Undertow 2.3.12.Final · io.undertow.websockets.core.protocol.version07.Base64

Encodes and decodes to and from Base64 notation.

Example:

String encoded = Base64.encode( myByteArray );
byte[] myByteArray = Base64.decode( encoded );

The options parameter, which appears in a few places, is used to pass several pieces of information to the encoder. In the "higher level" methods such as encodeBytes( bytes, options ) the options parameter can be used to indicate such things as first gzipping the bytes before encoding them, not inserting linefeeds, and encoding using the URL-safe and Ordered dialects.

Note, according to RFC3548, Section 2.1, implementations should not add line feeds unless explicitly told to do so. I've got Base64 set to this behavior now, although earlier versions broke lines by default.

The constants defined in Base64 can be OR-ed together to combine options, so you might make a call like this:

String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DO_BREAK_LINES );

to compress the data before encoding it and then making the output have newline characters.

Also...

String encoded = Base64.encodeBytes( crazyString.getBytes() );

Change Log:

v2.3.7 - Fixed subtle bug when base 64 input stream contained the value 01111111, which is an invalid base 64 character but should not throw an ArrayIndexOutOfBoundsException either. Led to discovery of mishandling (or potential for better handling) of other bad input characters. You should now get an IOException if you try decoding something that has bad characters in it.
v2.3.6 - Fixed bug when breaking lines and the final byte of the encoded string ended in the last column; the buffer was not properly shrunk and contained an extra (null) byte that made it into the string.
v2.3.5 - Fixed bug in encodeFromFile where estimated buffer size was wrong for files of size 31, 34, and 37 bytes.
v2.3.4 - Fixed bug when working with gzipped streams whereby flushing the Base64.OutputStream closed the Base64 encoding (by padding with equals signs) too soon. Also added an option to suppress the automatic decoding of gzipped streams. Also added experimental support for specifying a class loader when using the decodeToObject(String, int, ClassLoader) method.
v2.3.3 - Changed default char encoding to US-ASCII which reduces the internal Java footprint with its CharEncoders and so forth. Fixed some javadocs that were inconsistent. Removed imports and specified things like java.io.IOException explicitly inline.
v2.3.2 - Reduced memory footprint! Finally refined the "guessing" of how big the final encoded data will be so that the code doesn't have to create two output arrays: an oversized initial one and then a final, exact-sized one. Big win when using the encodeBytesToBytes(byte[]) family of methods (and not using the gzip options which uses a different mechanism with streams and stuff).
v2.3.1 - Added encodeBytesToBytes(byte[], int, int, int) and some similar helper methods to be more efficient with memory by not returning a String but just a byte array.
v2.3 - This is not a drop-in replacement! This is two years of comments and bug fixes queued up and finally executed. Thanks to everyone who sent me stuff, and I'm sorry I wasn't able to distribute your fixes to everyone else. Much bad coding was cleaned up including throwing exceptions where necessary instead of returning null values or something similar. Here are some changes that may affect you:
- Does not break lines, by default. This is to keep in compliance with RFC3548.
- Throws exceptions instead of returning null values. Because some operations (especially those that may permit the GZIP option) use IO streams, there is a possibility of an java.io.IOException being thrown. After some discussion and thought, I've changed the behavior of the methods to throw java.io.IOExceptions rather than return null if ever there's an error. I think this is more appropriate, though it will require some changes to your code. Sorry, it should have been done this way to begin with.
- Removed all references to System.out, System.err, and the like. Shame on me. All I can say is sorry they were ever there.
- Throws NullPointerExceptions and IllegalArgumentExceptions as needed such as when passed arrays are null or offsets are invalid.
- Cleaned up as much javadoc as I could to avoid any javadoc warnings. This was especially annoying before for people who were thorough in their own projects and then had gobs of javadoc warnings on this file.
v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when using very small files (~< 40 bytes).
v2.2 - Added some helper methods for encoding/decoding directly from one file to the next. Also added a main() method to support command line encoding/decoding from one file to the next. Also added these Base64 dialects:
1. The default is RFC3548 format.
2. Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates URL and file name friendly format as described in Section 4 of RFC3548. http://www.faqs.org/rfcs/rfc3548.html
3. Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates URL and file name friendly format that preserves lexical ordering as described in http://www.faqs.org/qa/rfcc-1940.html
Special thanks to Jim Kellerman at http://www.powerset.com/ for contributing the new Base64 dialects.
v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading and writing to and from files.
v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like EBCDIC).
v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.
v2.0 - I got rid of methods that used booleans to set options. Now everything is more consolidated and cleaner. The code now detects when data that's being decoded is gzip-compressed and will decompress it automatically. Generally things are cleaner. You'll probably have to change some method calls that you were making to support the new options format ( ints that you "OR" together).
v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using decode( String s, boolean gzipCompressed ). Added the ability to "suspend" encoding in the Output Stream so you can turn on and off the encoding if you need to embed base64 data in an otherwise "normal" stream (like an XML file).
v1.5 - Output stream passes 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.

