Package psidev.psi.mi.jami.utils.checksum

Class Base64

  • public class Base64
extends Object

    Encodes and decodes to and from Base64 notation.

    Homepage: http://iharder.net/base64.

    Change Log:

    • v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when using very small files (~< 40 bytes).
    • v2.2 - Added some helper methods for encoding/decoding directly from one file to the next. Also added a main() method to support command line encoding/decoding from one file to the next. Also added these Base64 dialects:
      1. The default is RFC3548 format.
      2. Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates URL and file name friendly format as described in Section 4 of RFC3548. http://www.faqs.org/rfcs/rfc3548.html
      3. Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates URL and file name friendly format that preserves lexical ordering as described in http://www.faqs.org/qa/rfcc-1940.html
      Special thanks to Jim Kellerman at http://www.powerset.com/ for contributing the new Base64 dialects.
    • v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading and writing to and from files.
    • v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like EBCDIC).
    • v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.
    • v2.0 - I got rid of methods that used booleans to set options. Now everything is more consolidated and cleaner. The code now detects when data that's being decoded is gzip-compressed and will decompress it automatically. Generally things are cleaner. You'll probably have to change some method calls that you were making to support the new options format (ints that you "OR" together).
    • v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using decode( String s, boolean gzipCompressed ). Added the ability to "suspend" encoding in the Output Stream so you can turn on and off the encoding if you need to embed base64 data in an otherwise "normal" stream (like an XML file).
    • v1.5 - Output stream pases on flush() command but doesn't do anything itself. This helps when using GZIP streams. Added the ability to GZip-compress objects before encoding them.
    • v1.4 - Added helper methods to read/write files.
    • v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.
    • v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream where last buffer being read, if not completely full, was not returned.
    • v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.
    • v1.3.3 - Fixed I/O streams which were totally messed up.

    I am placing this code in the Public Domain. Do with it as you will. This software comes with no guarantees or warranties but with plenty of well-wishing instead! Please visit http://iharder.net/base64 periodically to check for updates or to contribute improvements.

    Version:
    $Id: $
    Author:
    jmedina

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Base64.InputStream
      A Base64.InputStream will read data from another java.io.InputStream, given in the constructor, and encode/decode to/from Base64 notation on the fly.
      static class  Base64.OutputStream
      A Base64.OutputStream will write data to another java.io.OutputStream, given in the constructor, and encode/decode to/from Base64 notation on the fly.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static byte[] decode​(byte[] source, int off, int len, int options)
      Very low-level access to decoding ASCII characters in the form of a byte array.
      static byte[] decode​(String s)
      Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
      static byte[] decode​(String s, int options)
      Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
      static void decodeFileToFile​(String infile, String outfile)
      Reads infile and decodes it to outfile.
      static byte[] decodeFromFile​(String filename)
      Convenience method for reading a base64-encoded file and decoding it.
      static boolean decodeToFile​(String dataToDecode, String filename)
      Convenience method for decoding data to a file.
      static Object decodeToObject​(String encodedObject)
      Attempts to decode Base64 data and deserialize a Java Object within.
      static String encodeBytes​(byte[] source)
      Encodes a byte array into Base64 notation.
      static String encodeBytes​(byte[] source, int options)
      Encodes a byte array into Base64 notation.
      static String encodeBytes​(byte[] source, int off, int len)
      Encodes a byte array into Base64 notation.
      static String encodeBytes​(byte[] source, int off, int len, int options)
      Encodes a byte array into Base64 notation.
      static void encodeFileToFile​(String infile, String outfile)
      Reads infile and encodes it to outfile.
      static String encodeFromFile​(String filename)
      Convenience method for reading a binary file and base64-encoding it.
      static String encodeObject​(Serializable serializableObject)
      Serializes an object and returns the Base64-encoded version of that serialized object.
      static String encodeObject​(Serializable serializableObject, int options)
      Serializes an object and returns the Base64-encoded version of that serialized object.
      static boolean encodeToFile​(byte[] dataToEncode, String filename)
      Convenience method for encoding data to a file.
      static void main​(String[] args)
      Encodes or decodes two files from the command line; feel free to delete this method (in fact you probably should) if you're embedding this code into a larger program.

    • Field Detail

      • NO_OPTIONS

        public static final int NO_OPTIONS
        No options specified. Value is zero.
        See Also:
        Constant Field Values

      • GZIP

        public static final int GZIP
        Specify that data should be gzip-compressed.
        See Also:
        Constant Field Values

      • DONT_BREAK_LINES

        public static final int DONT_BREAK_LINES
        Don't break lines when encoding (violates strict Base64 specification)
        See Also:
        Constant Field Values

      • URL_SAFE

        public static final int URL_SAFE
        Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html. It is important to note that data encoded this way is not officially valid Base64, or at the very least should not be called Base64 without also specifying that is was encoded using the URL- and Filename-safe dialect.
        See Also:
        Constant Field Values

    • Method Detail

      • main

        public static final void main​(String[] args)
        Encodes or decodes two files from the command line; feel free to delete this method (in fact you probably should) if you're embedding this code into a larger program.
        Parameters:
        args - an array of String objects.

