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:

v2.3.8 - Fixed automatic gzip decoding, based on the content, as this may lead to unexpected behaviour. Request either gzipped or non gzipped decoding as excepted. Automatic encoding is especially problematic with generated input (see KEYCLOAK-18914 for a detailed case).
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(java.lang.String, int, java.lang.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 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.

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	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	GUNZIP Specify that data should be gunzipped.
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.
private static final String	PREFERRED_ENCODING Preferred encoding.
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 decode options such as URL_SAFE or GUNZIP 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	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 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.
private static final byte[]	getAlphabet(int options) Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified.
private static final 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

Field Detail

_ORDERED_ALPHABET	back to summary
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.

_ORDERED_DECODABET	back to summary
private static final byte[] _ORDERED_DECODABET Used in decoding the "ordered" dialect of Base64.

_STANDARD_ALPHABET	back to summary
private static final byte[] _STANDARD_ALPHABET The 64 valid Base64 values.

_STANDARD_DECODABET	back to summary
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.

_URL_SAFE_ALPHABET	back to summary
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. Notice that the last two bytes become "hyphen" and "underscore" instead of "plus" and "slash."

_URL_SAFE_DECODABET	back to summary
private static final byte[] _URL_SAFE_DECODABET Used in decoding URL- and Filename-safe dialects of Base64.

DECODE	back to summary
public static final int DECODE Specify decoding in first bit. Value is zero.

DO_BREAK_LINES	back to summary
public static final int DO_BREAK_LINES Do break lines when encoding. Value is 8.

ENCODE	back to summary
public static final int ENCODE Specify encoding in first bit. Value is one.

EQUALS_SIGN	back to summary
private static final byte EQUALS_SIGN The equals sign (=) as a byte.

EQUALS_SIGN_ENC	back to summary
private static final byte EQUALS_SIGN_ENC

GUNZIP	back to summary
public static final int GUNZIP Specify that data should be gunzipped.

GZIP	back to summary
public static final int GZIP Specify that data should be gzip-compressed in second bit. Value is two.

MAX_LINE_LENGTH	back to summary
private static final int MAX_LINE_LENGTH Maximum line length (76) of Base64 output.

NEW_LINE	back to summary
private static final byte NEW_LINE The new line character (\n) as a byte.

NO_OPTIONS	back to summary
public static final int NO_OPTIONS No options specified. Value is zero.

ORDERED	back to summary
public static final int ORDERED Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.

PREFERRED_ENCODING	back to summary
private static final String PREFERRED_ENCODING Preferred encoding.

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

WHITE_SPACE_ENC	back to summary
private static final byte WHITE_SPACE_ENC

Constructor Detail

Base64	back to summary
private Base64() Defeats instantiation.

Method Detail

decode	back to summary
public static byte[] decode(byte[] source) throws IOException Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's set. This is not generally a recommended method, although it is used internally as part of the decoding process. Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and aren't gzipping), consider this method. Parameters source:byte[] The Base64 encoded data Returns:byte[] decoded data Since 2.3.1

decode

back to summary

public static byte[] decode(byte[] source) throws IOException

Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's set. This is not generally a recommended method, although it is used internally as part of the decoding process. Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and aren't gzipping), consider this method.

Parameters

source:byte[]: The Base64 encoded data

Returns:byte[]

decoded data

Since

2.3.1

decode	back to summary
public static byte[] decode(byte[] source, int off, int len, int options) throws IOException Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's set. This is not generally a recommended method, although it is used internally as part of the decoding process. Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and aren't gzipping), consider this method. Parameters source:byte[] The Base64 encoded data off:int The offset of where to begin decoding len:int The length of characters to decode options:int Can specify options such as alphabet type to use Returns:byte[] decoded data Exceptions IOException: If bogus characters exist in source data Since 1.3

decode

back to summary

public static byte[] decode(byte[] source, int off, int len, int options) throws IOException

Parameters

source:byte[]: The Base64 encoded data
off:int: The offset of where to begin decoding
len:int: The length of characters to decode
options:int: Can specify options such as alphabet type to use

Returns:byte[]

decoded data

Exceptions

IOException:: If bogus characters exist in source data

Since

1.3

decode	back to summary
public static byte[] decode(String s) throws IOException Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it. Parameters s:String the string to decode Returns:byte[] the decoded data Exceptions IOException: If there is a problem Since 1.4

decode

back to summary

public static byte[] decode(String s) throws IOException

Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.

Parameters

s:String: the string to decode

Returns:byte[]

the decoded data

Exceptions

IOException:: If there is a problem

Since

1.4

decode back to summary

decode	back to summary
public static byte[] decode(String s, int options) throws IOException Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it. Parameters s:String the string to decode options:int decode options such as URL_SAFE or GUNZIP Returns:byte[] the decoded data Exceptions IOException: if there is an error (invalid character in source string or gunzip error) NullPointerException: if `s` is null Since 1.4

public static byte[] decode(String s, int options) throws IOException

Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.

Parameters

s:String: the string to decode
options:int: decode options such as URL_SAFE or GUNZIP

Returns:byte[]

the decoded data

Exceptions

IOException:: if there is an error (invalid character in source string or gunzip error)
NullPointerException:: if s is null

Since

1.4

decode4to3	back to summary
private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options) 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. Parameters source:byte[] the array to convert srcOffset:int the index where conversion begins destination:byte[] the array to hold the conversion destOffset:int the index where output will be put options:int alphabet type is pulled from this (standard, url-safe, ordered) Returns:int the number of decoded bytes converted Exceptions NullPointerException: if source or destination arrays are null IllegalArgumentException: if srcOffset or destOffset are invalid or there is not enough room in the array. Since 1.3

decode4to3

back to summary

private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options)

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.

Parameters

source:byte[]: the array to convert
srcOffset:int: the index where conversion begins
destination:byte[]: the array to hold the conversion
destOffset:int: the index where output will be put
options:int: alphabet type is pulled from this (standard, url-safe, ordered)

Returns:int

the number of decoded bytes converted

Exceptions

NullPointerException:: if source or destination arrays are null
IllegalArgumentException:: if srcOffset or destOffset are invalid or there is not enough room in the array.

Since

1.3

encode back to summary

encode	back to summary
public static void encode(ByteBuffer raw, ByteBuffer encoded) Performs Base64 encoding on the `raw` ByteBuffer, writing it to the `encoded` ByteBuffer. This is an experimental feature. Currently it does not pass along any options (such as `DO_BREAK_LINES` or `GZIP`). Parameters raw:ByteBuffer input buffer encoded:ByteBuffer output buffer Since 2.3

public static void encode(ByteBuffer raw, ByteBuffer encoded)

Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded ByteBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP).

Parameters

raw:ByteBuffer: input buffer
encoded:ByteBuffer: output buffer

Since

2.3

encode back to summary

encode	back to summary
public static void encode(ByteBuffer raw, CharBuffer encoded) Performs Base64 encoding on the `raw` ByteBuffer, writing it to the `encoded` CharBuffer. This is an experimental feature. Currently it does not pass along any options (such as `DO_BREAK_LINES` or `GZIP`. Parameters raw:ByteBuffer input buffer encoded:CharBuffer output buffer Since 2.3

public static void encode(ByteBuffer raw, CharBuffer encoded)

Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded CharBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP.

Parameters

raw:ByteBuffer: input buffer
encoded:CharBuffer: output buffer

Since

2.3

encode3to4	back to summary
private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options) 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`. Parameters b4:byte[] A reusable byte array to reduce array instantiation threeBytes:byte[] the array to convert numSigBytes:int the number of significant bytes in your array Returns:byte[] four byte array in Base64 notation. Since 1.5.1

encode3to4

back to summary

private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options)

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.

Parameters

b4:byte[]: A reusable byte array to reduce array instantiation
threeBytes:byte[]: the array to convert
numSigBytes:int: the number of significant bytes in your array

Returns:byte[]

four byte array in Base64 notation.

