Class StringUtil


  • public class StringUtil
    extends Object
    Some text related utilities.
    • Constructor Detail

      • StringUtil

        public StringUtil()
    • Method Detail

      • HTMLEnc

        public static String HTMLEnc​(String s)
        Deprecated.
        Use XHTMLEnc(String) instead, because it escapes apostrophe-quote too.
        HTML encoding (does not convert line breaks and apostrophe-quote). Replaces all '>' '<' '&' and '"' with entity reference, but not "'" (apostrophe-quote). The last is not escaped as back then when this was written some user agents didn't understood "&apos;" nor "&#39;".
      • XMLEnc

        public static String XMLEnc​(String s)
        XML Encoding. Replaces all '>' '<' '&', "'" and '"' with entity reference
      • XHTMLEnc

        public static String XHTMLEnc​(String s)
        XHTML Encoding. Replaces all '>' '<' '&', "'" and '"' with entity reference suitable for XHTML decoding in common user agents (including legacy user agents, which do not decode "&apos;" to "'", so "&#39;" is used instead [see http://www.w3.org/TR/xhtml1/#C_16])
      • XMLEncQAttr

        public static String XMLEncQAttr​(String s)
        XML encoding for attributes values quoted with " (not with '!). Also can be used for HTML attributes that are quoted with ".
        See Also:
        XMLEnc(String)
      • XMLEncNQG

        public static String XMLEncNQG​(String s)
        XML encoding without replacing apostrophes and quotation marks and greater-thans (except in ]]>).
        See Also:
        XMLEnc(String)
      • RTFEnc

        public static String RTFEnc​(String s)
        Rich Text Format encoding (does not replace line breaks). Escapes all '\' '{' '}' and '"'
      • FTLStringLiteralEnc

        public static String FTLStringLiteralEnc​(String s,
                                                 char quotation)
        Escapes a string according the FTL string literal escaping rules, assuming the literal is quoted with quotation; it doesn't add the quotation marks itself.
        Parameters:
        quotation - Either '"' or '\''. It's assumed that the string literal whose part we calculate is enclosed within this kind of quotation mark. Thus, the other kind of quotation character will not be escaped in the result.
        Since:
        2.3.22
      • FTLStringLiteralEnc

        public static String FTLStringLiteralEnc​(String s)
        Escapes a string according the FTL string literal escaping rules; it doesn't add the quotation marks. As this method doesn't know if the string literal is quoted with reuglar quotation marks or apostrophe quute, it will escape both.
        See Also:
        FTLStringLiteralEnc(String, char)
      • FTLStringLiteralDec

        public static String FTLStringLiteralDec​(String s)
                                          throws ParseException
        FTL string literal decoding. \\, \", \', \n, \t, \r, \b and \f will be replaced according to Java rules. In additional, it knows \g, \l, \a and \{ which are replaced with <, >, & and { respectively. \x works as hexadecimal character code escape. The character codes are interpreted according to UCS basic plane (Unicode). "f\x006Fo", "f\x06Fo" and "f\x6Fo" will be "foo". "f\x006F123" will be "foo123" as the maximum number of digits is 4. All other \X (where X is any character not mentioned above or End-of-string) will cause a ParseException.
        Parameters:
        s - String literal without the surrounding quotation marks
        Returns:
        String with all escape sequences resolved
        Throws:
        ParseException - if there string contains illegal escapes
      • deduceLocale

        public static Locale deduceLocale​(String input)
      • capitalize

        public static String capitalize​(String s)
      • getYesNo

        public static boolean getYesNo​(String s)
      • split

        public static String[] split​(String s,
                                     char c)
        Splits a string at the specified character.
      • split

        public static String[] split​(String s,
                                     String sep,
                                     boolean caseInsensitive)
        Splits a string at the specified string.
      • replace

        public static String replace​(String text,
                                     String oldsub,
                                     String newsub,
                                     boolean caseInsensitive,
                                     boolean firstOnly)
        Replaces all occurrences of a sub-string in a string.
        Parameters:
        text - The string where it will replace oldsub with newsub.
        Returns:
        String The string after the replacements.
      • chomp

