Base64

功能:

Encodes and decodes to and from Base64 notation.

源码:

/**
 * 

* 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. *
    3. 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
    4. *
    5. 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
    6. *
    * 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. *

* * @author Robert Harder * @author [email protected] * @version 2.2.1 */ public class Base64 { /* ******** P U B L I C F I E L D S ******** */ /** No options specified. Value is zero. */ public final static int NO_OPTIONS = 0; /** Specify encoding. */ public final static int ENCODE = 1; /** Specify decoding. */ public final static int DECODE = 0; /** Specify that data should be gzip-compressed. */ public final static int GZIP = 2; /** Don't break lines when encoding (violates strict Base64 specification) */ public final static int DONT_BREAK_LINES = 8; /** * 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. */ public final static int URL_SAFE = 16; /** * Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc- * 1940.html. */ public final static int ORDERED = 32; /* ******** P R I V A T E F I E L D S ******** */ /** Maximum line length (76) of Base64 output. */ private final static int MAX_LINE_LENGTH = 76; /** The equals sign (=) as a byte. */ private final static byte EQUALS_SIGN = (byte) '='; /** The new line character (\n) as a byte. */ private final static byte NEW_LINE = (byte) '\n'; /** Preferred encoding. */ private final static String PREFERRED_ENCODING = "UTF-8"; // I think I end up not using the BAD_ENCODING indicator. // private final static byte BAD_ENCODING = -9; // Indicates error in // encoding private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in // encoding private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in // encoding /* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */ /** The 64 valid Base64 values. */ // private final static byte[] ALPHABET; /* * Host platform me be something funny like EBCDIC, so we hardcode these * values. */ private final static byte[] _STANDARD_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) '+', (byte) '/' }; /** * Translates a Base64 value to either its 6-bit reconstruction value or a * negative number indicating some other meaning. **/ private final static byte[] _STANDARD_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8 -5, -5, // Whitespace: Tab and Linefeed -9, -9, // Decimal 11 - 12 -5, // Whitespace: Carriage Return -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - // 26 -9, -9, -9, -9, -9, // Decimal 27 - 31 -5, // Whitespace: Space -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 62, // Plus sign at decimal 43 -9, -9, -9, // Decimal 44 - 46 63, // Slash at decimal 47 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine -9, -9, -9, // Decimal 58 - 60 -1, // Equals sign at decimal 61 -9, -9, -9, // Decimal 62 - 64 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through // 'N' 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' // through 'Z' -9, -9, -9, -9, -9, -9, // Decimal 91 - 96 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' // through 'm' 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' // through 'z' -9, -9, -9, -9 // Decimal 123 - 126 /* * ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 127 - 139 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255 */ }; /* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */ /** * Used in the URL- and Filename-safe dialect described in Section 4 of * RFC3548: http://www.faqs.org * /rfcs/rfc3548.html. Notice that the last two bytes become "hyphen" * and "underscore" instead of "plus" and "slash." */ private final static byte[] _URL_SAFE_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) '-', (byte) '_' }; /** * Used in decoding URL- and Filename-safe dialects of Base64. */ private final static byte[] _URL_SAFE_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8 -5, -5, // Whitespace: Tab and Linefeed -9, -9, // Decimal 11 - 12 -5, // Whitespace: Carriage Return -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - // 26 -9, -9, -9, -9, -9, // Decimal 27 - 31 -5, // Whitespace: Space -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 -9, // Plus sign at decimal 43 -9, // Decimal 44 62, // Minus sign at decimal 45 -9, // Decimal 46 -9, // Slash at decimal 47 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine -9, -9, -9, // Decimal 58 - 60 -1, // Equals sign at decimal 61 -9, -9, -9, // Decimal 62 - 64 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through // 'N' 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' // through 'Z' -9, -9, -9, -9, // Decimal 