org.apache.hadoop.hbase.util.Base64 Maven / Gradle / Ivy
/**
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.util;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FilterInputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* 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:
*
* - The default is RFC3548 format.
* - Using Base64.URLSAFE generates URL and file name friendly format as
* described in Section 4 of RFC3548.
* http://www.faqs.org/rfcs/rfc3548.html
* - Using Base64.ORDERED 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.
*
* author: Robert Harder, [email protected]
*
* version: 2.2.1
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
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 ******** */
private static final Log LOG = LogFactory.getLog(Base64.class);
/** 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";
private final static byte WHITE_SPACE_ENC = -5; // Indicates white space
private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign
/* ******** 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. */
/*
* Host platform may 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, Newline
-9, -9, // Decimal 11 - 12
-5, // Whitespace: 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 - 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' - 'N'
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' - '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' - 'm'
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' -'z'
-9, -9, -9, -9 // Decimal 123 - 126
};
/* ******** 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, Newline
-9, -9, // Decimal 11 - 12
-5, // Whitespace: 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 43
-9, // Decimal 44
62, // Minus sign at 45
-9, // Decimal 46
-9, // Slash at 47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers 0 - 9
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at 61
-9, -9, -9, // Decimal 62 - 64
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' - 'N'
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' - 'Z'
-9, -9, -9, -9, // Decimal 91 - 94
63, // Underscore at 95
-9, // Decimal 96
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' - 'm'
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' - 'z'
-9, -9, -9, -9 // Decimal 123 - 126
};
/* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */
/**
* In addition to being URL and file name friendly, this encoding preserves
* the sort order of encoded values. Whatever is input, be it string or
* just an array of bytes, when you use this encoding, the encoded value sorts
* exactly the same as the input value. It is described in the RFC change
* request:
* http://www.faqs.org/qa/rfcc-1940.html.
*
* It replaces "plus" and "slash" with "hyphen" and "underscore" and
* rearranges the alphabet so that the characters are in their natural sort
* order.
*/
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, Newline
-9, -9, // Decimal 11 - 12
-5, // Whitespace: 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 43
-9, // Decimal 44
0, // Minus sign at 45
-9, // Decimal 46
-9, // Slash at decimal 47
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers 0 - 9
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at 61
-9, -9, -9, // Decimal 62 - 64
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A' - 'M'
24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N' - 'Z'
-9, -9, -9, -9, // Decimal 91 - 94
37, // Underscore at 95
-9, // Decimal 96
38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a' - 'm'
51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n' - 'z'
-9, -9, -9, -9 // Decimal 123 - 126
};
/* ******** 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.
*
* @param options URL_SAFE or ORDERED
* @return alphabet array to use
*/
protected 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.
* @param options URL_SAFE or ORDERED
* @return alphabet array to use
*/
protected 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 getDecodabet
/** Defeats instantiation. */
private Base64() {}
/**
* Main program. Used for testing.
*
* Encodes or decodes two files from the command line
*
* @param args command arguments
*/
public static void main(String[] args) {
if (args.length < 3) {
usage("Not enough arguments.");
} else {
String flag = args[0];
String infile = args[1];
String outfile = args[2];
if (flag.equals("-e")) { // encode
encodeFileToFile(infile, outfile);
} else if (flag.equals("-d")) { // decode
decodeFileToFile(infile, outfile);
} else {
usage("Unknown flag: " + flag);
}
}
} // end main
/**
* Prints command line usage.
*
* @param msg A message to include with usage info.
*/
private 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
* @param options options for get alphabet
* @return four byte array in Base64 notation.
* @since 1.5.1
*/
protected 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
* @param options options for get alphabet
* @return the destination array
* @since 1.3
*/
protected 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(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
* @see Base64#GZIP
* @see Base64#DONT_BREAK_LINES
* @return The Base64-encoded object
* @since 2.0
*/
@SuppressWarnings({"ConstantConditions"})
public static String encodeObject(Serializable serializableObject,
int options) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
OutputStream b64os = null;
ObjectOutputStream oos = null;
try {
// ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
b64os = new Base64OutputStream(baos, ENCODE | options);
oos = ((options & GZIP) == GZIP) ?