Since

1.5.1

encode3to4	back to summary
private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset, int options) 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 accommodate `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. Parameters source:byte[] the array to convert srcOffset:int the index where conversion begins numSigBytes:int the number of significant bytes in your array destination:byte[] the array to hold the conversion destOffset:int the index where output will be put Returns:byte[] the `destination` array Since 1.3

encode3to4

back to summary

private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset, int options)

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 accommodate 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.

Parameters

source:byte[]: the array to convert
srcOffset:int: the index where conversion begins
numSigBytes:int: the number of significant bytes in your array
destination:byte[]: the array to hold the conversion
destOffset:int: the index where output will be put

Returns:byte[]

the destination array

Since

1.3

encodeBytes	back to summary
public static String encodeBytes(byte[] source) Encodes a byte array into Base64 notation. Does not GZip-compress data. Parameters source:byte[] The data to convert Returns:String The data in Base64-encoded form Exceptions NullPointerException: if source array is null Since 1.4

encodeBytes

back to summary

public static String encodeBytes(byte[] source)

Encodes a byte array into Base64 notation. Does not GZip-compress data.

Parameters

source:byte[]: The data to convert

Returns:String

The data in Base64-encoded form

Exceptions

NullPointerException:: if source array is null

Since

1.4

encodeBytes back to summary

encodeBytes	back to summary
public static String encodeBytes(byte[] source, int options) throws IOException Encodes a byte array into Base64 notation. Example options: GZIP: gzip-compresses object before encoding it. DO_BREAK_LINES: break lines at 76 characters Note: Technically, without line break your encoding may become non-compliant (see rfc2045 and rfc4648). Example: `encodeBytes( myData, Base64.GZIP )` or Example: `encodeBytes( myData, Base64.GZIP \| Base64.DO_BREAK_LINES )` As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it. Parameters source:byte[] The data to convert options:int Specified options Returns:String The Base64-encoded data as a String Exceptions IOException: if there is an error NullPointerException: if source array is null Since 2.0 See Also `Base64#GZIP`, `Base64#DO_BREAK_LINES`

public static String encodeBytes(byte[] source, int options) throws IOException

Encodes a byte array into Base64 notation.

Example options:

  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: break lines at 76 characters
    Note: Technically, without line break your encoding may become non-compliant (see rfc2045 and rfc4648).

Example: encodeBytes( myData, Base64.GZIP ) or

Example: encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )

As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

Parameters

source:byte[]: The data to convert
options:int: Specified options

Returns:String

The Base64-encoded data as a String

Exceptions

IOException:: if there is an error
NullPointerException:: if source array is null

Since

2.0

See Also

Base64#GZIP, Base64#DO_BREAK_LINES

encodeBytes	back to summary
public static String encodeBytes(byte[] source, int off, int len) Encodes a byte array into Base64 notation. Does not GZip-compress data. As of v 2.3, if there is an error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it. Parameters source:byte[] The data to convert off:int Offset in array where conversion should begin len:int Length of data to convert Returns:String The Base64-encoded data as a String Exceptions NullPointerException: if source array is null IllegalArgumentException: if source array, offset, or length are invalid Since 1.4

encodeBytes

back to summary

public static String encodeBytes(byte[] source, int off, int len)

Encodes a byte array into Base64 notation. Does not GZip-compress data.

As of v 2.3, if there is an error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

Parameters

source:byte[]: The data to convert
off:int: Offset in array where conversion should begin
len:int: Length of data to convert

Returns:String

The Base64-encoded data as a String

Exceptions

NullPointerException:: if source array is null
IllegalArgumentException:: if source array, offset, or length are invalid

Since

1.4

encodeBytes back to summary

encodeBytes	back to summary
public static String encodeBytes(byte[] source, int off, int len, int options) throws IOException Encodes a byte array into Base64 notation. Example options: GZIP: gzip-compresses object before encoding it. DO_BREAK_LINES: 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.DO_BREAK_LINES )` As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it. Parameters source:byte[] The data to convert off:int Offset in array where conversion should begin len:int Length of data to convert options:int Specified options Returns:String The Base64-encoded data as a String Exceptions IOException: if there is an error NullPointerException: if source array is null IllegalArgumentException: if source array, offset, or length are invalid Since 2.0 See Also `Base64#GZIP`, `Base64#DO_BREAK_LINES`

public static String encodeBytes(byte[] source, int off, int len, int options) throws IOException

Encodes a byte array into Base64 notation.

