Base64 (Android Utilities 2.7.0 API)

java.lang.Object
- android.util.Base64

```
public class Base64
extends Object
```
Utilities for encoding and decoding the Base64 representation of binary data. See RFCs 2045 and 3548.
Original Author: iharder Reference: http://iharder.sourceforge.net/current/java/base64/
NOTE: Note that the class is updated to to match the android.util.Base64 interface. Since that interface does not follow the Base64 standard this class also does not entirely follow the standard, notably:
- Standard base64 will wrap at 76 characters per default, as per RFC 2045, not only when requested as per RFC 3548.
- Even URL_SAFE encoding will both pad and wrap lines per default, which frankly makes it neither safe for URLs nor filenames.
- Line wrapping will only be applies as a splitter, it will never apply to the end of the encoded string. This is a divergence from the early implementation of the android.util.Base64 class at least.

Field Summary

Fields
Modifier and Type	Field and Description
`protected static byte`	`CR` The new carriage return (\r) as a byte.
`static int`	`CRLF` Encoder flag bit to indicate lines should be terminated with a CRLF pair instead of just an LF.
`static int`	`DEFAULT` Default values for encoder/decoder flags.
`protected static byte`	`EQUALS_SIGN` The equals sign (=) as a byte.
`protected static byte`	`LF` The new line character (\n) as a byte.
`protected static int`	`MAX_LINE_LENGTH` Maximum line length (76) of Base64 output.
`static 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.
`static int`	`NO_PADDING` Encoder flag bit to omit the padding '=' characters at the end of the output (if any).
`static int`	`NO_WRAP` Do not break lines when encoding.
`static 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 /.
`protected static byte`	`WHITE_SPACE_ENC`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static byte[]`	`decode(byte[] source, int options)` Decode the Base64-encoded data in input and return the data in a new byte array.
`static byte[]`	`decode(byte[] source, int offset, int len, int options)` Decode the Base64-encoded data in input and return the data in a new byte array.
`static byte[]`	`decode(String s, int options)` Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
`protected static int`	`decode4to3(byte[] src, int len, byte[] dest, int offset, byte[] decodabet)` Decodes four bytes from array `source` and writes the resulting bytes (up to three of them) to `destination`.
`static byte[]`	`encode(byte[] source, int options)` Similar to `encodeToString(byte[], int, int, int)` but returns a byte array instead of instantiating a String.
`static byte[]`	`encode(byte[] source, int off, int len, int options)` Similar to `encodeToString(byte[], int, int, int)` but returns a byte array instead of instantiating a String.
`protected static int`	`encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset, boolean noPadding, byte[] alphabet)` Encodes up to three bytes of the array `source` and writes the resulting four Base64 bytes to `destination`.
`static String`	`encodeToString(byte[] source, int options)` Encodes a byte array into Base64 notation.
`static String`	`encodeToString(byte[] source, int off, int len, int options)` Encodes a byte array into Base64 notation.
`protected static byte[]`	`getAlphabet(int options)` Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified.
`protected static byte[]`	`getDecodabet(int options)` Returns one of the _SOMETHING_DECODABET byte arrays depending on the options specified.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT
```
public static final int DEFAULT
```
    Default values for encoder/decoder flags.
    
    See Also:
    
    Constant Field Values
  - NO_PADDING
```
public static final int NO_PADDING
```
    Encoder flag bit to omit the padding '=' characters at the end of the output (if any).
    
    See Also:
    
    Constant Field Values
  - NO_WRAP
```
public static final int NO_WRAP
```
    Do not break lines when encoding. Value is 2.
    
    See Also:
    
    Constant Field Values
  - CRLF
```
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.
    
    See Also:
    
    Constant Field Values
  - URL_SAFE
```
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 /. URL_SAFE implies NO_WRAP and NO_PADDING.
    
    See Also:
    
    Constant Field Values
  - NO_CLOSE
```
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.
    
    See Also:
    
    Constant Field Values
  - MAX_LINE_LENGTH
```
protected static final int MAX_LINE_LENGTH
```
    Maximum line length (76) of Base64 output.
    
    See Also:
    
    Constant Field Values
  - EQUALS_SIGN
```
protected static final byte EQUALS_SIGN
```
    The equals sign (=) as a byte.
    
    See Also:
    
    Constant Field Values
  - CR
```
protected static final byte CR
```
    The new carriage return (\r) as a byte.
    
    See Also:
    
    Constant Field Values
  - LF
```
protected static final byte LF
```
    The new line character (\n) as a byte.
    
    See Also:
    
    Constant Field Values
  - WHITE_SPACE_ENC
```
protected static final byte WHITE_SPACE_ENC
```
    See Also:
    
    Constant Field Values
- Method Detail
  - getAlphabet
```
protected static 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.
    