new ObjectOutputStream(new GZIPOutputStream(b64os)) :
new ObjectOutputStream(b64os);
oos.writeObject(serializableObject);
return new String(baos.toByteArray(), PREFERRED_ENCODING);
} catch (UnsupportedEncodingException uue) {
return new String(baos.toByteArray(), StandardCharsets.UTF_8);
} catch (IOException e) {
LOG.error("error encoding object", e);
return null;
} finally {
if (oos != null) {
try {
oos.close();
} catch (Exception e) {
LOG.error("error closing ObjectOutputStream", e);
}
}
if (b64os != null) {
try {
b64os.close();
} catch (Exception e) {
LOG.error("error closing Base64OutputStream", e);
}
}
try {
baos.close();
} catch (Exception e) {
LOG.error("error closing ByteArrayOutputStream", e);
}
} // end finally
} // end encode
/**
* Encodes a byte array into Base64 notation. Does not GZip-compress data.
*
* @param source The data to convert
* @return encoded byte array
* @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
* @see Base64#URL_SAFE
* @see Base64#ORDERED
* @return encoded byte array
* @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
* @return encoded byte array
* @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
* @see Base64#GZIP
* @see Base64#DONT_BREAK_LINES
* @see Base64#URL_SAFE
* @see Base64#ORDERED
* @return encoded byte array
* @since 2.0
*/
public static String encodeBytes(byte[] source, int off, int len, int options) {
if ((options & GZIP) == GZIP) { // Compress?
// GZip -> Base64 -> ByteArray
ByteArrayOutputStream baos = new ByteArrayOutputStream();
GZIPOutputStream gzos = null;
try {
gzos =
new GZIPOutputStream(new Base64OutputStream(baos, ENCODE | options));
gzos.write(source, off, len);
gzos.close();
gzos = null;
return new String(baos.toByteArray(), PREFERRED_ENCODING);
} catch (UnsupportedEncodingException uue) {
return new String(baos.toByteArray(), StandardCharsets.UTF_8);
} catch (IOException e) {
LOG.error("error encoding byte array", e);
return null;
} finally {
if (gzos != null) {
try {
gzos.close();
} catch (Exception e) {
LOG.error("error closing GZIPOutputStream", e);
}
}
try {
baos.close();
} catch (Exception e) {
LOG.error("error closing ByteArrayOutputStream", e);
}
} // end finally
} // end Compress
// Don't compress. Better not to use streams at all then.
boolean breakLines = ((options & DONT_BREAK_LINES) == 0);
int len43 = len * 4 / 3;
byte[] outBuff =
new byte[(len43) // Main 4:3
+ ((len % 3) > 0 ? 4 : 0) // 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
} // end for: 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);
} catch (UnsupportedEncodingException uue) {
return new String(outBuff, 0, e, StandardCharsets.UTF_8);
}
} // 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 options for getDecoabet
* @see Base64#URL_SAFE
* @see Base64#ORDERED
* @return the number of decoded bytes converted
* @since 1.3
*/
@SuppressWarnings({"ConstantConditions"})
protected static int decode4to3(byte[] source, int srcOffset,
byte[] destination, int destOffset, int options) {
byte[] DECODABET = getDecodabet(options);
if (source[srcOffset + 2] == EQUALS_SIGN) { // Example: Dk==
// 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;
} else if (source[srcOffset + 3] == EQUALS_SIGN) { // Example: DkL=
// 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;
} else { // Example: DkLE
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) {
LOG.error("error decoding bytes at " + source[srcOffset] + ": " +
(DECODABET[source[srcOffset]]) + ", " + source[srcOffset + 1] +
": " + (DECODABET[source[srcOffset + 1]]) + ", " +
source[srcOffset + 2] + ": " + (DECODABET[source[srcOffset + 2]]) +
", " + source[srcOffset + 3] + ": " +
(DECODABET[source[srcOffset + 3]]), e);
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
* @param options options for getDecodabet
* @see Base64#URL_SAFE
* @see Base64#ORDERED
* @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;
byte sbiCrop;
byte sbiDecode;
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) { // Whitespace, Equals or better
if (sbiDecode >= EQUALS_SIGN_ENC) { // Equals or better
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
} else {
LOG.error("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 options for decode
* @see Base64#URL_SAFE
* @see Base64#ORDERED
* @return the decoded data
* @since 1.4
*/
public static byte[] decode(String s, int options) {
byte[] bytes;
try {
bytes = s.getBytes(PREFERRED_ENCODING);
} catch (UnsupportedEncodingException uee) {
bytes = s.getBytes(StandardCharsets.UTF_8);
} // 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 = (bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
if (GZIPInputStream.GZIP_MAGIC == head) {
GZIPInputStream gzis = null;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
gzis = new GZIPInputStream(new ByteArrayInputStream(bytes));
byte[] buffer = new byte[2048];
for (int length; (length = gzis.read(buffer)) >= 0; ) {
baos.write(buffer, 0, length);
} // end while: reading input
// No error? Get new bytes.
