BaseNCodec (Apache Tomcat 7.0.109 API Documentation)

java.lang.Object
- org.apache.tomcat.util.codec.binary.BaseNCodec

All Implemented Interfaces:

BinaryDecoder, BinaryEncoder, Decoder, Encoder

Direct Known Subclasses:

Base64
```
public abstract class BaseNCodec
extends Object
implements BinaryEncoder, BinaryDecoder
```
Abstract superclass for Base-N encoders and decoders.
This class is thread-safe.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`lineLength` Chunksize for encoding.
`protected static int`	`MASK_8BITS` Mask used to extract 8 bits, used in decoding bytes
`static int`	`MIME_CHUNK_SIZE` MIME chunk size per RFC 2045 section 6.8.
`protected byte`	`pad`
`protected static byte`	`PAD_DEFAULT` Byte used to pad output.
`static int`	`PEM_CHUNK_SIZE` PEM chunk size per RFC 1421 section 4.3.2.4.
`protected static StringManager`	`sm`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength)` Note `lineLength` is rounded down to the nearest multiple of the encoded block size.
`protected`	`BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad)` Note `lineLength` is rounded down to the nearest multiple of the encoded block size.

Method Summary

Methods
Modifier and Type	Method and Description
`protected boolean`	`containsAlphabetOrPad(byte[] arrayOctet)` Tests a given byte array to see if it contains any characters within the alphabet or PAD.
`byte[]`	`decode(byte[] pArray)` Decodes a byte[] containing characters in the Base-N alphabet.
`byte[]`	`decode(byte[] pArray, int off, int len)`
`Object`	`decode(Object obj)` Deprecated. This unused method will be removed in Tomcat 9
`byte[]`	`decode(String pArray)` Decodes a String containing characters in the Base-N alphabet.
`byte[]`	`encode(byte[] pArray)` Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
`byte[]`	`encode(byte[] pArray, int offset, int length)` Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
`Object`	`encode(Object obj)` Deprecated. This unused method will be removed in Tomcat 9
`String`	`encodeAsString(byte[] pArray)` Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet.
`String`	`encodeToString(byte[] pArray)` Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet.
`protected byte[]`	`ensureBufferSize(int size, org.apache.tomcat.util.codec.binary.BaseNCodec.Context context)` Ensure that the buffer has room for `size` bytes
`static byte[]`	`getChunkSeparator()` Gets a copy of the chunk separator per RFC 2045 section 2.1.
`protected int`	`getDefaultBufferSize()` Get the default buffer size.
`long`	`getEncodedLength(byte[] pArray)` Calculates the amount of space needed to encode the supplied array.
`protected abstract boolean`	`isInAlphabet(byte value)` Returns whether or not the `octet` is in the current alphabet.
`boolean`	`isInAlphabet(byte[] arrayOctet, boolean allowWSPad)` Tests a given byte array to see if it contains only valid characters within the alphabet.
`boolean`	`isInAlphabet(String basen)` Tests a given String to see if it contains only valid characters within the alphabet.
`protected static boolean`	`isWhiteSpace(byte byteToCheck)` Checks if a byte value is whitespace or not.

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

- Field Detail
  - sm
```
protected static final StringManager sm
```
  - MIME_CHUNK_SIZE
```
public static final int MIME_CHUNK_SIZE
```
    MIME chunk size per RFC 2045 section 6.8.
    The 76 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.
    
    See Also:
    RFC 2045 section 6.8, Constant Field Values
  - PEM_CHUNK_SIZE
```
public static final int PEM_CHUNK_SIZE
```
    PEM chunk size per RFC 1421 section 4.3.2.4.
    The 64 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.
    
    See Also:
    RFC 1421 section 4.3.2.4, Constant Field Values
  - MASK_8BITS
```
protected static final int MASK_8BITS
```
    Mask used to extract 8 bits, used in decoding bytes
    
    See Also:
    Constant Field Values
  - PAD_DEFAULT
```
protected static final byte PAD_DEFAULT
```
    Byte used to pad output.
    
