org.apache.hadoop.io
Class MD5Hash

java.lang.Object
  org.apache.hadoop.io.MD5Hash

All Implemented Interfaces:

Comparable, Writable, WritableComparable

public class MD5Hash
extends Object
implements WritableComparable

A Writable for MD5 hash values.

Author:

Doug Cutting

Nested Class Summary

static class

MD5Hash.Comparator A WritableComparator optimized for MD5Hash keys.

Field Summary

static int

MD5_LEN

Constructor Summary

MD5Hash()
Constructs an MD5Hash.

MD5Hash(byte[] digest)
Constructs an MD5Hash with a specified value.

MD5Hash(String hex)
Constructs an MD5Hash from a hex string.

Method Summary

int	compareTo(Object o) Compares this object with the specified object for order.
static MD5Hash	digest(byte[] data) Construct a hash value for a byte array.
static MD5Hash	digest(byte[] data, int start, int len) Construct a hash value for a byte array.
static MD5Hash	digest(String string) Construct a hash value for a String.
static MD5Hash	digest(Text text) Construct a hash value for a String.
boolean	equals(Object o) Returns true iff o is an MD5Hash whose digest contains the same values.
byte[]	getDigest() Returns the digest bytes.
long	halfDigest() Construct a half-sized version of this MD5.
int	hashCode() Returns a hash code value for this object.
static MD5Hash	read(DataInput in) Constructs, reads and returns an instance.
void	readFields(DataInput in) Reads the fields of this object from in.
void	set(MD5Hash that) Copy the contents of another instance into this instance.
void	setDigest(String hex) Sets the digest value from a hex string.
String	toString() Returns a string representation of this object.
void	write(DataOutput out) Writes the fields of this object to out.

Methods inherited from class java.lang.Object

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

Field Detail

MD5_LEN

public static final int MD5_LEN

See Also:

Constant Field Values

Constructor Detail

MD5Hash

public MD5Hash()

Constructs an MD5Hash.

MD5Hash

public MD5Hash(String hex)

Constructs an MD5Hash from a hex string.

MD5Hash

public MD5Hash(byte[] digest)

Constructs an MD5Hash with a specified value.

Method Detail

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Reads the fields of this object from in. For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Throws:

IOException

read

public static MD5Hash read(DataInput in)
                    throws IOException

Constructs, reads and returns an instance.

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Writes the fields of this object to out.

Specified by:

write in interface Writable

Throws:

IOException

set

public void set(MD5Hash that)

Copy the contents of another instance into this instance.

getDigest

public byte[] getDigest()

Returns the digest bytes.

digest

public static MD5Hash digest(byte[] data)

Construct a hash value for a byte array.

digest

public static MD5Hash digest(byte[] data,
                             int start,
                             int len)

Construct a hash value for a byte array.

digest

public static MD5Hash digest(String string)

Construct a hash value for a String.

digest

public static MD5Hash digest(Text text)

Construct a hash value for a String.

halfDigest

public long halfDigest()

Construct a half-sized version of this MD5. Fits in a long

equals

public boolean equals(Object o)

Returns true iff o is an MD5Hash whose digest contains the same values.

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns a hash code value for this object.

Overrides:

hashCode in class Object

compareTo

public int compareTo(Object o)

Compares this object with the specified object for order.

Specified by:

compareTo in interface Comparable

toString

public String toString()

Returns a string representation of this object.

Overrides:

toString in class Object

setDigest

public void setDigest(String hex)

Sets the digest value from a hex string.