package org.jivesoftware.smackx.filetransfer; /** * Encodes and decodes to and from Base64 notation.

Change Log: *

* *

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 rob@iharder.net * @version 2.1 */ 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; /* ******** 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"; /** * The 64 valid Base64 values. */ private final static byte[] ALPHABET; private final static byte[] _NATIVE_ALPHABET = /* * May be something funny * like EBCDIC */ { (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) '/' }; /** Determine which ALPHABET to use. */ static { byte[] __bytes; try { __bytes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" .getBytes(PREFERRED_ENCODING); } // end try catch (java.io.UnsupportedEncodingException use) { __bytes = _NATIVE_ALPHABET; // Fall back to native encoding } // end catch ALPHABET = __bytes; } // end static /** * Translates a Base64 value to either its 6-bit reconstruction value or a * negative number indicating some other meaning. */ private final static byte[] 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 */ }; // 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 /** * Defeats instantiation. */ private Base64() { } /* ******** 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) { encode3to4(threeBytes, 0, numSigBytes, b4, 0); 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. * * @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) { // 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
	 *      <i>Note: Technically, this makes your encoding non-compliant.</i>
	 *
* *

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 | dontBreakLines); // 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
	 *      <i>Note: Technically, this makes your encoding non-compliant.</i>
	 *
* *

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
	 *      <i>Note: Technically, this makes your encoding non-compliant.</i>
	 *
* *

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 * @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 | dontBreakLines); 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); 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); 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. * * @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 * @return the number of decoded bytes converted * @since 1.3 */ private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset) { // 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; } // e nd 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 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); 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) { 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); // 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[(int) (file.length() * 1.4)]; 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 /* ******** 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 /** * 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)
		 *      <i>Note: Technically, this makes your encoding non-compliant.</i>
		 *
* *

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; } // 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); 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); 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; /** * 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)
		 *      <i>Note: Technically, this makes your encoding non-compliant.</i>
		 *
* *

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]; } // 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)); 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); 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)); 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