    See Also:
    Constant Field Values
  - pad
```
protected final byte pad
```
  - lineLength
```
protected final int lineLength
```
    Chunksize for encoding. Not used when decoding. A value of zero or less implies no chunking of the encoded data. Rounded down to nearest multiple of encodedBlockSize.
- Constructor Detail
  - BaseNCodec
```
protected BaseNCodec(int unencodedBlockSize,
          int encodedBlockSize,
          int lineLength,
          int chunkSeparatorLength)
```
    Note lineLength is rounded down to the nearest multiple of the encoded block size. If chunkSeparatorLength is zero, then chunking is disabled.
    
    Parameters:
    unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)
    encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)
    lineLength - if > 0, use chunking with a length lineLength
    chunkSeparatorLength - the chunk separator length, if relevant
  - BaseNCodec
```
protected BaseNCodec(int unencodedBlockSize,
          int encodedBlockSize,
          int lineLength,
          int chunkSeparatorLength,
          byte pad)
```
    Note lineLength is rounded down to the nearest multiple of the encoded block size. If chunkSeparatorLength is zero, then chunking is disabled.
    
    Parameters:
    unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)
    encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)
    lineLength - if > 0, use chunking with a length lineLength
    chunkSeparatorLength - the chunk separator length, if relevant
    pad - byte used as padding byte.
- Method Detail
  - getChunkSeparator
```
public static byte[] getChunkSeparator()
```
    Gets a copy of the chunk separator per RFC 2045 section 2.1.
    
    Returns:
    the chunk separator
    Since:
    
    1.15
    
    See Also:
    RFC 2045 section 2.1
  - isWhiteSpace
```
protected static boolean isWhiteSpace(byte byteToCheck)
```
    Checks if a byte value is whitespace or not. Whitespace is taken to mean: space, tab, CR, LF
    
    Parameters:
    byteToCheck - the byte to check
    
    Returns:
    true if byte is whitespace, false otherwise
  - containsAlphabetOrPad
```
protected boolean containsAlphabetOrPad(byte[] arrayOctet)
```
    Tests a given byte array to see if it contains any characters within the alphabet or PAD. Intended for use in checking line-ending arrays
    
    Parameters:
    arrayOctet - byte array to test
    
    Returns:
    true if any byte is a valid character in the alphabet or PAD; false otherwise
  - decode
```
public byte[] decode(byte[] pArray)
```
    Decodes a byte[] containing characters in the Base-N alphabet.
    
    Specified by:
    
    decode in interface BinaryDecoder
    
    Parameters:
    pArray - A byte array containing Base-N character data
    
    Returns:
    a byte array containing binary data
  - decode
```
public byte[] decode(byte[] pArray,
            int off,
            int len)
```
  - decode
```
public byte[] decode(String pArray)
```
    Decodes a String containing characters in the Base-N alphabet.
    
    Parameters:
    pArray - A String containing Base-N character data
    
    Returns:
    a byte array containing binary data
  - decode
```
@Deprecated
public Object decode(Object obj)
              throws DecoderException
```
    Deprecated. This unused method will be removed in Tomcat 9
    
    Decodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Decoder interface, and will throw a DecoderException if the supplied object is not of type byte[] or String.
    
    Specified by:
    
    decode in interface Decoder
    
    Parameters:
    obj - Object to decode
    
    Returns:
    An object (of type byte[]) containing the binary data which corresponds to the byte[] or String supplied.
    
    Throws:
    
    DecoderException - if the parameter supplied is not of type byte[]
  - encode
```
public byte[] encode(byte[] pArray)
```
    Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
    
    Specified by:
    
    encode in interface BinaryEncoder
    
    Parameters:
    pArray - a byte array containing binary data
    
    Returns:
    A byte array containing only the base N alphabetic character data
  - encode
```
public byte[] encode(byte[] pArray,
            int offset,
            int length)
```
    Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
    
    Parameters:
    pArray - a byte array containing binary data
    offset - initial offset of the subarray.
    length - length of the subarray.
    
