public class Base64 extends Object
Encodes and decodes to and from Base64 notation.
Homepage: http://iharder.net/base64.
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.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() );
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.
| Modifier and Type | Field | Description |
|---|---|---|
static int |
DO_BREAK_LINES |
Do break lines when encoding.
|
static int |
NO_OPTIONS |
No options specified.
|
static int |
ORDERED |
Encode using the special "ordered" dialect of Base64 described here:
http://www.faqs.org/qa/rfcc-1940.html.
|
static 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.
|
| Modifier and Type | Method | Description |
|---|---|---|
static byte[] |
decode(byte[] source) |
Low-level access to decoding ASCII characters in
the form of a byte array.
|
static byte[] |
decode(byte[] source,
int off,
int len,
int options) |
Low-level access to decoding ASCII characters in
the form of a byte array.
|
static byte[] |
decode(String s) |
Decodes data from Base64 notation, automatically
detecting gzip-compressed data and decompressing it.
|
static byte[] |
decode(String s,
int options) |
Decodes data from Base64 notation, automatically
detecting gzip-compressed data and decompressing it.
|
static String |
encodeBytes(byte[] source) |
Encodes a byte array into Base64 notation.
|
static String |
encodeBytes(byte[] source,
int off,
int len,
int options) |
Encodes a byte array into Base64 notation.
|
static byte[] |
encodeBytesToBytes(byte[] source,
int off,
int len,
int options) |
Similar to
encodeBytes(byte[], int, int, int) but returns
a byte array instead of instantiating a String. |
public static final int NO_OPTIONS
public static final int DO_BREAK_LINES
public static final int URL_SAFE
public static final int ORDERED
public static String encodeBytes(byte[] source)
source - The data to convertNullPointerException - if source array is nullpublic static String encodeBytes(byte[] source, int off, int len, int options) throws IOException
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 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.
source - The data to convertoff - Offset in array where conversion should beginlen - Length of data to convertoptions - Specified optionsIOException - if there is an errorNullPointerException - if source array is nullIllegalArgumentException - if source array, offset, or length are invalidDO_BREAK_LINESpublic static byte[] encodeBytesToBytes(byte[] source,
int off,
int len,
int options)
throws IOException
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.source - The data to convertoff - Offset in array where conversion should beginlen - Length of data to convertoptions - Specified optionsIOException - if there is an errorNullPointerException - if source array is nullIllegalArgumentException - if source array, offset, or length are invalidDO_BREAK_LINESpublic static byte[] decode(byte[] source)
throws IOException
source - The Base64 encoded dataIOException - if there is an errorpublic static byte[] decode(byte[] source,
int off,
int len,
int options)
throws IOException
source - The Base64 encoded dataoff - The offset of where to begin decodinglen - The length of characters to decodeoptions - Can specify options such as alphabet type to useIOException - If bogus characters exist in source datapublic static byte[] decode(String s) throws IOException
s - the string to decodeIOException - If there is a problempublic static byte[] decode(String s, int options) throws IOException
s - the string to decodeoptions - encode options such as URL_SAFEIOException - if there is an errorNullPointerException - if s is nullCopyright © 2026. All rights reserved.