com.helger.commons.messagedigest

Interface IMessageDigestGenerator

All Known Implementing Classes:

AbstractMessageDigestGenerator, MessageDigestGenerator, NonBlockingMessageDigestGenerator

public interface IMessageDigestGenerator

Base interface for a message digest generator (using hash algorithms like MD5 or SHA 512)

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field and Description
static EMessageDigestAlgorithm	DEFAULT_ALGORITHM The default algorithm that should be used.

Method Summary

Methods

Modifier and Type	Method and Description
String	getAlgorithmName()
byte[]	getAllDigestBytes() Finish calculation of the hash value and return the digest.
byte[]	getAllDigestBytes(int nLength) Get only a part of the digest, namely the first number of bytes.
String	getDigestHexString() This method converts the current hash digest to a hex string.
int	getDigestLength()
long	getDigestLong() This method finalizes the hash generation and creates the index.
Provider	getSecurityProvider()
void	reset() Reset the current hash so that generation can start from scratch again.
IMessageDigestGenerator	update(byte aValue) Update the hash with the given byte.
IMessageDigestGenerator	update(byte[] aValue) Update the hash with the given byte array.
IMessageDigestGenerator	update(byte[] aValue, int nOffset, int nLength) Update the hash with a slice of the given byte array.
IMessageDigestGenerator	update(String sValue, Charset aCharset) Update the hash with the bytes of the given string in the given charset.

Field Detail

DEFAULT_ALGORITHM

static final EMessageDigestAlgorithm DEFAULT_ALGORITHM

The default algorithm that should be used.

Method Detail

getSecurityProvider

@Nonnull
Provider getSecurityProvider()

Returns:

The used security Provider. Should not be null.

getAlgorithmName

@Nonnull
String getAlgorithmName()

Returns:

The name of the hashing algorithm used.

getDigestLength

@Nonnegative
int getDigestLength()

Returns:

Returns the length of the digest in bytes, or 0 if this operation is not supported by the provider.

update

@Nonnull
IMessageDigestGenerator update(byte aValue)

Update the hash with the given byte. After calling getAllDigestBytes() once, no further update is possible.

Parameters:

aValue - The byte value to update the hash

Returns:

this

update

@Nonnull
IMessageDigestGenerator update(@Nonnull
                                     String sValue,
                                     @Nonnull
                                     Charset aCharset)

Update the hash with the bytes of the given string in the given charset. After calling getAllDigestBytes() once, no further update is possible.

Parameters:

sValue - The string value to update the hash. May not be null.

aCharset - The charset to be used for extraction of the bytes. May not be null.

Returns:

this

update

@Nonnull
IMessageDigestGenerator update(@Nonnull
                                     byte[] aValue)

Update the hash with the given byte array. After calling getAllDigestBytes() once, no further update is possible.

Parameters:

aValue - The byte array to update the hash. May not be null.

Returns:

this

update

@Nonnull
IMessageDigestGenerator update(@Nonnull
                                     byte[] aValue,
                                     @Nonnegative
                                     int nOffset,
                                     @Nonnegative
                                     int nLength)

Update the hash with a slice of the given byte array. After calling getAllDigestBytes() once, no further update is possible.

Parameters:

aValue - The byte array to update the hash. May not be null.

nOffset - The offset within the byte array from which the value should be taken. May not be < 0.

nLength - The number of bytes to use, starting from the passed offset. May not be < 0.

Returns:

this

reset

void reset()

Reset the current hash so that generation can start from scratch again.

getAllDigestBytes

@Nonnull
@ReturnsMutableCopy
byte[] getAllDigestBytes()

Finish calculation of the hash value and return the digest. Afterwards no update is possible before reset() is called.

Returns:

A copy of the array with the message digest.

getAllDigestBytes

@Nonnull
@ReturnsMutableCopy
byte[] getAllDigestBytes(@Nonnegative
                                                  int nLength)

Get only a part of the digest, namely the first number of bytes. Calls getAllDigestBytes() internally so no further update is possible after this method is called.

Parameters:

nLength - The number of bytes to be retrieved. Must be > 0.

Returns:

A copy of the first n bytes of the message digest array.

getDigestLong

long getDigestLong()

This method finalizes the hash generation and creates the index. Calls getAllDigestBytes() internally so no further update is possible after this method is called.

Returns:

the generated hash value.

getDigestHexString

@Nonnull
String getDigestHexString()

This method converts the current hash digest to a hex string. Calls getAllDigestBytes() internally so no further update is possible after this method is called.

Returns:

The hex value of the hash digest. Never null.