bytes = baos.toByteArray();
} catch (IOException e) {
// Just return originally-decoded bytes
} finally {
try {
baos.close();
} catch (Exception e) {
LOG.error("error closing ByteArrayOutputStream", e);
}
if (gzis != null) {
try {
gzis.close();
} catch (Exception e) {
LOG.error("error closing GZIPInputStream", 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);
Object obj = null;
ObjectInputStream ois = null;
try {
ois = new ObjectInputStream(new ByteArrayInputStream(objBytes));
obj = ois.readObject();
} catch (IOException e) {
LOG.error("error decoding object", e);
} catch (ClassNotFoundException e) {
LOG.error("error decoding object", e);
} finally {
if (ois != null) {
try {
ois.close();
} catch (Exception e) {
LOG.error("error closing ObjectInputStream", 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;
Base64OutputStream bos = null;
try {
bos = new Base64OutputStream(new FileOutputStream(filename), ENCODE);
bos.write(dataToEncode);
success = true;
} catch (IOException e) {
LOG.error("error encoding file: " + filename, e);
success = false;
} finally {
if (bos != null) {
try {
bos.close();
} catch (Exception e) {
LOG.error("error closing Base64OutputStream", 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;
Base64OutputStream bos = null;
try {
bos = new Base64OutputStream(new FileOutputStream(filename), DECODE);
bos.write(dataToDecode.getBytes(PREFERRED_ENCODING));
success = true;
} catch (IOException e) {
LOG.error("error decoding to file: " + filename, e);
success = false;
} finally {
if (bos != null) {
try {
bos.close();
} catch (Exception e) {
LOG.error("error closing Base64OutputStream", 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;
BufferedInputStream bufferedInputStream = null;
FileInputStream fileInputStream = null;
Base64InputStream base64InputStream = null;
try {
File file = new File(filename);
byte[] buffer;
// Check the size of file
if (file.length() > Integer.MAX_VALUE) {
LOG.fatal("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
fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
base64InputStream = new Base64InputStream(bufferedInputStream, DECODE);
// Read until done
int length = 0;
for (int numBytes; (numBytes = base64InputStream.read(buffer, length, 4096)) >= 0; ) {
length += numBytes;
}
// Save in a variable to return
decodedData = new byte[length];
System.arraycopy(buffer, 0, decodedData, 0, length);
} catch (IOException e) {
LOG.error("Error decoding from file " + filename, e);
} finally {
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (Exception e) {
LOG.error("error closing FileInputStream", e);
}
}
if (bufferedInputStream != null) {
try {
bufferedInputStream.close();
} catch (Exception e) {
LOG.error("error closing BufferedInputStream", e);
}
}
if (base64InputStream != null) {
try {
base64InputStream.close();
} catch (Exception e) {
LOG.error("error closing Base64InputStream", 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;
FileInputStream fileInputStream = null;
BufferedInputStream bufferedInputStream = null;
Base64InputStream base64InputStream = null;
try {
File file = new File(filename);
// Need max() for math on small files (v2.2.1)
byte[] buffer = new byte[Math.max((int) (file.length() * 1.4), 40)];
// Open a stream
fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
base64InputStream = new Base64InputStream(bufferedInputStream, ENCODE);
// Read until done
int length = 0;
for (int numBytes; (numBytes = base64InputStream.read(buffer, length, 4096)) >= 0; ) {
length += numBytes;
}
// Save in a variable to return
encodedData = new String(buffer, 0, length, PREFERRED_ENCODING);
} catch (IOException e) {
LOG.error("Error encoding from file " + filename, e);
} finally {
// Can't leak exceptions but still need to clean things up.
