com.fasterxml.jackson.core

Class Base64Variant

java.lang.Object

com.fasterxml.jackson.core.Base64Variant

All Implemented Interfaces:

Serializable

public final class Base64Variant
extends Object
implements Serializable

Abstract base class used to define specific details of which variant of Base64 encoding/decoding is to be used. Although there is somewhat standard basic version (so-called "MIME Base64"), other variants exists, see Base64 Wikipedia entry for details.

Author:

Tatu Saloranta

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	_maxLineLength Maximum number of encoded base64 characters to output during encoding before adding a linefeed, if line length is to be limited (Integer.MAX_VALUE if not limited).
protected String	_name Symbolic name of variant; used for diagnostics/debugging.
protected char	_paddingChar Characted used for padding, if any (PADDING_CHAR_NONE if not).
protected boolean	_usesPadding Whether this variant uses padding or not.
static int	BASE64_VALUE_INVALID Marker used to denote ascii characters that do not correspond to a 6-bit value (in this variant), and is not used as a padding character.
static int	BASE64_VALUE_PADDING Marker used to denote ascii character (in decoding table) that is the padding character using this variant (if any).

Constructor Summary

Constructors

Constructor and Description
Base64Variant(Base64Variant base, String name, boolean usesPadding, char paddingChar, int maxLineLength) "Copy constructor" that can be used when the base alphabet is identical to one used by another variant, but other details (padding, maximum line length) differ
Base64Variant(Base64Variant base, String name, int maxLineLength) "Copy constructor" that can be used when the base alphabet is identical to one used by another variant except for the maximum line length (and obviously, name).
Base64Variant(String name, String base64Alphabet, boolean usesPadding, char paddingChar, int maxLineLength)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	_reportBase64EOF()
protected void	_reportInvalidBase64(char ch, int bindex, String msg)
byte[]	decode(String input) Convenience method for decoding contents of a Base64-encoded String, using this variant's settings.
void	decode(String str, ByteArrayBuilder builder) Convenience method for decoding contents of a Base64-encoded String, using this variant's settings and appending decoded binary data using provided ByteArrayBuilder.
int	decodeBase64Byte(byte b)
int	decodeBase64Char(char c)
int	decodeBase64Char(int ch)
String	encode(byte[] input) Convenience method for converting given byte array as base64 encoded String using this variant's settings.
String	encode(byte[] input, boolean addQuotes) Convenience method for converting given byte array as base64 encoded String using this variant's settings, optionally enclosed in double-quotes.
byte	encodeBase64BitsAsByte(int value)
char	encodeBase64BitsAsChar(int value)
int	encodeBase64Chunk(int b24, byte[] buffer, int ptr) Method that encodes given right-aligned (LSB) 24-bit value into 4 base64 bytes (ascii), stored in given result buffer.
int	encodeBase64Chunk(int b24, char[] buffer, int ptr) Method that encodes given right-aligned (LSB) 24-bit value into 4 base64 characters, stored in given result buffer.
void	encodeBase64Chunk(StringBuilder sb, int b24)
int	encodeBase64Partial(int bits, int outputBytes, byte[] buffer, int outPtr) Method that outputs partial chunk (which only encodes one or two bytes of data).
int	encodeBase64Partial(int bits, int outputBytes, char[] buffer, int outPtr) Method that outputs partial chunk (which only encodes one or two bytes of data).
void	encodeBase64Partial(StringBuilder sb, int bits, int outputBytes)
boolean	equals(Object o)
int	getMaxLineLength()
String	getName()
byte	getPaddingByte()
char	getPaddingChar()
int	hashCode()
protected Object	readResolve() Method used to "demote" deserialized instances back to canonical ones
String	toString()
boolean	usesPadding()
boolean	usesPaddingChar(char c)
boolean	usesPaddingChar(int ch)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

BASE64_VALUE_INVALID

public static final int BASE64_VALUE_INVALID

Marker used to denote ascii characters that do not correspond to a 6-bit value (in this variant), and is not used as a padding character.

See Also:

Constant Field Values

BASE64_VALUE_PADDING

public static final int BASE64_VALUE_PADDING

Marker used to denote ascii character (in decoding table) that is the padding character using this variant (if any).

See Also:

Constant Field Values

_name

protected final String _name

Symbolic name of variant; used for diagnostics/debugging.

Note that this is the only non-transient field; used when reading back from serialized state

_usesPadding

protected final transient boolean _usesPadding

Whether this variant uses padding or not.

_paddingChar

protected final transient char _paddingChar

Characted used for padding, if any (PADDING_CHAR_NONE if not).

_maxLineLength

protected final transient int _maxLineLength

Maximum number of encoded base64 characters to output during encoding before adding a linefeed, if line length is to be limited (Integer.MAX_VALUE if not limited).

