, {@code true} otherwise.
971184
@Trivial
    private boolean isStringValueUndefined(Object str) {
        if (str instanceof SerializableProtectedString) {
            // Avoid constructing a String from a ProtectedString
            char[] contents = ((SerializableProtectedString) str).getChars();
            for (char ch : contents)
                if (ch > '\u0020')
                    return false; // See the description of String.trim()
            return true;
        } else {
            return (str == null || ((String) str).trim().isEmpty());
        }

    }
1326499
public static boolean isNullOrEmpty(@Nullable String string)
  {
    if (string == null || string.isEmpty())
    {
      return true;
    }
    return false;
  }
1355863
public static boolean isDelimiter(String str)
    {
        if (str != null && ("-".equals(str) || "－".equals(str)))
            return true;
        else
            return false;
    }
655523
public static boolean isNullOrEmptyOrQuestionMark(final String string) {
        if (string == null || string.length() == 0 || "?".equals(string)) {
            return true;
        }
        return false;
    }
877668
public static boolean containsWhitespace(final CharSequence seq) {
        if (isEmpty(seq)) {
            return false;
        }
        final int strLen = seq.length();
        for (int i = 0; i < strLen; i++) {
            if (CharUtils.isWhitespace(seq.charAt(i))) {
                return true;
            }
        }
        return false;
    }
403410
private boolean isNullOrEmpty(Object paramValue) {
        boolean isNullOrEmpty = false;
        if (paramValue == null) {
            isNullOrEmpty = true;
        }
        if (paramValue instanceof String) {
            if (((String) paramValue).trim().equalsIgnoreCase("")) {
                isNullOrEmpty = true;
            }
        } else if (paramValue instanceof List) {
            return ((List) paramValue).isEmpty();
        }
        return isNullOrEmpty;
    }
1325759
protected boolean isAllWhiteSpace(CharSequence sb) {
        boolean result = true;
        for (int i = 0; i < sb.length(); i++) {
            char c = sb.charAt(i);

            if (!Character.isWhitespace(c)) {
                return false;
            }
        }
        return result;
    }
984663
private static boolean checkTokenValid(final char[] token) {
        if (token == null || token.length == 0) {
            return true;
        }
        for (int i = 0; i < token.length; i++) {
            if (token[i] == '\n') {
                return false;
            }

        }
        return true;
    }
441347
public static boolean isValid(final String value) {
        if (value == null) {
            return true;
        }
        if (value.length() == 0) {
            return false;
        }
        final int space = value.indexOf(' ');
        if (space == -1) {
            return false;
        }

        // Try converting amount
        final String amount = value.substring(0, space);
        if (!(amount.matches(DECIMAL) || amount.matches(INTEGER))) {
            return false;
        }

        // Try to convert code into a currency
        final String currencyCode = value.substring(space + 1);
        try {
            Currency.getInstance(currencyCode);
        } catch (RuntimeException ex) {
            return false;
        }

        return true;
    }
989940
public boolean isValueSet(String s) {
        return (s != null && s.trim().isEmpty() == false) ? true : false;
    }
963298
private boolean tryWhitespace() throws SAXException, IOException {
        char c;
        c = readCh();
        if (isWhitespace(c)) {
            skipWhitespace();
            return true;
        } else {
            unread(c);
            return false;
        }
    }
508488
@Pure
	public boolean isNull() {
		for (int i = 0; i < this.bytes.length; ++i) {
			if (this.bytes[i] != 0) {
				return false;
			}
		}
		return true;
	}
476602
public static boolean isValidLong(@Nullable final String longStr) {
        if (StringUtils.isBlank(longStr)) {
            return false;
        }
        final String stripedLong = StringUtils.strip(longStr);
        try {
            NumberUtils.createLong(stripedLong);
            return true;
        } catch (NumberFormatException e) {
            return false;
        }
    }
669637
public static boolean isFloat(String s) {
        if (isEmpty(s)) return defaultEmptyOK;

        boolean seenDecimalPoint = false;

        if (s.startsWith(decimalPointDelimiter)) return false;

        // Search through string's characters one by one
        // until we find a non-numeric character.
        // When we do, return false; if we don't, return true.
        for (int i = 0; i < s.length(); i++) {
            // Check that current character is number.
            char c = s.charAt(i);

            if (c == decimalPointDelimiter.charAt(0)) {
                if (!seenDecimalPoint)
                    seenDecimalPoint = true;
                else
                    return false;
            } else {
                if (!isDigit(c)) return false;
            }
        }
        // All characters are numbers.
        return true;
    }
1088511
public static boolean isEmpty(Object value) {
		return (null == value || (value instanceof String && StrUtil.isEmpty((String) value)));
	}
935454
public static boolean isWhitespace(CharSequence str){
        if(str!=null){
            for(int i=0; i<str.length(); i++){
                if(!Character.isWhitespace(str.charAt(i)))
                    return false;
            }
        }
        return true;
    }
14242
public static boolean isValid(String token)
    {
        if (token == null || token.length() == 0)
        {
            return false;
        }

        int len = token.length();

        for (int i = 0; i < len; ++i)
        {
            if (isSeparator(token.charAt(i)))
            {
                return false;
            }
        }

        return true;
    }