    Returns:
    A byte array containing only the base N alphabetic character data
    Since:
    
    1.11
  - encodeAsString
```
public String encodeAsString(byte[] pArray)
```
    Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet. Uses UTF8 encoding.
    
    Parameters:
    pArray - a byte array containing binary data
    
    Returns:
    String containing only character data in the appropriate alphabet.
    Since:
    
    1.5 This is a duplicate of encodeToString(byte[]); it was merged during refactoring.
  - encode
```
@Deprecated
public Object encode(Object obj)
              throws EncoderException
```
    Deprecated. This unused method will be removed in Tomcat 9
    
    Encodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Encoder interface, and will throw an EncoderException if the supplied object is not of type byte[].
    
    Specified by:
    
    encode in interface Encoder
    
    Parameters:
    obj - Object to encode
    
    Returns:
    An object (of type byte[]) containing the Base-N encoded data which corresponds to the byte[] supplied.
    
    Throws:
    
    EncoderException - if the parameter supplied is not of type byte[]
  - encodeToString
```
public String encodeToString(byte[] pArray)
```
    Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet. Uses UTF8 encoding.
    
    Parameters:
    pArray - a byte array containing binary data
    
    Returns:
    A String containing only Base-N character data
  - ensureBufferSize
```
protected byte[] ensureBufferSize(int size,
                      org.apache.tomcat.util.codec.binary.BaseNCodec.Context context)
```
    Ensure that the buffer has room for size bytes
    
    Parameters:
    size - minimum spare space required
    context - the context to be used
    
    Returns:
    the buffer
  - getDefaultBufferSize
```
protected int getDefaultBufferSize()
```
    Get the default buffer size. Can be overridden.
    
    Returns:
    the default buffer size.
  - getEncodedLength
```
public long getEncodedLength(byte[] pArray)
```
    Calculates the amount of space needed to encode the supplied array.
    
    Parameters:
    pArray - byte[] array which will later be encoded
    
    Returns:
    amount of space needed to encoded the supplied array. Returns a long since a max-len array will require > Integer.MAX_VALUE
  - isInAlphabet
```
protected abstract boolean isInAlphabet(byte value)
```
    Returns whether or not the octet is in the current alphabet. Does not allow whitespace or pad.
    
    Parameters:
    value - The value to test
    
    Returns:
    true if the value is defined in the current alphabet, false otherwise.
  - isInAlphabet
```
public boolean isInAlphabet(byte[] arrayOctet,
                   boolean allowWSPad)
```
    Tests a given byte array to see if it contains only valid characters within the alphabet. The method optionally treats whitespace and pad as valid.
    
    Parameters:
    arrayOctet - byte array to test
    allowWSPad - if true, then whitespace and PAD are also allowed
    
    Returns:
    true if all bytes are valid characters in the alphabet or if the byte array is empty; false, otherwise
  - isInAlphabet
```
public boolean isInAlphabet(String basen)
```
    Tests a given String to see if it contains only valid characters within the alphabet. The method treats whitespace and PAD as valid.
    
    Parameters:
    basen - String to test
    
    Returns:
    true if all characters in the String are valid characters in the alphabet or if the String is empty; false, otherwise
    See Also:
    isInAlphabet(byte[], boolean)

Class BaseNCodec

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

sm

MIME_CHUNK_SIZE

PEM_CHUNK_SIZE

MASK_8BITS

PAD_DEFAULT

pad

lineLength

Constructor Detail

BaseNCodec

BaseNCodec

Method Detail

getChunkSeparator

isWhiteSpace

containsAlphabetOrPad

decode

decode

decode

decode

encode

encode

encodeAsString

encode

encodeToString

ensureBufferSize

getDefaultBufferSize

getEncodedLength

isInAlphabet

isInAlphabet

isInAlphabet