Note: for some output modes (when writing attributes) linefeeds may need to be avoided, and this value ignored.

Constructor Detail

Base64Variant

public Base64Variant(String name,
             String base64Alphabet,
             boolean usesPadding,
             char paddingChar,
             int maxLineLength)

Base64Variant

public Base64Variant(Base64Variant base,
             String name,
             int maxLineLength)

"Copy constructor" that can be used when the base alphabet is identical to one used by another variant except for the maximum line length (and obviously, name).

Base64Variant

public Base64Variant(Base64Variant base,
             String name,
             boolean usesPadding,
             char paddingChar,
             int maxLineLength)

"Copy constructor" that can be used when the base alphabet is identical to one used by another variant, but other details (padding, maximum line length) differ

Method Detail

readResolve

protected Object readResolve()

Method used to "demote" deserialized instances back to canonical ones

getName

public String getName()

usesPadding

public boolean usesPadding()

usesPaddingChar

public boolean usesPaddingChar(char c)

usesPaddingChar

public boolean usesPaddingChar(int ch)

getPaddingChar

public char getPaddingChar()

getPaddingByte

public byte getPaddingByte()

getMaxLineLength

public int getMaxLineLength()

decodeBase64Char

public int decodeBase64Char(char c)

Returns:

6-bit decoded value, if valid character;

decodeBase64Char

public int decodeBase64Char(int ch)

decodeBase64Byte

public int decodeBase64Byte(byte b)

encodeBase64BitsAsChar

public char encodeBase64BitsAsChar(int value)

encodeBase64Chunk

public int encodeBase64Chunk(int b24,
                    char[] buffer,
                    int ptr)

Method that encodes given right-aligned (LSB) 24-bit value into 4 base64 characters, stored in given result buffer.

encodeBase64Chunk

public void encodeBase64Chunk(StringBuilder sb,
                     int b24)

encodeBase64Partial

public int encodeBase64Partial(int bits,
                      int outputBytes,
                      char[] buffer,
                      int outPtr)

Method that outputs partial chunk (which only encodes one or two bytes of data). Data given is still aligned same as if it as full data; that is, missing data is at the "right end" (LSB) of int.

Parameters:

outputBytes - Number of encoded bytes included (either 1 or 2)

encodeBase64Partial

public void encodeBase64Partial(StringBuilder sb,
                       int bits,
                       int outputBytes)

encodeBase64BitsAsByte

public byte encodeBase64BitsAsByte(int value)

encodeBase64Chunk

public int encodeBase64Chunk(int b24,
                    byte[] buffer,
                    int ptr)

Method that encodes given right-aligned (LSB) 24-bit value into 4 base64 bytes (ascii), stored in given result buffer.

encodeBase64Partial

public int encodeBase64Partial(int bits,
                      int outputBytes,
                      byte[] buffer,
                      int outPtr)

Method that outputs partial chunk (which only encodes one or two bytes of data). Data given is still aligned same as if it as full data; that is, missing data is at the "right end" (LSB) of int.

Parameters:

outputBytes - Number of encoded bytes included (either 1 or 2)

encode

public String encode(byte[] input)

Convenience method for converting given byte array as base64 encoded String using this variant's settings. Resulting value is "raw", that is, not enclosed in double-quotes.

Parameters:

input - Byte array to encode

encode

public String encode(byte[] input,
            boolean addQuotes)

Convenience method for converting given byte array as base64 encoded String using this variant's settings, optionally enclosed in double-quotes.

Parameters:

input - Byte array to encode

addQuotes - Whether to surround resulting value in double quotes or not

decode

public byte[] decode(String input)
              throws IllegalArgumentException

Convenience method for decoding contents of a Base64-encoded String, using this variant's settings.

Parameters:

input -

Throws:

IllegalArgumentException - if input is not valid base64 encoded data

Since:

2.2.3

decode

public void decode(String str,
          ByteArrayBuilder builder)
            throws IllegalArgumentException

Convenience method for decoding contents of a Base64-encoded String, using this variant's settings and appending decoded binary data using provided ByteArrayBuilder.

NOTE: builder will NOT be reset before decoding (nor cleared afterwards); assumption is that caller will ensure it is given in proper state, and used as appropriate afterwards.

Throws:

IllegalArgumentException - if input is not valid base64 encoded data

Since:

2.2.3

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

_reportInvalidBase64

protected void _reportInvalidBase64(char ch,
                        int bindex,
                        String msg)
                             throws IllegalArgumentException

Parameters:

bindex - Relative index within base64 character unit; between 0 and 3 (as unit has exactly 4 characters)

Throws:

IllegalArgumentException

_reportBase64EOF

protected void _reportBase64EOF()
                         throws IllegalArgumentException

Throws:

IllegalArgumentException