91 - 94 63, // Underscore at decimal 95 -9, // Decimal 96 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' // through 'm' 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' // through 'z' -9, -9, -9, -9 // Decimal 123 - 126 /* * ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 127 - 139 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255 */ }; /* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */ /** * I don't get the point of this technique, but it is described here: http://www.faqs.org/qa/rfcc- * 1940.html. */ private final static byte[] _ORDERED_ALPHABET = { (byte) '-', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) '_', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z' }; /** * Used in decoding the "ordered" dialect of Base64. */ private final static byte[] _ORDERED_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8 -5, -5, // Whitespace: Tab and Linefeed -9, -9, // Decimal 11 - 12 -5, // Whitespace: Carriage Return -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - // 26 -9, -9, -9, -9, -9, // Decimal 27 - 31 -5, // Whitespace: Space -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 -9, // Plus sign at decimal 43 -9, // Decimal 44 0, // Minus sign at decimal 45 -9, // Decimal 46 -9, // Slash at decimal 47 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine -9, -9, -9, // Decimal 58 - 60 -1, // Equals sign at decimal 61 -9, -9, -9, // Decimal 62 - 64 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A' // through 'M' 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N' // through 'Z' -9, -9, -9, -9, // Decimal 91 - 94 37, // Underscore at decimal 95 -9, // Decimal 96 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a' // through 'm' 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n' // through 'z' -9, -9, -9, -9 // Decimal 123 - 126 /* * ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 127 - 139 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255 */ }; /* ******** D E T E R M I N E W H I C H A L H A B E T ******** */ /** * Returns one of the _SOMETHING_ALPHABET byte arrays depending on the * options specified. It's possible, though silly, to specify ORDERED and * URLSAFE in which case one of them will be picked, though there is no * guarantee as to which one will be picked. */ private final static byte[] getAlphabet(int options) { if ((options & URL_SAFE) == URL_SAFE) return _URL_SAFE_ALPHABET; else if ((options & ORDERED) == ORDERED) return _ORDERED_ALPHABET; else return _STANDARD_ALPHABET; } // end getAlphabet /** * Returns one of the _SOMETHING_DECODABET byte arrays depending on the * options specified. It's possible, though silly, to specify ORDERED and * URL_SAFE in which case one of them will be picked, though there is no * guarantee as to which one will be picked. */ private final static byte[] getDecodabet(int options) { if ((options & URL_SAFE) == URL_SAFE) return _URL_SAFE_DECODABET; else if ((options & ORDERED) == ORDERED) return _ORDERED_DECODABET; else return _STANDARD_DECODABET; } // end getAlphabet /** Defeats instantiation. */ private Base64() { } /** * 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. */ public final static void main(String[] args) { if (args.length < 3) { usage("Not enough arguments."); } // end if: args.length < 3 else { String flag = args[0]; String infile = args[1]; String outfile = args[2]; if (flag.equals("-e")) { Base64.encodeFileToFile(infile, outfile); } // end if: encode else if (flag.equals("-d")) { Base64.decodeFileToFile(infile, outfile); } // end else if: decode else { usage("Unknown flag: " + flag); } // end else } // end else } // end main /** * Prints command line usage. * * @param msg * A message to include with usage info. */ private final static void usage(String msg) { System.err.println(msg); System.err.println("Usage: java Base64 -e|-d inputfile outputfile"); } // end usage /* ******** E N C O D I N G M E T H O D S ******** */ /** * Encodes up to the first three bytes of array threeBytes and * returns a four-byte array in Base64 notation. The actual number of * significant bytes in your array is given by numSigBytes. The * array threeBytes needs only be as big as * numSigBytes. Code can reuse a byte array by passing a * four-byte array as b4. * * @param b4 * A reusable byte array to reduce array instantiation * @param threeBytes * the array to convert * @param numSigBytes * the number of significant bytes in your array * @return four byte array in Base64 notation. * @since 1.5.1 */ private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options) { encode3to4(threeBytes, 0, numSigBytes, b4, 0, options); return b4; } // end encode3to4 /** *