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (Exception e) {
LOG.error("error closing FileInputStream", e);
}
}
if (bufferedInputStream != null) {
try {
bufferedInputStream.close();
} catch (Exception e) {
LOG.error("error closing BufferedInputStream", e);
}
}
if (base64InputStream != null) {
try {
base64InputStream.close();
} catch (Exception e) {
LOG.error("error closing Base64InputStream", 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 = encodeFromFile(infile);
OutputStream out = null;
try {
out = new BufferedOutputStream(new FileOutputStream(outfile));
out.write(encoded.getBytes("US-ASCII")); // Strict, 7-bit output.
} catch (IOException e) {
LOG.error("error encoding from file " + infile + " to " + outfile, e);
} finally {
if (out != null) {
try {
out.close();
} catch (Exception e) {
LOG.error("error closing " + outfile, e);
}
}
} // 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 = decodeFromFile(infile);
OutputStream out = null;
try {
out = new BufferedOutputStream(new FileOutputStream(outfile));
out.write(decoded);
} catch (IOException e) {
LOG.error("error decoding from file " + infile + " to " + outfile, e);
} finally {
if (out != null) {
try {
out.close();
} catch (Exception e) {
LOG.error("error closing " + outfile, e);
}
}
} // 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.Base64InputStream} will read data from another
* InputStream, given in the constructor, and
* encode/decode to/from Base64 notation on the fly.
*
* @see Base64
* @since 1.3
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public static class Base64InputStream extends FilterInputStream {
private boolean encode; // Encoding or decoding
private int position; // Current position in the buffer
private byte[] buffer; // Buffer holding converted data
private int bufferLength; // Length of buffer (3 or 4)
private int numSigBytes; // Meaningful bytes in the buffer
private int lineLength;
private boolean breakLines; // Break lines at < 80 characters
private int options; // Record options
private byte[] decodabet; // Local copy avoids method calls
/**
* Constructs a {@link Base64InputStream} in DECODE mode.
*
* @param in the InputStream from which to read data.
* @since 1.3
*/
public Base64InputStream(InputStream in) {
this(in, DECODE);
} // end constructor
/**
* Constructs a {@link Base64.Base64InputStream} 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.Base64InputStream( in, Base64.DECODE )
*
*
* @param in the 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 Base64InputStream(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.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
*/
@Override
public int read() throws 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
} catch (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;
} else {
return -1;
} // end else
} else {
byte[] b4 = new byte[4];
int i;
for (i = 0; i < 4; i++) {
// Read four "meaningful" bytes:
int b;
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;
} else if (i == 0) {
return -1;
} else {
// Must have broken out from above.
throw new 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';
}
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.
}
// When JDK1.4 is more accepted, use an assertion here.
throw new IOException("Error in Base64 code reading stream.");
} // 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
*/
@Override
public int read(byte[] dest, int off, int len) throws IOException {
int i;
int b;
for (i = 0; i < len; i++) {
b = read();
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.Base64OutputStream} will write data to another
* OutputStream, given in the constructor, and
* encode/decode to/from Base64 notation on the fly.
*
* @see Base64
* @since 1.3
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public static class Base64OutputStream extends 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[] decodabet; // Local copy avoids method calls
/**
* Constructs a {@link Base64OutputStream} in ENCODE mode.
*
* @param out the OutputStream to which data will be written.
* @since 1.3
*/
public Base64OutputStream(OutputStream out) {
this(out, ENCODE);
} // end constructor
/**
* Constructs a {@link Base64OutputStream} 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.Base64OutputStream( out, Base64.ENCODE )
*
* @param out the 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
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public Base64OutputStream(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.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
*/
@Override
public void write(int theByte) throws 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
} else {
// Meaningful Base64 character?
if (decodabet[theByte & 0x7f] > WHITE_SPACE_ENC) {
buffer[position++] = (byte) theByte;
if (position >= bufferLength) { // Enough to output.
int len = decode4to3(buffer, 0, b4, 0, options);
out.write(b4, 0, len);
position = 0;
} // end if: enough to output
} else if (decodabet[theByte & 0x7f] != WHITE_SPACE_ENC) {
throw new 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
*/
@Override
public void write(byte[] theBytes, int off, int len) throws 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.
*
* @throws IOException e
*/
public void flushBase64() throws IOException {
if (position > 0) {
if (encode) {
out.write(encode3to4(b4, buffer, position, options));
position = 0;
} else {
throw new 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
*/
@Override
public void close() throws 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.
*
* @throws IOException e
* @since 1.5.1
*/
public void suspendEncoding() throws 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