        public static String chomp​(String s)
        Removes the line-break from the end of the string.
      • emptyToNull

        public static String emptyToNull​(String s)
        Converts a 0-length string to null, leaves the string as is otherwise.
        Parameters:
        s - maybe null.
      • jQuote

        public static String jQuote​(Object obj)
        Converts the parameter with toString (if it's not null) and passes it to jQuote(String).
      • jQuote

        public static String jQuote​(String s)
        Quotes string as Java Language string literal. Returns string "null" if s is null.
      • jQuoteNoXSS

        public static String jQuoteNoXSS​(String s)
        Same as jQuoteNoXSS(String) but also escapes '<' as \u003C. This is used for log messages to prevent XSS on poorly written Web-based log viewers.
      • ftlQuote

        public static String ftlQuote​(String s)
        Creates a quoted FTL string literal from a string, using escaping where necessary. The result either uses regular quotation marks (UCS 0x22) or apostrophe-quotes (UCS 0x27), depending on the string content. (Currently, apostrophe-quotes will be chosen exactly when the string contains regular quotation character and doesn't contain apostrophe-quote character.)
        Parameters:
        s - The value that should be converted to an FTL string literal whose evaluated value equals to s
        Since:
        2.3.22
      • isFTLIdentifierStart

        public static boolean isFTLIdentifierStart​(char c)
        Tells if a character can occur on the beginning of an FTL identifier expression (without escaping).
        Since:
        2.3.22
      • isFTLIdentifierPart

        public static boolean isFTLIdentifierPart​(char c)
        Tells if a character can occur in an FTL identifier expression (without escaping) as other than the first character.
        Since:
        2.3.22
      • javaStringEnc

        public static String javaStringEnc​(String s)
        Escapes the String with the escaping rules of Java language string literals, so it's safe to insert the value into a string literal. The resulting string will not be quoted.

        All characters under UCS code point 0x20 will be escaped. Where they have no dedicated escape sequence in Java, they will be replaced with hexadecimal escape (\uXXXX).

        See Also:
        jQuote(String)
      • jsStringEnc

        public static String jsStringEnc​(String s,
                                         boolean json)
        Escapes a String to be safely insertable into a JavaScript or a JSON string literal. The resulting string will not be quoted; the caller must ensure that they are there in the final output. Note that for JSON, the quotation marks must be ", not ', because JSON doesn't escape '.

        The escaping rules guarantee that if the inside of the literal is from one or more touching sections of strings escaped with this, no character sequence will occur that closes the string literal or has special meaning in HTML/XML that can terminate the script section. (If, however, the escaped section is preceded by or followed by strings from other sources, this can't be guaranteed in some rare cases. Like x = "</${a?js_string}" might closes the "script" element if a is is "script>".) The escaped characters are:

        Input Output
        " \"
        ' if not in JSON-mode \'
        \ \\
        / if the method can't know that it won't be directly after < \/
        > if the method can't know that it won't be directly after ]] or -- JavaScript: \>; JSON: \u003E
        < if the method can't know that it won't be directly followed by ! or ? \u003C
        u0000-u001f (UNICODE control characters - disallowed by JSON)
        u007f-u009f (UNICODE control characters - disallowed by JSON)
        \n, \r and such, or if there's no such dedicated escape: JavaScript: \xXX, JSON: \uXXXX
        u2028 (Line separator - source code line-break in ECMAScript)
        u2029 (Paragraph separator - source code line-break in ECMAScript)
        \uXXXX
        Since:
        2.3.20
      • parseNameValuePairList

        public static Map parseNameValuePairList​(String s,
                                                 String defaultValue)
                                          throws ParseException
        Parses a name-value pair list, where the pairs are separated with comma, and the name and value is separated with colon. The keys and values can contain only letters, digits and _. They can't be quoted. White-space around the keys and values are ignored. The value can be omitted if defaultValue is not null. When a value is omitted, then the colon after the key must be omitted as well. The same key can't be used for multiple times.
        Parameters:
        s - the string to parse. For example: "strong:100, soft:900".
        defaultValue - the value used when the value is omitted in a key-value pair.
        Returns:
        the map that contains the name-value pairs.
        Throws:
        ParseException - if the string is not a valid name-value pair list.
      • isXMLID