Nested and Inner Type Summary

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

Field Summary

Modifier and Type	Field and Description
private static final byte[]	_ORDERED_ALPHABET I don't get the point of this technique, but someone requested it, and it is described here: http://www.faqs.org/qa/rfcc-1940.html.
private static final byte[]	_ORDERED_DECODABET Used in decoding the "ordered" dialect of Base64.
private static final byte[]	_STANDARD_ALPHABET The 64 valid Base64 values.
private static final byte[]	_STANDARD_DECODABET Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other meaning.
private static final byte[]	_URL_SAFE_ALPHABET Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html.
private static final byte[]	_URL_SAFE_DECODABET Used in decoding URL- and Filename-safe dialects of Base64.
public static final int	DECODE Specify decoding in first bit.
public static final int	DO_BREAK_LINES Do break lines when encoding.
public static final int	DONT_GUNZIP Specify that gzipped data should not be automatically gunzipped.
public static final int	ENCODE Specify encoding in first bit.
private static final byte	EQUALS_SIGN The equals sign (=) as a byte.
private static final byte	EQUALS_SIGN_ENC
public static final int	GZIP Specify that data should be gzip-compressed in second bit.
private static final int	MAX_LINE_LENGTH Maximum line length (76) of Base64 output.
private static final byte	NEW_LINE The new line character (\n) as a byte.
public static final int	NO_OPTIONS No options specified.
public static final int	ORDERED Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.
public static final int	URL_SAFE Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html.
private static final byte	WHITE_SPACE_ENC

Constructor Summary

Access	Constructor and Description
private	Base64() Defeats instantiation.