* Encodes up to three bytes of the array source and writes the * resulting four Base64 bytes to destination. The source and * destination arrays can be manipulated anywhere along their length by * specifying srcOffset and destOffset. This method * does not check to make sure your arrays are large enough to accomodate * srcOffset + 3 for the source array or * destOffset + 4 for the destination array. The * actual number of significant bytes in your array is given by * numSigBytes. *

*

* This is the lowest level of the encoding methods with all possible * parameters. *

* * @param source * the array to convert * @param srcOffset * the index where conversion begins * @param numSigBytes * the number of significant bytes in your array * @param destination * the array to hold the conversion * @param destOffset * the index where output will be put * @return the destination array * @since 1.3 */ private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset, int options) { byte[] ALPHABET = getAlphabet(options); // 1 2 3 // 01234567890123456789012345678901 Bit position // --------000000001111111122222222 Array position from threeBytes // --------| || || || | Six bit groups to index ALPHABET // >>18 >>12 >> 6 >> 0 Right shift necessary // 0x3f 0x3f 0x3f Additional AND // Create buffer with zero-padding if there are only one or two // significant bytes passed in the array. // We have to shift left 24 in order to flush out the 1's that appear // when Java treats a value as negative that is cast from a byte to an // int. int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0) | (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0) | (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0); switch (numSigBytes) { case 3: destination[destOffset] = ALPHABET[(inBuff >>> 18)]; destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f]; destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f]; return destination; case 2: destination[destOffset] = ALPHABET[(inBuff >>> 18)]; destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f]; destination[destOffset + 3] = EQUALS_SIGN; return destination; case 1: destination[destOffset] = ALPHABET[(inBuff >>> 18)]; destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; destination[destOffset + 2] = EQUALS_SIGN; destination[destOffset + 3] = EQUALS_SIGN; return destination; default: return destination; } // end switch } // end encode3to4 /** * 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. * * @param serializableObject * The object to encode * @return The Base64-encoded object * @since 1.4 */ public static String encodeObject(java.io.Serializable serializableObject) { return encodeObject(serializableObject, NO_OPTIONS); } // end encodeObject /** * 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 ) * * @param serializableObject * The object to encode * @param options * Specified options * @return The Base64-encoded object * @see Base64#GZIP * @see Base64#DONT_BREAK_LINES * @since 2.0 */ public static String encodeObject(java.io.Serializable serializableObject, int options) { // Streams java.io.ByteArrayOutputStream baos = null; java.io.OutputStream b64os = null; java.io.ObjectOutputStream oos = null; java.util.zip.GZIPOutputStream gzos = null; // Isolate options int gzip = (options & GZIP); int dontBreakLines = (options & DONT_BREAK_LINES); try { // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream baos = new java.io.ByteArrayOutputStream(); b64os = new Base64.OutputStream(baos, ENCODE | options); // GZip? if (gzip == GZIP) { gzos = new java.util.zip.GZIPOutputStream(b64os); oos = new java.io.ObjectOutputStream(gzos); } // end if: gzip else oos = new java.io.ObjectOutputStream(b64os); oos.writeObject(serializableObject); } // end try catch (java.io.IOException e) { e.printStackTrace(); return null; } // end catch finally { try { oos.close(); } catch (Exception e) { } try { gzos.close(); } catch (Exception e) { } try { b64os.close(); } catch (Exception e) { } try { baos.close(); } catch (Exception e) { } } // end finally // Return value according to relevant encoding. try { return new String(baos.toByteArray(), PREFERRED_ENCODING); } // end try catch (java.io.UnsupportedEncodingException uue) { return new String(baos.toByteArray()); } // end catch } // end encode /** * Encodes a byte array into Base64 notation. Does not GZip-compress data. * * @param source * The data to convert * @since 1.4 */ public static String encodeBytes(byte[] source) { return encodeBytes(source, 0, source.length, NO_OPTIONS); } // end encodeBytes /** * 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 ) * * * @param source * The data to convert * @param options * Specified options * @see Base64#GZIP * @see Base64#DONT_BREAK_LINES * @since 2.0 */ public static String encodeBytes(byte[] source, int options) { return encodeBytes(source, 0, source.length, options); } // end encodeBytes /** * Encodes a byte array into Base64 notation. Does not GZip-compress data. * * @param source * The data to convert * @param off * Offset in array where conversion should begin * @param len * Length of data to convert * @since 1.4 */ public static String encodeBytes(byte[] source, int off, int len) { return encodeBytes(source, off, len, NO_OPTIONS); } // end encodeBytes /** * 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 ) * * * @param source * The data to convert * @param off * Offset in array where conversion should begin * @param len * Length of data to convert * @param options * Specified options; alphabet type is pulled from this * (standard, url-safe, ordered) * @see Base64#GZIP * @see Base64#DONT_BREAK_LINES * @since 2.0 */ public static String encodeBytes(byte[] source, int off, int len, int options) { // Isolate options int dontBreakLines = (options & DONT_BREAK_LINES); int gzip = (options & GZIP); // Compress? if (gzip == GZIP) { java.io.ByteArrayOutputStream baos = null; java.util.zip.GZIPOutputStream gzos = null; Base64.OutputStream b64os = null; try { // GZip -> Base64 -> ByteArray baos = new java.io.ByteArrayOutputStream(); b64os = new Base64.OutputStream(baos, ENCODE | options); gzos = new java.util.zip.GZIPOutputStream(b64os); gzos.write(source, off, len); gzos.close(); } // end try catch (java.io.IOException e) { e.printStackTrace(); return null; } // end catch finally { try { gzos.close(); } catch (Exception e) { } try { b64os.close(); } catch (Exception e) { } try { baos.close(); } catch (Exception e) { } } // end finally // Return value according to relevant encoding. try { return new String(baos.toByteArray(), PREFERRED_ENCODING); } // end try catch (java.io.UnsupportedEncodingException uue) { return new String(baos.toByteArray()); } // end catch } // end if: compress // Else, don't compress. Better not to use streams at all then. else { // Convert option to boolean in way that code likes it. boolean breakLines = dontBreakLines == 0; int len43 = len * 4 / 3; byte[] outBuff = new byte[(len43) // Main 4:3 + ((len % 3) > 0 ? 4 : 0) // Account for padding + (breakLines ? (len43 / MAX_LINE_LENGTH) : 0)]; // New // lines int d = 0; int e = 0; int len2 = len - 2; int lineLength = 0; for (; d < len2; d += 3, e += 4) { encode3to4(source, d + off, 3, outBuff, e, options); lineLength += 4; if (breakLines && lineLength == MAX_LINE_LENGTH) { outBuff[e + 4] = NEW_LINE; e++; lineLength = 0; } // end if: end of line } // en dfor: each piece of array if (d < len) { encode3to4(source, d + off, len - d, outBuff, e, options); e += 4; } // end if: some padding needed // Return value according to relevant encoding. try { return new String(outBuff, 0, e, PREFERRED_ENCODING); } // end try catch (java.io.UnsupportedEncodingException uue) { return new String(outBuff, 0, e); } // end catch } // end else: don't compress } // end encodeBytes /* ******** D E C O D I N G M E T H O D S ******** */ /** * Decodes four bytes from array source and writes the resulting * bytes (up to three of them) to destination. The source and * destination arrays can be manipulated anywhere along their length by * specifying srcOffset and destOffset. This method * does not check to make sure your arrays are large enough to accomodate * srcOffset + 4 for the source array or * destOffset + 3 for the destination array. This * method returns the actual number of bytes that were converted from the * Base64 encoding. *

