com.starteam.util
Class MD5

java.lang.Object
  com.starteam.util.MD5

All Implemented Interfaces:

java.io.Serializable

public final class MD5
extends java.lang.Object
implements java.io.Serializable

A 16 byte hash that uniquely identifies content across space and time

See Also:

Serialized Form

Nested Class Summary

static class

MD5.Stream The MD5 of content digested from a stream, computed after the stream is closed

Constructor Summary

MD5()
Construct an MD5

MD5(byte[] aSourceBytes)
This constructor is expecting (previously computed) MD5 bytes themselves.

MD5(MD5 aMD5)
Construct an MD5 from another

MD5(java.lang.String stringMD5)
Construct a new MD5 with the given String value.

Method Summary

void	computeBufferMD5(byte[] data) Compute MD5 for a byte array.
long	computeFileMD5(java.io.File file) Compute MD5 on a file and return file length.
long	computeStreamMD5(java.io.InputStream in) Compute MD5 on a file and return file length.
boolean	equals(java.lang.Object obj) Return true if the given byte[] is identical to this object.
byte[]	getData() Return the byte[] of this object's value.
int	hashCode() Return a hashcode for this MD5 value.
void	setData(byte[] aSource) set the data (payload) of an MD5 - this is a precomputed MD5 byte array
java.lang.String	toHexString() Return the a 32-character String equal to the hex equivalent of this MD5 value.
java.lang.String	toString() returns a quasi-readable string representation of this MD5

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MD5

public MD5()

Construct an MD5

MD5

public MD5(byte[] aSourceBytes)

This constructor is expecting (previously computed) MD5 bytes themselves. If you need to construct an MD5 for given content, you should be using computeBufferMD5(byte[]).

Parameters:

aSourceBytes - byte[] from previously computed MD5 bytes

MD5

public MD5(MD5 aMD5)

Construct an MD5 from another

Parameters:

aMD5 - another MD5

MD5

public MD5(java.lang.String stringMD5)

Construct a new MD5 with the given String value.

Parameters:

stringMD5 - A 32-character hex value of an MD5 value.

Throws:

java.lang.IllegalArgumentException - If the given value is not 32 characters.

NumberFormatExcpetion - If the given value does not contain all hexadecimal characters (a-z, A-Z, or 0-9).

Method Detail

hashCode

public int hashCode()

Return a hashcode for this MD5 value. Uses the same algorithm as String.hashCode().

Overrides:

hashCode in class java.lang.Object

Returns:

A hash code that distributes nicely based on this object's content, which makes it suitable for hash tables, etc.

equals

public boolean equals(java.lang.Object obj)

Return true if the given byte[] is identical to this object.

Overrides:

equals in class java.lang.Object

Parameters:

obj - Object to be compared.

Returns:

True if the given object is an MD5 object with the same MD5 value.

computeBufferMD5

public void computeBufferMD5(byte[] data)

Compute MD5 for a byte array.

Parameters:

data - the byte[] to compute and encode into an MD5

toHexString

public java.lang.String toHexString()

Return the a 32-character String equal to the hex equivalent of this MD5 value.

Returns:

A 32-character String equal to the hex equivalent of this MD5 value.

toString

public java.lang.String toString()

returns a quasi-readable string representation of this MD5

Overrides:

toString in class java.lang.Object

Returns:

String a quasi-readable string representation of this MD5

computeStreamMD5

public long computeStreamMD5(java.io.InputStream in)
                      throws java.io.IOException

Compute MD5 on a file and return file length.

Parameters:

in - an input stream

Returns:

the length of the file

Throws:

java.io.IOException

computeFileMD5

public long computeFileMD5(java.io.File file)
                    throws java.io.IOException

Compute MD5 on a file and return file length.

Parameters:

file - the file whose md5 is to be computed

Returns:

the file length

Throws:

java.io.IOException

getData

public byte[] getData()

Return the byte[] of this object's value.

Returns:

The 16-byte array containing this object's raw binary value.

setData

public void setData(byte[] aSource)

set the data (payload) of an MD5 - this is a precomputed MD5 byte array

Parameters:

aSource - the MD5