Base64

Page Summary

• The Base64 class provides methods to encode and decode binary data using the Base64 scheme as defined in RFC 2045 and RFC 3548.

• It offers encoding and decoding functionalities for byte arrays and strings, with options to customize the output using flags.

• Flags like NO_PADDING, NO_WRAP, and URL_SAFE control output formatting for different use cases.

• Developers can decode Base64-encoded data obtained from various sources, accommodating optional padding characters.

• The encodeToString methods offer convenient ways to get Base64-encoded data directly as a String.

public class Base64 extends Object

Utilities for encoding and decoding the Base64 representation of binary data. See RFCs 2045 and 3548.

Constant Summary

int	CRLF	Encoder flag bit to indicate lines should be terminated with a CRLF pair instead of just an LF.
int	DEFAULT	Default values for encoder/decoder flags.
int	NO_CLOSE	Flag to pass to Base64OutputStream to indicate that it should not close the output stream it is wrapping when it itself is closed.
int	NO_PADDING	Encoder flag bit to omit the padding '=' characters at the end of the output (if any).
int	NO_WRAP	Encoder flag bit to omit all line terminators (i.e., the output will be on one long line).
int	URL_SAFE	Encoder/decoder flag bit to indicate using the "URL and filename safe" variant of Base64 (see RFC 3548 section 4) where - and _ are used in place of + and /.

Public Method Summary

static byte[]	decode(String str, int flags) Decode the Base64-encoded data in input and return the data in a new byte array.
static byte[]	decode(byte[] input, int flags) Decode the Base64-encoded data in input and return the data in a new byte array.
static byte[]	decode(byte[] input, int offset, int len, int flags) Decode the Base64-encoded data in input and return the data in a new byte array.
static byte[]	encode(byte[] input, int flags) Base64-encode the given data and return a newly allocated byte[] with the result.
static byte[]	encode(byte[] input, int offset, int len, int flags) Base64-encode the given data and return a newly allocated byte[] with the result.
static String	encodeToString(byte[] input, int offset, int len, int flags) Base64-encode the given data and return a newly allocated String with the result.
static String	encodeToString(byte[] input, int flags) Base64-encode the given data and return a newly allocated String with the result.

Inherited Method Summary

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Constants

public static final int CRLF

Encoder flag bit to indicate lines should be terminated with a CRLF pair instead of just an LF. Has no effect if NO_WRAP is specified as well.

Constant Value: 4

public static final int DEFAULT

Default values for encoder/decoder flags.

Constant Value: 0

public static final int NO_CLOSE

Flag to pass to Base64OutputStream to indicate that it should not close the output stream it is wrapping when it itself is closed.

Constant Value: 16

public static final int NO_PADDING

Encoder flag bit to omit the padding '=' characters at the end of the output (if any).

Constant Value: 1

public static final int NO_WRAP

Encoder flag bit to omit all line terminators (i.e., the output will be on one long line).

Constant Value: 2

public static final int URL_SAFE

Encoder/decoder flag bit to indicate using the "URL and filename safe" variant of Base64 (see RFC 3548 section 4) where - and _ are used in place of + and /.

Constant Value: 8

Public Methods

public static byte[] decode (String str, int flags)

Decode the Base64-encoded data in input and return the data in a new byte array.

The padding '=' characters at the end are considered optional, but if any are present, there must be the correct number of them.

Parameters

str	the input String to decode, which is converted to bytes using the default charset
flags	controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.

Throws

IllegalArgumentException	if the input contains incorrect padding

public static byte[] decode (byte[] input, int flags)

Decode the Base64-encoded data in input and return the data in a new byte array.

The padding '=' characters at the end are considered optional, but if any are present, there must be the correct number of them.

Parameters

input	the input array to decode
flags	controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.

Throws

IllegalArgumentException	if the input contains incorrect padding

public static byte[] decode (byte[] input, int offset, int len, int flags)

Decode the Base64-encoded data in input and return the data in a new byte array.

The padding '=' characters at the end are considered optional, but if any are present, there must be the correct number of them.

Parameters

input	the data to decode
offset	the position within the input array at which to start
len	the number of bytes of input to decode
flags	controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.

Throws

IllegalArgumentException	if the input contains incorrect padding

public static byte[] encode (byte[] input, int flags)

Base64-encode the given data and return a newly allocated byte[] with the result.

Parameters

input	the data to encode
flags	controls certain features of the encoded output. Passing DEFAULT results in output that adheres to RFC 2045.

public static byte[] encode (byte[] input, int offset, int len, int flags)

Base64-encode the given data and return a newly allocated byte[] with the result.

Parameters

input	the data to encode
offset	the position within the input array at which to start
len	the number of bytes of input to encode
flags	controls certain features of the encoded output. Passing DEFAULT results in output that adheres to RFC 2045.

public static String encodeToString (byte[] input, int offset, int len, int flags)

Base64-encode the given data and return a newly allocated String with the result.

Parameters

input	the data to encode
offset	the position within the input array at which to start
len	the number of bytes of input to encode
flags	controls certain features of the encoded output. Passing DEFAULT results in output that adheres to RFC 2045.

public static String encodeToString (byte[] input, int flags)

Base64-encode the given data and return a newly allocated String with the result.

Parameters

input	the data to encode
flags	controls certain features of the encoded output. Passing DEFAULT results in output that adheres to RFC 2045.