Example options:

  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: 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.DO_BREAK_LINES )

Parameters

source:byte[]: The data to convert
off:int: Offset in array where conversion should begin
len:int: Length of data to convert
options:int: Specified options

Returns:String

The Base64-encoded data as a String

Exceptions

IOException:: if there is an error
NullPointerException:: if source array is null
IllegalArgumentException:: if source array, offset, or length are invalid

Since

2.0

See Also

Base64#GZIP, Base64#DO_BREAK_LINES

encodeBytesToBytes back to summary

encodeBytesToBytes	back to summary
public static byte[] encodeBytesToBytes(byte[] source) Similar to `encodeBytes(byte[])` but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode. Parameters source:byte[] The data to convert Returns:byte[] The Base64-encoded data as a byte[] (of ASCII characters) Exceptions NullPointerException: if source array is null Since 2.3.1

public static byte[] encodeBytesToBytes(byte[] source)

Similar to encodeBytes(byte[]) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode.

Parameters

source:byte[]: The data to convert

Returns:byte[]

The Base64-encoded data as a byte[] (of ASCII characters)

Exceptions

NullPointerException:: if source array is null

Since

2.3.1

encodeBytesToBytes back to summary

encodeBytesToBytes	back to summary
public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws IOException Similar to `encodeBytes(byte[], int, int, int)` but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode. Parameters source:byte[] The data to convert off:int Offset in array where conversion should begin len:int Length of data to convert options:int Specified options Returns:byte[] The Base64-encoded data as a String Exceptions IOException: if there is an error NullPointerException: if source array is null IllegalArgumentException: if source array, offset, or length are invalid Since 2.3.1 See Also `Base64#GZIP`, `Base64#DO_BREAK_LINES`

public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws IOException

Similar to encodeBytes(byte[], int, int, int) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode.

Parameters

source:byte[]: The data to convert
off:int: Offset in array where conversion should begin
len:int: Length of data to convert
options:int: Specified options

Returns:byte[]

The Base64-encoded data as a String

Exceptions

IOException:: if there is an error
NullPointerException:: if source array is null
IllegalArgumentException:: if source array, offset, or length are invalid

Since

2.3.1

See Also

Base64#GZIP, Base64#DO_BREAK_LINES

encodeObject	back to summary
public static String encodeObject(Serializable serializableObject) throws IOException Serializes an object and returns the Base64-encoded version of that serialized object. As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it. The object is not GZip-compressed before being encoded. Parameters serializableObject:Serializable The object to encode Returns:String The Base64-encoded object Exceptions IOException: if there is an error NullPointerException: if serializedObject is null Since 1.4

encodeObject

back to summary

public static String encodeObject(Serializable serializableObject) throws IOException

Serializes an object and returns the Base64-encoded version of that serialized object.

As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

The object is not GZip-compressed before being encoded.

Parameters

serializableObject:Serializable: The object to encode

Returns:String

The Base64-encoded object

Exceptions

IOException:: if there is an error
NullPointerException:: if serializedObject is null

Since

1.4

encodeObject back to summary

encodeObject	back to summary
public static String encodeObject(Serializable serializableObject, int options) throws IOException Serializes an object and returns the Base64-encoded version of that serialized object. As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException. This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it. The object is not GZip-compressed before being encoded. Example options: GZIP: gzip-compresses object before encoding it. DO_BREAK_LINES: break lines at 76 characters Example: `encodeObject( myObj, Base64.GZIP )` or Example: `encodeObject( myObj, Base64.GZIP \| Base64.DO_BREAK_LINES )` Parameters serializableObject:Serializable The object to encode options:int Specified options Returns:String The Base64-encoded object Exceptions IOException: if there is an error Since 2.0 See Also `Base64#GZIP`, `Base64#DO_BREAK_LINES`

public static String encodeObject(Serializable serializableObject, int options) throws IOException

Serializes an object and returns the Base64-encoded version of that serialized object.