* This is the lowest level of the decoding methods with all possible * parameters. *

* * * @param source * the array to convert * @param srcOffset * the index where conversion begins * @param destination * the array to hold the conversion * @param destOffset * the index where output will be put * @param options * alphabet type is pulled from this (standard, url-safe, * ordered) * @return the number of decoded bytes converted * @since 1.3 */ private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options) { byte[] DECODABET = getDecodabet(options); // Example: Dk== if (source[srcOffset + 2] == EQUALS_SIGN) { // Two ways to do the same thing. Don't know which way I like best. // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 // ) // | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 ); int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12); destination[destOffset] = (byte) (outBuff >>> 16); return 1; } // Example: DkL= else if (source[srcOffset + 3] == EQUALS_SIGN) { // Two ways to do the same thing. Don't know which way I like best. // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 // ) // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 ) // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 ); int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12) | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6); destination[destOffset] = (byte) (outBuff >>> 16); destination[destOffset + 1] = (byte) (outBuff >>> 8); return 2; } // Example: DkLE else { try { // Two ways to do the same thing. Don't know which way I like // best. // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) // >>> 6 ) // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 ) // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 ) // | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 ); int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12) | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6) | ((DECODABET[source[srcOffset + 3]] & 0xFF)); destination[destOffset] = (byte) (outBuff >> 16); destination[destOffset + 1] = (byte) (outBuff >> 8); destination[destOffset + 2] = (byte) (outBuff); return 3; } catch (Exception e) { System.out.println("" + source[srcOffset] + ": " + (DECODABET[source[srcOffset]])); System.out.println("" + source[srcOffset + 1] + ": " + (DECODABET[source[srcOffset + 1]])); System.out.println("" + source[srcOffset + 2] + ": " + (DECODABET[source[srcOffset + 2]])); System.out.println("" + source[srcOffset + 3] + ": " + (DECODABET[source[srcOffset + 3]])); return -1; } // end catch } } // end decodeToBytes /** * 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. * * @param source * The Base64 encoded data * @param off * The offset of where to begin decoding * @param len * The length of characters to decode * @return decoded data * @since 1.3 */ public static byte[] decode(byte[] source, int off, int len, int options) { byte[] DECODABET = getDecodabet(options); int len34 = len * 3 / 4; byte[] outBuff = new byte[len34]; // Upper limit on size of output int outBuffPosn = 0; byte[] b4 = new byte[4]; int b4Posn = 0; int i = 0; byte sbiCrop = 0; byte sbiDecode = 0; for (i = off; i < off + len; i++) { sbiCrop = (byte) (source[i] & 0x7f); // Only the low seven bits sbiDecode = DECODABET[sbiCrop]; if (sbiDecode >= WHITE_SPACE_ENC) // White space, Equals sign or // better { if (sbiDecode >= EQUALS_SIGN_ENC) { b4[b4Posn++] = sbiCrop; if (b4Posn > 3) { outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, options); b4Posn = 0; // If that was the equals sign, break out of 'for' loop if (sbiCrop == EQUALS_SIGN) break; } // end if: quartet built } // end if: equals sign or better } // end if: white space, equals sign or better else { System.err.println("Bad Base64 input character at " + i + ": " + source[i] + "(decimal)"); return null; } // end else: } // each input character byte[] out = new byte[outBuffPosn]; System.arraycopy(outBuff, 0, out, 0, outBuffPosn); return out; } // end decode /** * Decodes data from Base64 notation, automatically detecting * gzip-compressed data and decompressing it. * * @param s * the string to decode * @return the decoded data * @since 1.4 */ public static byte[] decode(String s) { return decode(s, NO_OPTIONS); } /** * Decodes data from Base64 notation, automatically detecting * gzip-compressed data and decompressing it. * * @param s * the string to decode * @param options * encode options such as URL_SAFE * @return the decoded data * @since 1.4 */ public static byte[] decode(String s, int options) { byte[] bytes; try { bytes = s.getBytes(PREFERRED_ENCODING); } // end try catch (java.io.UnsupportedEncodingException uee) { bytes = s.getBytes(); } // end catch // // Decode bytes = decode(bytes, 0, bytes.length, options); // Check to see if it's gzip-compressed // GZIP Magic Two-Byte Number: 0x8b1f (35615) if (bytes != null && bytes.length >= 4) { int head = ((int) bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00); if (java.util.zip.GZIPInputStream.GZIP_MAGIC == head) { java.io.ByteArrayInputStream bais = null; java.util.zip.GZIPInputStream gzis = null; java.io.ByteArrayOutputStream baos = null; byte[] buffer = new byte[2048]; int length = 0; try { baos = new java.io.ByteArrayOutputStream(); bais = new java.io.ByteArrayInputStream(bytes); gzis = new java.util.zip.GZIPInputStream(bais); while ((length = gzis.read(buffer)) >= 0) { baos.write(buffer, 0, length); } // end while: reading input // No error? Get new bytes. bytes = baos.toByteArray(); } // end try catch (java.io.IOException e) { // Just return originally-decoded bytes } // end catch finally { try { baos.close(); } catch (Exception e) { } try { gzis.close(); } catch (Exception e) { } try { bais.close(); } catch (Exception e) { } } // end finally } // end if: gzipped } // end if: bytes.length >= 2 return bytes; } // end decode /** * Attempts to decode Base64 data and deserialize a Java Object within. * Returns null if there was an error. * * @param encodedObject * The Base64 data to decode * @return The decoded and deserialized object * @since 1.5 */ public static Object decodeToObject(String encodedObject) { // Decode and gunzip if necessary byte[] objBytes = decode(encodedObject); java.io.ByteArrayInputStream bais = null; java.io.ObjectInputStream ois = null; Object obj = null; try { bais = new java.io.ByteArrayInputStream(objBytes); ois = new java.io.ObjectInputStream(bais); obj = ois.readObject(); } // end try catch (java.io.IOException e) { e.printStackTrace(); obj = null; } // end catch catch (java.lang.ClassNotFoundException e) { e.printStackTrace(); obj = null; } // end catch finally { try { bais.close(); } catch (Exception e) { } try { ois.close(); } catch (Exception e) { } } // end finally return obj; } // end decodeObject /** * Convenience method for encoding data to a file. * * @param dataToEncode * byte array of data to encode in base64 form * @param filename * Filename for saving encoded data * @return true if successful, false otherwise * * @since 2.1 */ public static boolean encodeToFile(byte[] dataToEncode, String filename) { boolean success = false; Base64.OutputStream bos = null; try { bos = new Base64.OutputStream( new java.io.FileOutputStream(filename), Base64.ENCODE); bos.write(dataToEncode); success = true; } // end try catch (java.io.IOException e) { success = false; } // end catch: IOException finally { try { bos.close(); } catch (Exception e) { } } // end finally return success; } // end encodeToFile /** * Convenience method for decoding data to a file. * * @param dataToDecode * Base64-encoded data as a string * @param filename * Filename for saving decoded data * @return true if successful, false otherwise * * @since 2.1 */ public static boolean decodeToFile(String dataToDecode, String filename) { boolean success = false; Base64.OutputStream bos = null; try { bos = new Base64.OutputStream( new java.io.FileOutputStream(filename), Base64.DECODE); bos.write(dataToDecode.getBytes(PREFERRED_ENCODING)); success = true; } // end try catch (java.io.IOException e) { success = false; } // end catch: IOException finally { try { bos.close(); } catch (Exception e) { } } // end finally return success; } // end decodeToFile /** * Convenience method for reading a base64-encoded file and decoding it. * * @param filename * Filename for reading encoded data * @return decoded byte array or null if unsuccessful * * @since 2.1 */ public static byte[] decodeFromFile(String filename) { byte[] decodedData = null; Base64.InputStream bis = null; try { // Set up some useful variables java.io.File file = new java.io.File(filename); byte[] buffer = null; int length = 0; int numBytes = 0; // Check for size of file if (file.length() > Integer.MAX_VALUE) { System.err .println("File is too big for this convenience method (" + file.length() + " bytes)."); return null; } // end if: file too big for int index buffer = new byte[(int) file.length()]; // Open a stream bis = new Base64.InputStream(new java.io.BufferedInputStream( new java.io.FileInputStream(file)), Base64.DECODE); // Read until done while ((numBytes = bis.read(buffer, length, 4096)) >= 0) length += numBytes; // Save in a variable to return decodedData = new byte[length]; System.arraycopy(buffer, 0, decodedData, 0, length); } // end try catch (java.io.IOException e) { System.err.println("Error decoding from file " + filename); } // end catch: IOException finally { try { bis.close(); } catch (Exception e) { } } // end finally return decodedData; } // end decodeFromFile /** * Convenience method for reading a binary file and base64-encoding it. * * @param filename * Filename for reading binary data * @return base64-encoded string or null if unsuccessful * * @since 2.1 */ public static String encodeFromFile(String filename) { String encodedData = null; Base64.InputStream bis = null; try { // Set up some useful variables java.io.File file = new java.io.File(filename); byte[] buffer = new byte[Math.max((int) (file.length() * 1.4), 40)]; // Need // max() // for // math // on // small // files // (v2.2.1) int length = 0; int numBytes = 0; // Open a stream bis = new Base64.InputStream(new java.io.BufferedInputStream( new java.io.FileInputStream(file)), Base64.ENCODE); // Read until done while ((numBytes = bis.read(buffer, length, 4096)) >= 0) length += numBytes; // Save in a variable to return encodedData = new String(buffer, 0, length, Base64.PREFERRED_ENCODING); } // end try catch (java.io.IOException e) { System.err.println("Error encoding from file " + filename); } // end catch: IOException finally { try { bis.close(); } catch (Exception e) { } } // end finally return encodedData; } // end encodeFromFile /** * Reads infile and encodes it to outfile. * * @param infile * Input file * @param outfile * Output file * @since 2.2 */ public static void encodeFileToFile(String infile, String outfile) { String encoded = Base64.encodeFromFile(infile); java.io.OutputStream out = null; try { out = new java.io.BufferedOutputStream( new java.io.FileOutputStream(outfile)); out.write(encoded.getBytes("US-ASCII")); // Strict, 7-bit output. } // end try catch (java.io.IOException ex) { ex.printStackTrace(); } // end catch finally { try { out.close(); } catch (Exception ex) { } } // end finally } // end encodeFileToFile /** * Reads infile and decodes it to outfile. * * @param infile * Input file * @param outfile * Output file * @since 2.2 */ public static void decodeFileToFile(String infile, String outfile) { byte[] decoded = Base64.decodeFromFile(infile); java.io.OutputStream out = null; try { out = new java.io.BufferedOutputStream( new java.io.FileOutputStream(outfile)); out.write(decoded); } // end try catch (java.io.IOException ex) { ex.printStackTrace(); } // end catch finally { try { out.close(); } catch (Exception ex) { } } // end finally } // end decodeFileToFile /* ******** I N N E R C L A S S I N P U T S T R E A M ******** */ /** * A {@link Base64.InputStream} will read data from another * java.io.InputStream, given in the constructor, and encode/decode * to/from Base64 notation on the fly. * * @see Base64 * @since 1.3 */ public static class InputStream extends java.io.FilterInputStream { private boolean encode; // Encoding or decoding private int position; // Current position in the buffer private byte[] buffer; // Small buffer holding converted data private int bufferLength; // Length of buffer (3 or 4) private int numSigBytes; // Number of meaningful bytes in the buffer private int lineLength; private boolean breakLines; // Break lines at less than 80 characters private int options; // Record options used to create the stream. private byte[] alphabet; // Local copies to avoid extra method calls private byte[] decodabet; // Local copies to avoid extra method calls /** * Constructs a {@link Base64.InputStream} in DECODE mode. * * @param in * the java.io.InputStream from which to read data. * @since 1.3 */ public InputStream(java.io.InputStream in) { this(in, DECODE); } // end constructor /** * Constructs a {@link Base64.InputStream} in either ENCODE or DECODE * mode. *

* Valid options: * *

         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     Note: Technically, this makes your encoding non-compliant.
         * 
*

* Example: new Base64.InputStream( in, Base64.DECODE ) * * * @param in * the java.io.InputStream from which to read data. * @param options * Specified options * @see Base64#ENCODE * @see Base64#DECODE * @see Base64#DONT_BREAK_LINES * @since 2.0 */ public InputStream(java.io.InputStream in, int options) { super(in); this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES; this.encode = (options & ENCODE) == ENCODE; this.bufferLength = encode ? 4 : 3; this.buffer = new byte[bufferLength]; this.position = -1; this.lineLength = 0; this.options = options; // Record for later, mostly to determine // which alphabet to use this.alphabet = getAlphabet(options); this.decodabet = getDecodabet(options); } // end constructor /** * Reads enough of the input stream to convert to/from Base64 and * returns the next byte. * * @return next byte * @since 1.3 */ public int read() throws java.io.IOException { // Do we need to get data? if (position < 0) { if (encode) { byte[] b3 = new byte[3]; int numBinaryBytes = 0; for (int i = 0; i < 3; i++) { try { int b = in.read(); // If end of stream, b is -1. if (b >= 0) { b3[i] = (byte) b; numBinaryBytes++; } // end if: not end of stream } // end try: read catch (java.io.IOException e) { // Only a problem if we got no data at all. if (i == 0) throw e; } // end catch } // end for: each needed input byte if (numBinaryBytes > 0) { encode3to4(b3, 0, numBinaryBytes, buffer, 0, options); position = 0; numSigBytes = 4; } // end if: got data else { return -1; } // end else } // end if: encoding // Else decoding else { byte[] b4 = new byte[4]; int i = 0; for (i = 0; i < 4; i++) { // Read four "meaningful" bytes: int b = 0; do { b = in.read(); } while (b >= 0 && decodabet[b & 0x7f] <= WHITE_SPACE_ENC); if (b < 0) break; // Reads a -1 if end of stream b4[i] = (byte) b; } // end for: each needed input byte if (i == 4) { numSigBytes = decode4to3(b4, 0, buffer, 0, options); position = 0; } // end if: got four characters else if (i == 0) { return -1; } // end else if: also padded correctly else { // Must have broken out from above. throw new java.io.IOException( "Improperly padded Base64 input."); } // end } // end else: decode } // end else: get data // Got data? if (position >= 0) { // End of relevant data? if ( /* !encode && */position >= numSigBytes) return -1; if (encode && breakLines && lineLength >= MAX_LINE_LENGTH) { lineLength = 0; return '\n'; } // end if else { lineLength++; // This isn't important when decoding // but throwing an extra "if" seems // just as wasteful. int b = buffer[position++]; if (position >= bufferLength) position = -1; return b & 0xFF; // This is how you "cast" a byte that's // intended to be unsigned. } // end else } // end if: position >= 0 // Else error else { // When JDK1.4 is more accepted, use an assertion here. throw new java.io.IOException( "Error in Base64 code reading stream."); } // end else } // end read /** * Calls {@link #read()} repeatedly until the end of stream is reached * or len bytes are read. Returns number of bytes read into * array or -1 if end of stream is encountered. * * @param dest * array to hold values * @param off * offset for array * @param len * max number of bytes to read into array * @return bytes read into array or -1 if end of stream is encountered. * @since 1.3 */ public int read(byte[] dest, int off, int len) throws java.io.IOException { int i; int b; for (i = 0; i < len; i++) { b = read(); // if( b < 0 && i == 0 ) // return -1; if (b >= 0) dest[off + i] = (byte) b; else if (i == 0) return -1; else break; // Out of 'for' loop } // end for: each byte read return i; } // end read } // end inner class InputStream /* ******** I N N E R C L A S S O U T P U T S T R E A M ******** */ /** * A {@link Base64.OutputStream} will write data to another * java.io.OutputStream, given in the constructor, and * encode/decode to/from Base64 notation on the fly. * * @see Base64 * @since 1.3 */ public static class OutputStream extends java.io.FilterOutputStream { private boolean encode; private int position; private byte[] buffer; private int bufferLength; private int lineLength; private boolean breakLines; private byte[] b4; // Scratch used in a few places private boolean suspendEncoding; private int options; // Record for later private byte[] alphabet; // Local copies to avoid extra method calls private byte[] decodabet; // Local copies to avoid extra method calls /** * Constructs a {@link Base64.OutputStream} in ENCODE mode. * * @param out * the java.io.OutputStream to which data will be * written. * @since 1.3 */ public OutputStream(java.io.OutputStream out) { this(out, ENCODE); } // end constructor /** * Constructs a {@link Base64.OutputStream} in either ENCODE or DECODE * mode. *

