Package org.apache.commons.lang3

Class CharSequenceUtils

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) static int TO_STRING_LIMIT  

    • Constructor Summary

      Constructors 
      Constructor Description
      CharSequenceUtils()
      CharSequenceUtils instances should NOT be constructed in standard programming.

    • Constructor Detail

      • CharSequenceUtils

        public CharSequenceUtils()

        CharSequenceUtils instances should NOT be constructed in standard programming.

        This constructor is public to permit tools that require a JavaBean instance to operate.

    • Method Detail

      • subSequence

        public static CharSequence subSequence​(CharSequence cs,
                                       int start)

        Returns a new CharSequence that is a subsequence of this sequence starting with the char value at the specified index.

        This provides the CharSequence equivalent to String.substring(int). The length (in char) of the returned sequence is length() - start, so if start == end then an empty sequence is returned.

        Parameters:
        cs - the specified subsequence, null returns null
        start - the start index, inclusive, valid
        Returns:
        a new subsequence, may be null
        Throws:
        IndexOutOfBoundsException - if start is negative or if start is greater than length()

      • indexOf

        static int indexOf​(CharSequence cs,
                   int searchChar,
                   int start)
        Returns the index within cs of the first occurrence of the specified character, starting the search at the specified index.

        If a character with value searchChar occurs in the character sequence represented by the cs object at an index no smaller than start, then the index of the first such occurrence is returned. For values of searchChar in the range from 0 to 0xFFFF (inclusive), this is the smallest value k such that: 

         (this.charAt(k) == searchChar) && (k >= start)
        is true. For other values of searchChar, it is the smallest value k such that: 
         (this.codePointAt(k) == searchChar) && (k >= start)
        is true. In either case, if no such character occurs inm cs at or after position start, then -1 is returned.

        There is no restriction on the value of start. If it is negative, it has the same effect as if it were zero: the entire CharSequence may be searched. If it is greater than the length of cs, it has the same effect as if it were equal to the length of cs: -1 is returned.

        All indices are specified in char values (Unicode code units).

        Parameters:
        cs - the CharSequence to be processed, not null
        searchChar - the char to be searched for
        start - the start index, negative starts at the string start
        Returns:
        the index where the search char was found, -1 if not found
        Since:
        3.6 updated to behave more like String

      • indexOf

        static int indexOf​(CharSequence cs,
                   CharSequence searchChar,
                   int start)
        Used by the indexOf(CharSequence methods) as a green implementation of indexOf.
        Parameters:
        cs - the CharSequence to be processed
        searchChar - the CharSequence to be searched for
        start - the start index
        Returns:
        the index where the search sequence was found

      • lastIndexOf

        static int lastIndexOf​(CharSequence cs,
                       int searchChar,
                       int start)
        Returns the index within cs of the last occurrence of the specified character, searching backward starting at the specified index. For values of searchChar in the range from 0 to 0xFFFF (inclusive), the index returned is the largest value k such that: 
         (this.charAt(k) == searchChar) && (k <= start)
        is true. For other values of searchChar, it is the largest value k such that: 
         (this.codePointAt(k) == searchChar) && (k <= start)
        is true. In either case, if no such character occurs in cs at or before position start, then -1 is returned.

        All indices are specified in char values (Unicode code units).

        Parameters:
        cs - the CharSequence to be processed
        searchChar - the char to be searched for
        start - the start index, negative returns -1, beyond length starts at end
        Returns:
        the index where the search char was found, -1 if not found
        Since:
        3.6 updated to behave more like String

      • lastIndexOf

        static int lastIndexOf​(CharSequence cs,
                       CharSequence searchChar,
                       int start)
        Used by the lastIndexOf(CharSequence methods) as a green implementation of lastIndexOf
        Parameters:
        cs - the CharSequence to be processed
        searchChar - the CharSequence to find
        start - the start index
        Returns:
        the index where the search sequence was found

      • toCharArray

        public static char[] toCharArray​(CharSequence source)
        Converts the given CharSequence to a char[].
        Parameters:
        source - the CharSequence to be processed.
        Returns:
        the resulting char array, never null.
        Since:
        3.11

      • regionMatches

        static boolean regionMatches​(CharSequence cs,
                             boolean ignoreCase,
                             int thisStart,
                             CharSequence substring,
                             int start,
                             int length)
        Green implementation of regionMatches.
        Parameters:
        cs - the CharSequence to be processed
        ignoreCase - whether or not to be case insensitive
        thisStart - the index to start on the cs CharSequence
        substring - the CharSequence to be looked for
        start - the index to start on the substring CharSequence
        length - character length of the region
        Returns:
        whether the region matched