The object is not GZip-compressed before being encoded.

Example options:

  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: break lines at 76 characters

Example: encodeObject( myObj, Base64.GZIP ) or

Example: encodeObject( myObj, Base64.GZIP | Base64.DO_BREAK_LINES )

Parameters

serializableObject:Serializable: The object to encode
options:int: Specified options

Returns:String

The Base64-encoded object

Exceptions

IOException:: if there is an error

Since

2.0

See Also

Base64#GZIP, Base64#DO_BREAK_LINES

getAlphabet	back to summary
private static final byte[] getAlphabet(int options) 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.

getDecodabet	back to summary
private static final byte[] getDecodabet(int options) 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.

org.keycloak.common.util back to summary

public Class Base64.InputStream

Class Inheritance

extends FilterInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.keycloak.common.util.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.

Since: 1.3
See Also: Base64

Field Summary

Modifier and Type	Field and Description
private boolean	breakLines
private byte[]	buffer
private int	bufferLength
private byte[]	decodabet
private boolean	encode
private int	lineLength
private int	numSigBytes
private int	options
private int	position

Inherited from java.io.FilterInputStream:: in

Constructor Summary

Access	Constructor and Description
public	InputStream(InputStream the `java.io.InputStream` from which to read data. in) Constructs a `Base64.InputStream` in DECODE mode.
public	InputStream(InputStream the `java.io.InputStream` from which to read data. in, int Specified options options) Constructs a `Base64.InputStream` in either ENCODE or DECODE mode.

Method Summary

Modifier and Type	Method and Description
public int	Returns: next byte read() Overrides java.io.FilterInputStream.read. Reads enough of the input stream to convert to/from Base64 and returns the next byte.
public int	Returns: bytes read into array or -1 if end of stream is encountered. read(byte[] array to hold values dest, int offset for array off, int max number of bytes to read into array len) Overrides java.io.FilterInputStream.read. Calls `read()` repeatedly until the end of stream is reached or `len` bytes are read.

Inherited from java.io.FilterInputStream:: available close mark markSupported read reset skip

Field Detail

breakLines	back to summary
private boolean breakLines

buffer	back to summary
private byte[] buffer

bufferLength	back to summary
private int bufferLength

decodabet	back to summary
private byte[] decodabet

encode	back to summary
private boolean encode

lineLength	back to summary
private int lineLength

numSigBytes	back to summary
private int numSigBytes

options	back to summary
private int options

position	back to summary
private int position

Constructor Detail

InputStream back to summary

public InputStream(InputStream in)

Constructs a Base64.InputStream in DECODE mode.

Parameters

in:InputStream: the java.io.InputStream from which to read data.

Since

1.3

InputStream back to summary

public InputStream(InputStream in, int options)

Constructs a Base64.InputStream in either ENCODE or DECODE mode.

Valid options:

  ENCODE or DECODE: Encode or Decode as data is read.
  DO_BREAK_LINES: break lines at 76 characters
    (only meaningful when encoding)

Example: new Base64.InputStream( in, Base64.DECODE )

Parameters

in:InputStream: the java.io.InputStream from which to read data.
options:int: Specified options

Since

2.0

Method Detail

read

back to summary

public int read() throws IOException

Overrides java.io.FilterInputStream.read.

Reads enough of the input stream to convert to/from Base64 and returns the next byte.

Returns:int

next byte

Annotations

@Override

Exceptions

IOException:

Doc from java.io.FilterInputStream.read.

if an I/O error occurs.

Since

1.3

read back to summary

public int read(byte[] dest, int off, int len) throws IOException

Overrides java.io.FilterInputStream.read.

Calls 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.

Parameters

dest:byte[]: array to hold values
off:int: offset for array
len:int: max number of bytes to read into array

Returns:int

bytes read into array or -1 if end of stream is encountered.

Annotations

@Override

Exceptions

IOException:

Doc from java.io.FilterInputStream.read.

if an I/O error occurs.

Since

1.3

org.keycloak.common.util back to summary

public Class Base64.OutputStream

Class Inheritance

extends FilterOutputStream

java.lang.Object
java.io.OutputStream
java.io.FilterOutputStream
org.keycloak.common.util.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.

Since: 1.3
See Also: Base64

Field Summary

Modifier and Type	Field and Description
private byte[]	b4
private boolean	breakLines
private byte[]	buffer
private int	bufferLength
private byte[]	decodabet
private boolean	encode
private int	lineLength
private int	options
private int	position
private boolean	suspendEncoding

Inherited from java.io.FilterOutputStream:: out

Constructor Summary

Access	Constructor and Description
public	OutputStream(OutputStream the `java.io.OutputStream` to which data will be written. out) Constructs a `Base64.OutputStream` in ENCODE mode.
public	OutputStream(OutputStream the `java.io.OutputStream` to which data will be written. out, int Specified options. options) Constructs a `Base64.OutputStream` in either ENCODE or DECODE mode.

Method Summary

Modifier and Type	Method and Description
public void	close() Overrides java.io.FilterOutputStream.close. Implements java.io.Closeable.close. Flushes and closes (I think, in the superclass) the stream.
public void	flushBase64() Method added by PHIL.
public void	resumeEncoding() Resumes encoding of the stream.
public void	suspendEncoding() Suspends encoding of the stream.
public void	write(int the byte to write theByte) Overrides java.io.FilterOutputStream.write. Writes the byte to the output stream after converting to/from Base64 notation.
public void	write(byte[] array from which to read bytes theBytes, int offset for array off, int max number of bytes to read into array len) Overrides java.io.FilterOutputStream.write. Calls `write(int)` repeatedly until `len` bytes are written.

Inherited from java.io.FilterOutputStream:: flush write

Field Detail

b4	back to summary
private byte[] b4

breakLines	back to summary
private boolean breakLines

buffer	back to summary
private byte[] buffer

bufferLength	back to summary
private int bufferLength

decodabet	back to summary
private byte[] decodabet

encode	back to summary
private boolean encode

lineLength	back to summary
private int lineLength

options	back to summary
private int options

position	back to summary
private int position

suspendEncoding	back to summary
private boolean suspendEncoding

Constructor Detail

OutputStream back to summary

public OutputStream(OutputStream out)

Constructs a Base64.OutputStream in ENCODE mode.

Parameters

out:OutputStream: the java.io.OutputStream to which data will be written.

Since

1.3

OutputStream back to summary

public OutputStream(OutputStream out, int options)

Constructs a Base64.OutputStream in either ENCODE or DECODE mode.

Valid options:

  ENCODE or DECODE: Encode or Decode as data is read.
  DO_BREAK_LINES: don't break lines at 76 characters
    (only meaningful when encoding)

Example: new Base64.OutputStream( out, Base64.ENCODE )

Parameters

out:OutputStream: the java.io.OutputStream to which data will be written.
options:int: Specified options.

Since

1.3

Method Detail

back to summary

public void close() throws IOException

Overrides java.io.FilterOutputStream.close.

Implements java.io.Closeable.close.

Flushes and closes (I think, in the superclass) the stream.

Annotations

@Override

Exceptions

IOException:

Doc from java.io.FilterOutputStream.close.

if an I/O error occurs.

Since

1.3

flushBase64

back to summary

public void flushBase64() throws IOException

Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer without closing the stream.

Exceptions

IOException:: if there's an error.

resumeEncoding

back to summary

public void resumeEncoding()

Resumes encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.

Since: 1.5.1

suspendEncoding

back to summary

public void suspendEncoding() throws IOException

Suspends encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.

Exceptions

IOException:: if there's an error flushing

Since

1.5.1

write

back to summary

public void write(int theByte) throws IOException

Overrides java.io.FilterOutputStream.write.

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.

Parameters