* Valid options: * *

         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     Note: Technically, this makes your encoding non-compliant.
         * 
*

* Example: new Base64.OutputStream( out, Base64.ENCODE ) * * @param out * the java.io.OutputStream to which data will be * written. * @param options * Specified options. * @see Base64#ENCODE * @see Base64#DECODE * @see Base64#DONT_BREAK_LINES * @since 1.3 */ public OutputStream(java.io.OutputStream out, int options) { super(out); this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES; this.encode = (options & ENCODE) == ENCODE; this.bufferLength = encode ? 3 : 4; this.buffer = new byte[bufferLength]; this.position = 0; this.lineLength = 0; this.suspendEncoding = false; this.b4 = new byte[4]; this.options = options; this.alphabet = getAlphabet(options); this.decodabet = getDecodabet(options); } // end constructor /** * Writes the byte to the output stream after converting to/from Base64 * notation. When encoding, bytes are buffered three at a time before * the output stream actually gets a write() call. When decoding, bytes * are buffered four at a time. * * @param theByte * the byte to write * @since 1.3 */ public void write(int theByte) throws java.io.IOException { // Encoding suspended? if (suspendEncoding) { super.out.write(theByte); return; } // end if: supsended // Encode? if (encode) { buffer[position++] = (byte) theByte; if (position >= bufferLength) // Enough to encode. { out.write(encode3to4(b4, buffer, bufferLength, options)); lineLength += 4; if (breakLines && lineLength >= MAX_LINE_LENGTH) { out.write(NEW_LINE); lineLength = 0; } // end if: end of line position = 0; } // end if: enough to output } // end if: encoding // Else, Decoding else { // Meaningful Base64 character? if (decodabet[theByte & 0x7f] > WHITE_SPACE_ENC) { buffer[position++] = (byte) theByte; if (position >= bufferLength) // Enough to output. { int len = Base64.decode4to3(buffer, 0, b4, 0, options); out.write(b4, 0, len); // out.write( Base64.decode4to3( buffer ) ); position = 0; } // end if: enough to output } // end if: meaningful base64 character else if (decodabet[theByte & 0x7f] != WHITE_SPACE_ENC) { throw new java.io.IOException( "Invalid character in Base64 data."); } // end else: not white space either } // end else: decoding } // end write /** * Calls {@link #write(int)} repeatedly until len bytes are * written. * * @param theBytes * array from which to read bytes * @param off * offset for array * @param len * max number of bytes to read into array * @since 1.3 */ public void write(byte[] theBytes, int off, int len) throws java.io.IOException { // Encoding suspended? if (suspendEncoding) { super.out.write(theBytes, off, len); return; } // end if: supsended for (int i = 0; i < len; i++) { write(theBytes[off + i]); } // end for: each byte written } // end write /** * Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer * without closing the stream. */ public void flushBase64() throws java.io.IOException { if (position > 0) { if (encode) { out.write(encode3to4(b4, buffer, position, options)); position = 0; } // end if: encoding else { throw new java.io.IOException( "Base64 input not properly padded."); } // end else: decoding } // end if: buffer partially full } // end flush /** * Flushes and closes (I think, in the superclass) the stream. * * @since 1.3 */ public void close() throws java.io.IOException { // 1. Ensure that pending characters are written flushBase64(); // 2. Actually close the stream // Base class both flushes and closes. super.close(); buffer = null; out = null; } // end close /** * Suspends encoding of the stream. May be helpful if you need to embed * a piece of base640-encoded data in a stream. * * @since 1.5.1 */ public void suspendEncoding() throws java.io.IOException { flushBase64(); this.suspendEncoding = true; } // end suspendEncoding /** * Resumes encoding of the stream. May be helpful if you need to embed a * piece of base640-encoded data in a stream. * * @since 1.5.1 */ public void resumeEncoding() { this.suspendEncoding = false; } // end resumeEncoding } // end inner class OutputStream } // end class Base64

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