        public static boolean isXMLID​(String name)
        Returns:
        whether the name is a valid XML tagname. (This routine might only be 99% accurate. Should maybe REVISIT)
      • matchesName

        public static boolean matchesName​(String qname,
                                          String nodeName,
                                          String nsURI,
                                          Environment env)
        Returns:
        whether the qname matches the combination of nodeName, nsURI, and environment prefix settings.
      • leftPad

        public static String leftPad​(String s,
                                     int minLength)
        Pads the string at the left with spaces until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string.
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
      • leftPad

        public static String leftPad​(String s,
                                     int minLength,
                                     char filling)
        Pads the string at the left with the specified character until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string.
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
        filling - the filling pattern.
      • leftPad

        public static String leftPad​(String s,
                                     int minLength,
                                     String filling)
        Pads the string at the left with a filling pattern until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string. For example: leftPad('ABC', 9, '1234') returns "123412ABC".
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
        filling - the filling pattern. Must be at least 1 characters long. Can't be null.
      • rightPad

        public static String rightPad​(String s,
                                      int minLength)
        Pads the string at the right with spaces until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string.
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
      • rightPad

        public static String rightPad​(String s,
                                      int minLength,
                                      char filling)
        Pads the string at the right with the specified character until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string.
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
        filling - the filling pattern.
      • rightPad

        public static String rightPad​(String s,
                                      int minLength,
                                      String filling)
        Pads the string at the right with a filling pattern until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string. For example: rightPad('ABC', 9, '1234') returns "ABC412341". Note that the filling pattern is started as if you overlay "123412341" with the left-aligned "ABC", so it starts with "4".
        Parameters:
        s - the string that will be padded.
        minLength - the length to reach.
        filling - the filling pattern. Must be at least 1 characters long. Can't be null.
      • versionStringToInt

        public static int versionStringToInt​(String version)
        Converts a version number string to an integer for easy comparison. The version number must start with numbers separated with dots. There can be any number of such dot-separated numbers, but only the first three will be considered. After the numbers arbitrary text can follow, and will be ignored. The string will be trimmed before interpretation.
        Returns:
        major * 1000000 + minor * 1000 + micro
      • tryToString

        public static String tryToString​(Object object)
        Tries to run toString(), but if that fails, returns a "[com.example.SomeClass.toString() failed: " + e + "]" instead. Also, it returns null for null parameter.
        Since:
        2.3.20
      • toUpperABC

        public static String toUpperABC​(int n)
        Converts 1, 2, 3 and so forth to "A", "B", "C" and so fort. When reaching "Z", it continues like "AA", "AB", etc. The lowest supported number is 1, but there's no upper limit.
        Throws:
        IllegalArgumentException - If the argument is 0 or less.
        Since:
        2.3.22
      • toLowerABC

        public static String toLowerABC​(int n)
        Same as toUpperABC(int), but produces lower case result, like "ab".
        Since:
        2.3.22
      • trim

        public static char[] trim​(char[] cs)
        Behaves exactly like String.trim(), but works on arrays. If the resulting array would have the same content after trimming, it returns the original array instance. Otherwise it returns a new array instance (or CollectionUtils.EMPTY_CHAR_ARRAY).
        Since:
        2.3.22
      • isTrimmableToEmpty

        public static boolean isTrimmableToEmpty​(char[] text)
        Tells if String.trim() will return a 0-length string for the String equivalent of the argument.
        Since:
        2.3.22
      • isTrimmableToEmpty

        public static boolean isTrimmableToEmpty​(char[] text,
                                                 int start)
        Like isTrimmableToEmpty(char[]), but acts on a sub-array that starts at start (inclusive index).
        Since:
        2.3.23
      • isTrimmableToEmpty

        public static boolean isTrimmableToEmpty​(char[] text,
                                                 int start,
                                                 int end)
        Like isTrimmableToEmpty(char[]), but acts on a sub-array that starts at start (inclusive index) and ends at end (exclusive index).
        Since:
        2.3.23