Class BaseNCodec
java.lang.Object
org.apache.tomcat.util.codec.binary.BaseNCodec
- All Implemented Interfaces:
- BinaryDecoder,- BinaryEncoder,- Decoder,- Encoder
- Direct Known Subclasses:
- Base64
Abstract superclass for Base-N encoders and decoders.
 
This class is thread-safe.
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Field SummaryFieldsModifier and TypeFieldDescriptionprotected final intChunksize for encoding.protected static final intMask used to extract 8 bits, used in decoding bytesstatic final intMIME chunk size per RFC 2045 section 6.8.protected final bytePad byte.protected static final byteByte used to pad output.static final intPEM chunk size per RFC 1421 section 4.3.2.4.protected static final StringManager
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Constructor SummaryConstructorsModifierConstructorDescriptionprotectedBaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength) NotelineLengthis rounded down to the nearest multiple of the encoded block size.protectedBaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad) NotelineLengthis rounded down to the nearest multiple of the encoded block size.
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Method SummaryModifier and TypeMethodDescriptionprotected booleancontainsAlphabetOrPad(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) Deprecated.This unused method will be removed in Tomcat 9byte[]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.Deprecated.This unused method will be removed in Tomcat 9encodeAsString(byte[] pArray) Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet.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 forsizebytesstatic byte[]Gets a copy of the chunk separator per RFC 2045 section 2.1.protected intGet the default buffer size.longgetEncodedLength(byte[] pArray) Calculates the amount of space needed to encode the supplied array.protected abstract booleanisInAlphabet(byte value) Returns whether or not theoctetis in the current alphabet.booleanisInAlphabet(byte[] arrayOctet, boolean allowWSPad) Tests a given byte array to see if it contains only valid characters within the alphabet.booleanisInAlphabet(String basen) Tests a given String to see if it contains only valid characters within the alphabet.protected static booleanisWhiteSpace(byte byteToCheck) Checks if a byte value is whitespace or not.
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Field Details- 
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MIME_CHUNK_SIZEpublic static final int MIME_CHUNK_SIZEMIME 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:
 
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PEM_CHUNK_SIZEpublic static final int PEM_CHUNK_SIZEPEM 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. 
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MASK_8BITSprotected static final int MASK_8BITSMask used to extract 8 bits, used in decoding bytes- See Also:
 
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PAD_DEFAULTprotected static final byte PAD_DEFAULTByte used to pad output.- See Also:
 
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padprotected final byte padPad byte. Instance variable just in case it needs to vary later.
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lineLengthprotected final int lineLengthChunksize for encoding. Not used when decoding. A value of zero or less implies no chunking of the encoded data. Rounded down to the nearest multiple of encodedBlockSize.
 
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Constructor Details- 
BaseNCodecprotected BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength) NotelineLengthis rounded down to the nearest multiple of the encoded block size. IfchunkSeparatorLengthis 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
 
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BaseNCodecprotected BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad) NotelineLengthis rounded down to the nearest multiple of the encoded block size. IfchunkSeparatorLengthis 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.
 
 
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Method Details- 
getChunkSeparatorpublic 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:
 
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isWhiteSpaceprotected 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
 
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containsAlphabetOrPadprotected 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:
- trueif any byte is a valid character in the alphabet or PAD;- falseotherwise
 
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decodepublic byte[] decode(byte[] pArray) Decodes a byte[] containing characters in the Base-N alphabet.- Specified by:
- decodein interface- BinaryDecoder
- Parameters:
- pArray- A byte array containing Base-N character data
- Returns:
- a byte array containing binary data
 
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decodepublic byte[] decode(byte[] pArray, int off, int len) 
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decodeDecodes 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
 
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decodeDeprecated.This unused method will be removed in Tomcat 9Decodes 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:
- decodein 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[]
 
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encodepublic byte[] encode(byte[] pArray) Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.- Specified by:
- encodein interface- BinaryEncoder
- Parameters:
- pArray- a byte array containing binary data
- Returns:
- A byte array containing only the base N alphabetic character data
 
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encodepublic 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
 
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encodeAsStringEncodes 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.
 
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encodeDeprecated.This unused method will be removed in Tomcat 9Encodes 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:
- encodein 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[]
 
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encodeToStringEncodes 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
 
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ensureBufferSizeprotected byte[] ensureBufferSize(int size, org.apache.tomcat.util.codec.binary.BaseNCodec.Context context) Ensure that the buffer has room forsizebytes- Parameters:
- size- minimum spare space required
- context- the context to be used
- Returns:
- the buffer
 
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getDefaultBufferSizeprotected int getDefaultBufferSize()Get the default buffer size. Can be overridden.- Returns:
- the default buffer size.
 
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getEncodedLengthpublic 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 encode the supplied array. Returns a long since a max-len array will require > Integer.MAX_VALUE
 
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isInAlphabetprotected abstract boolean isInAlphabet(byte value) Returns whether or not theoctetis in the current alphabet. Does not allow whitespace or pad.- Parameters:
- value- The value to test
- Returns:
- trueif the value is defined in the current alphabet,- falseotherwise.
 
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isInAlphabetpublic 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:
- trueif all bytes are valid characters in the alphabet or if the byte array is empty;- false, otherwise
 
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isInAlphabetTests 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:
- trueif all characters in the String are valid characters in the alphabet or if the String is empty;- false, otherwise
- See Also:
 
 
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