      • encodeObject

        public static String encodeObject​(Serializable serializableObject)
        Serializes an object and returns the Base64-encoded version of that serialized object. If the object cannot be serialized or there is another error, the method will return null. The object is not GZip-compressed before being encoded.
        Parameters:
        serializableObject - The object to encode
        Returns:
        The Base64-encoded object
        Since:
        1.4

      • encodeObject

        public static String encodeObject​(Serializable serializableObject,
                                  int options)
        Serializes an object and returns the Base64-encoded version of that serialized object. If the object cannot be serialized or there is another error, the method will return null. Valid options:
           GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
        Example: encodeObject( myObj, Base64.GZIP ) or Example: encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )
        Parameters:
        serializableObject - The object to encode
        options - Specified options
        Returns:
        The Base64-encoded object
        Since:
        2.0
        See Also:
        GZIP, DONT_BREAK_LINES

      • encodeBytes

        public static String encodeBytes​(byte[] source)
        Encodes a byte array into Base64 notation. Does not GZip-compress data.
        Parameters:
        source - The data to convert
        Returns:
        a String object.
        Since:
        1.4

      • encodeBytes

        public static String encodeBytes​(byte[] source,
                                 int options)
        Encodes a byte array into Base64 notation. Valid options:
           GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
        Example: encodeBytes( myData, Base64.GZIP ) or Example: encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )
        Parameters:
        source - The data to convert
        options - Specified options
        Returns:
        a String object.
        Since:
        2.0
        See Also:
        GZIP, DONT_BREAK_LINES

      • encodeBytes

        public static String encodeBytes​(byte[] source,
                                 int off,
                                 int len)
        Encodes a byte array into Base64 notation. Does not GZip-compress data.
        Parameters:
        source - The data to convert
        off - Offset in array where conversion should begin
        len - Length of data to convert
        Returns:
        a String object.
        Since:
        1.4

      • encodeBytes

        public static String encodeBytes​(byte[] source,
                                 int off,
                                 int len,
                                 int options)
        Encodes a byte array into Base64 notation.

        Valid options:

           GZIP: gzip-compresses object before encoding it.
   DONT_BREAK_LINES: don't break lines at 76 characters
     Note: Technically, this makes your encoding non-compliant.
        Example: encodeBytes( myData, Base64.GZIP ) or Example: encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )
        Parameters:
        source - The data to convert
        off - Offset in array where conversion should begin
        len - Length of data to convert
        options - Specified options
        Returns:
        a String object.
        Since:
        2.0
        See Also:
        GZIP, DONT_BREAK_LINES

      • decode

        public static byte[] decode​(byte[] source,
                            int off,
                            int len,
                            int options)
        Very low-level access to decoding ASCII characters in the form of a byte array. Does not support automatically gunzipping or any other "fancy" features.
        Parameters:
        source - The Base64 encoded data
        off - The offset of where to begin decoding
        len - The length of characters to decode
        options - a int.
        Returns:
        decoded data
        Since:
        1.3

      • decode

        public static byte[] decode​(String s)
        Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
        Parameters:
        s - the string to decode
        Returns:
        the decoded data
        Since:
        1.4

      • decode

        public static byte[] decode​(String s,
                            int options)
        Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
        Parameters:
        s - the string to decode
        options - encode options such as URL_SAFE
        Returns:
        the decoded data
        Since:
        1.4

      • decodeToObject

        public static Object decodeToObject​(String encodedObject)
        Attempts to decode Base64 data and deserialize a Java Object within. Returns null if there was an error.
        Parameters:
        encodedObject - The Base64 data to decode
        Returns:
        The decoded and deserialized object
        Since:
        1.5

      • encodeToFile

        public static boolean encodeToFile​(byte[] dataToEncode,
                                   String filename)
        Convenience method for encoding data to a file.
        Parameters:
        dataToEncode - byte array of data to encode in base64 form
        filename - Filename for saving encoded data
        Returns:
        true if successful, false otherwise
        Since:
        2.1

      • decodeToFile

        public static boolean decodeToFile​(String dataToDecode,
                                   String filename)
        Convenience method for decoding data to a file.
        Parameters:
        dataToDecode - Base64-encoded data as a string
        filename - Filename for saving decoded data
        Returns:
        true if successful, false otherwise
        Since:
        2.1

      • decodeFromFile

        public static byte[] decodeFromFile​(String filename)
        Convenience method for reading a base64-encoded file and decoding it.
        Parameters:
        filename - Filename for reading encoded data
        Returns:
        decoded byte array or null if unsuccessful
        Since:
        2.1

      • encodeFromFile

        public static String encodeFromFile​(String filename)
        Convenience method for reading a binary file and base64-encoding it.
        Parameters:
        filename - Filename for reading binary data
        Returns:
        base64-encoded string or null if unsuccessful
        Since:
        2.1

      • encodeFileToFile

        public static void encodeFileToFile​(String infile,
                                    String outfile)
        Reads infile and encodes it to outfile.
        Parameters:
        infile - Input file
        outfile - Output file
        Since:
        2.2

      • decodeFileToFile

        public static void decodeFileToFile​(String infile,
                                    String outfile)
        Reads infile and decodes it to outfile.
        Parameters:
        infile - Input file
        outfile - Output file
        Since:
        2.2