    Parameters:
    
    options - Option used to determine alphabet.
    
    Returns:
    
    The alphabet pos to byte value array.
  - getDecodabet
```
protected static 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.
    
    Parameters:
    
    options - Option used to determine decodabet.
    
    Returns:
    
    The decodabet pos to byte value array.
  - encode3to4
```
protected static int encode3to4(byte[] source,
                                int srcOffset,
                                int numSigBytes,
                                byte[] destination,
                                int destOffset,
                                boolean noPadding,
                                byte[] alphabet)
```
    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.
    
    Parameters:
    
    source - the array to convert
    
    srcOffset - the index where conversion begins
    
    numSigBytes - the number of significant bytes in your array
    
    destination - the array to hold the conversion
    
    destOffset - the index where output will be put
    
    noPadding - True if no padding should be added.
    
    alphabet - The alphabet to use.
    
    Returns:
    
    the destination array
    
    Since:
    
    1.3
  - encodeToString
```
public static String encodeToString(byte[] source,
                                    int options)
```
    Encodes a byte array into Base64 notation.
    
    Parameters:
    
    source - The data to convert
    
    options - Specified options
    
    Returns:
    
    The Base64-encoded data as a String
    
    Throws:
    
    NullPointerException - if source array is null
    
    Since:
    
    2.0
    
    See Also:
    
    NO_WRAP
  - encodeToString
```
public static String encodeToString(byte[] source,
                                    int off,
                                    int len,
                                    int options)
```
    Encodes a byte array into Base64 notation.
    
    Parameters:
    
    source - The data to convert
    
    off - Offset in array where conversion should begin
    
    len - Length of data to convert
    
    options - Specified options
    
    Returns:
    
    The Base64-encoded data as a String
    
    Throws:
    
    NullPointerException - if source array is null
    
    IllegalArgumentException - if source array, offset, or length are invalid
    
    Since:
    
    2.0
    
    See Also:
    
    NO_WRAP
  - encode
```
public static byte[] encode(byte[] source,
                            int off,
                            int len,
                            int options)
```
    Similar to encodeToString(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 encodeToString.
    
    Parameters:
    
    source - The data to convert
    
    off - Offset in array where conversion should begin
    
    len - Length of data to convert
    
    options - Specified options
    
    Returns:
    
    The Base64-encoded data as a String
    
    Throws:
    
    NullPointerException - if source array is null
    
    IllegalArgumentException - if source array, offset, or length are invalid
    
    Since:
    
    2.3.1
    
    See Also:
    
    NO_WRAP, URL_SAFE, CRLF
  - encode
```
public static byte[] encode(byte[] source,
                            int options)
```
    Similar to encodeToString(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 encodeToString.
    
    Parameters:
    
    source - The data to convert
    
    options - Specified options
    
    Returns:
    
    The Base64-encoded data as a String
    
    Throws:
    
    NullPointerException - if source array is null
    
    IllegalArgumentException - if source array, offset, or length are invalid
    
    Since:
    
    2.3.1
    
    See Also:
    
    NO_WRAP
  - decode4to3
```
protected static int decode4to3(byte[] src,
                                int len,
                                byte[] dest,
                                int offset,
                                byte[] decodabet)
```
    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:
    
    src - the array to convert
    
    len - The number of bytes to read within src.
    
    dest - the array to hold the conversion
    
    offset - the index where output will be put
    
    decodabet - alphabet type is pulled from this (standard, url-safe, ordered)
    
    Returns:
    
    the number of decoded bytes converted
    
    Throws:
    
    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
  - decode
```
public static byte[] decode(byte[] source,
                            int options)
```
    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:
    
    source - The data to decode
    
    options - controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.
    
    Returns:
    
    decoded data
  - decode
```
public static byte[] decode(byte[] source,
                            int offset,
                            int len,
                            int options)
```
    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:
    
    source - The data to decode
    
    offset - The offset within the input array at which to start
    
    len - The number of byte sof input to decode.
    
    options - controls certain features of the decoded output. Pass DEFAULT to decode standard Base64.
    
    Returns:
    
    decoded data
  - decode
```
public static byte[] decode(String s,
                            int options)
```
    Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
    
    Parameters:
    
    s - the string to decode
    
    options - encodeToString options such as URL_SAFE
    
    Returns:
    
    the decoded data
    
    Throws:
    
    NullPointerException - if s is null

Class Base64

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT

NO_PADDING

NO_WRAP

CRLF

URL_SAFE

NO_CLOSE

MAX_LINE_LENGTH

EQUALS_SIGN

CR

LF

WHITE_SPACE_ENC

Method Detail

getAlphabet

getDecodabet

encode3to4

encodeToString

encodeToString

encode

encode

decode4to3

decode

decode

decode