Package com.alibaba.nacos.client.identify

Class Base64

  • public class Base64
extends Object
    Provides Base64 encoding and decoding as defined by RFC 2045.

    This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.

    The class can be parameterized in the following manner with various constructors:

    • URL-safe mode: Default off.
    • Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
    • Line separator: Default is CRLF ("\r\n")

    Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).

    This class is not thread-safe. Each thread should use its own instance.

    Since:
    1.0
    Version:
    $Revision: 1080712 $
    Author:
    Apache Software Foundation
    See Also:
    RFC 2045

    • Constructor Summary

      Constructors 
      Constructor Description
      Base64()
      Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
      Base64​(int lineLength, byte[] lineSeparator, boolean urlSafe)
      Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

    • Constructor Detail

      • Base64

        public Base64()
        Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

        When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE.

        When decoding all variants are supported.

      • Base64

        public Base64​(int lineLength,
              byte[] lineSeparator,
              boolean urlSafe)
        Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

        When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE.

        Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.

        When decoding all variants are supported.

        Parameters:
        lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
        lineSeparator - Each line of encoded data will end with this sequence of bytes.
        urlSafe - Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly handles both modes.
        Throws:
        IllegalArgumentException - The provided lineSeparator included some base64 characters. That's not going to work!
        Since:
        1.4

    • Method Detail

      • encodeBase64

        public static byte[] encodeBase64​(byte[] binaryData)
        Encodes binary data using the base64 algorithm but does not chunk the output.
        Parameters:
        binaryData - binary data to encode
        Returns:
        byte[] containing Base64 characters in their UTF-8 representation.

      • encodeBase64

        public static byte[] encodeBase64​(byte[] binaryData,
                                  boolean isChunked,
                                  boolean urlSafe,
                                  int maxResultSize)
        Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
        Parameters:
        binaryData - Array containing binary data to encode.
        isChunked - if true this encoder will chunk the base64 output into 76 character blocks
        urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters.
        maxResultSize - The maximum result size to accept.
        Returns:
        Base64-encoded data.
        Throws:
        IllegalArgumentException - Thrown when the input array needs an output array bigger than maxResultSize
        Since:
        1.4

      • decodeBase64

        public static byte[] decodeBase64​(byte[] base64Data)
        Decodes Base64 data into octets
        Parameters:
        base64Data - Byte array containing Base64 data
        Returns:
        Array containing decoded data.

      • isInAlphabet

        protected boolean isInAlphabet​(byte octet)
        Returns whether or not the octet is in the Base32 alphabet.
        Parameters:
        octet - The value to test
        Returns:
        true if the value is defined in the the Base32 alphabet false otherwise.