Method Summary

Modifier and Type	Method and Description
public static byte[]	Returns: decoded data decode(byte[] The Base64 encoded data source) Low-level access to decoding ASCII characters in the form of a byte array.
public static byte[]	Returns: decoded data decode(byte[] The Base64 encoded data source, int The offset of where to begin decoding off, int The length of characters to decode len, int Can specify options such as alphabet type to use options) Low-level access to decoding ASCII characters in the form of a byte array.
public static byte[]	Returns: the decoded data decode(String the string to decode s) Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
public static byte[]	Returns: the decoded data decode(String the string to decode s, int encode options such as URL_SAFE options) Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
private static int	Returns: the number of decoded bytes converted decode4to3(byte[] the array to convert source, int the index where conversion begins srcOffset, byte[] the array to hold the conversion destination, int the index where output will be put destOffset, int alphabet type is pulled from this (standard, url-safe, ordered) options) Decodes four bytes from array `source` and writes the resulting bytes (up to three of them) to `destination`.
public static void	decodeFileToFile(String Input file infile, String Output file outfile) Reads `infile` and decodes it to `outfile`.
public static byte[]	Returns: decoded byte array decodeFromFile(String Filename for reading encoded data filename) Convenience method for reading a base64-encoded file and decoding it.
public static void	decodeToFile(String Base64-encoded data as a string dataToDecode, String Filename for saving decoded data filename) Convenience method for decoding data to a file.
public static Object	Returns: The decoded and deserialized object decodeToObject(String The Base64 data to decode encodedObject) Attempts to decode Base64 data and deserialize a Java Object within.
public static Object	Returns: The decoded and deserialized object decodeToObject(String The Base64 data to decode encodedObject, int Various parameters related to decoding options, final ClassLoader Optional class loader to use in deserializing classes. loader) Attempts to decode Base64 data and deserialize a Java Object within.
public static void	encode(ByteBuffer input buffer raw, ByteBuffer output buffer encoded) Performs Base64 encoding on the `raw` ByteBuffer, writing it to the `encoded` ByteBuffer.
public static void	encode(ByteBuffer input buffer raw, CharBuffer output buffer encoded) Performs Base64 encoding on the `raw` ByteBuffer, writing it to the `encoded` CharBuffer.
private static byte[]	Returns: four byte array in Base64 notation. encode3to4(byte[] A reusable byte array to reduce array instantiation b4, byte[] the array to convert threeBytes, int the number of significant bytes in your array numSigBytes, int options) Encodes up to the first three bytes of array `threeBytes` and returns a four-byte array in Base64 notation.
private static byte[]	Returns: the `destination` array encode3to4(byte[] the array to convert source, int the index where conversion begins srcOffset, int the number of significant bytes in your array numSigBytes, byte[] the array to hold the conversion destination, int the index where output will be put destOffset, int options) Encodes up to three bytes of the array `source` and writes the resulting four Base64 bytes to `destination`.
public static String	Returns: The data in Base64-encoded form encodeBytes(byte[] The data to convert source) Encodes a byte array into Base64 notation.
public static String	Returns: The Base64-encoded data as a String encodeBytes(byte[] The data to convert source, int Specified options options) Encodes a byte array into Base64 notation.
public static String	Returns: The Base64-encoded data as a String encodeBytes(byte[] The data to convert source, int Offset in array where conversion should begin off, int Length of data to convert len) Encodes a byte array into Base64 notation.
public static String	Returns: The Base64-encoded data as a String encodeBytes(byte[] The data to convert source, int Offset in array where conversion should begin off, int Length of data to convert len, int Specified options options) Encodes a byte array into Base64 notation.
public static byte[]	Returns: The Base64-encoded data as a byte[] (of ASCII characters) encodeBytesToBytes(byte[] The data to convert source) Similar to `encodeBytes(byte[])` but returns a byte array instead of instantiating a String.
public static byte[]	Returns: The Base64-encoded data as a String encodeBytesToBytes(byte[] The data to convert source, int Offset in array where conversion should begin off, int Length of data to convert len, int Specified options options) Similar to `encodeBytes(byte[], int, int, int)` but returns a byte array instead of instantiating a String.
public static void	encodeFileToFile(String Input file infile, String Output file outfile) Reads `infile` and encodes it to `outfile`.
public static String	Returns: base64-encoded string encodeFromFile(String Filename for reading binary data filename) Convenience method for reading a binary file and base64-encoding it.
public static String	Returns: The Base64-encoded object encodeObject(Serializable The object to encode serializableObject) Serializes an object and returns the Base64-encoded version of that serialized object.
public static String	Returns: The Base64-encoded object encodeObject(Serializable The object to encode serializableObject, int Specified options options) Serializes an object and returns the Base64-encoded version of that serialized object.
public static void	encodeToFile(byte[] byte array of data to encode in base64 form dataToEncode, String Filename for saving encoded data filename) Convenience method for encoding data to a file.
private static byte[]	getAlphabet(int options) Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified.
private static byte[]	getDecodabet(int options) Returns one of the _SOMETHING_DECODABET byte arrays depending on the options specified.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

pack-priv Class Base64

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary