Package com.docuverse.identicon

Class IdenticonUtil

java.lang.Object

com.docuverse.identicon.IdenticonUtil

public class IdenticonUtil
extends Object

Utility methods useful for implementing identicon functionality. Methods are class methods for convenience.

Key method of interest is getIdenticonCode(java.net.InetAddress) which converts IP address into identicon code.
IMPORTANT: inetSalt value must be set to reasonably long random string prior to invoking this method.

Author:

don

Constructor Summary

Constructors

Constructor	Description
IdenticonUtil()

Method Summary

Modifier and Type	Method	Description
static int	getIdenticonCode(String codeParam, String remoteAddr)	Returns identicon code specified as an input parameter or derived from an IP address.
static int	getIdenticonCode(InetAddress inetAddr)	Returns identicon code for given IP address.
static String	getIdenticonETag(int code, int size, int version)
static int	getIdenticonSize(String param)
static int	getInetMask()	Returns current IP address mask.
static String	getInetSalt()	Returns current inetSalt value.
static void	setInetMask(int inetMask)	Sets current IP address mask.
static void	setInetSalt(String inetSalt)	Sets current inetSalt value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IdenticonUtil

public IdenticonUtil()

Method Detail

getInetMask

public static int getInetMask()

Returns current IP address mask. Default is 0xffffffff.

Returns:

current IP address mask

setInetMask

public static void setInetMask(int inetMask)

Sets current IP address mask. Default is 0xffffffff.

Parameters:

inetMask -

getInetSalt

public static String getInetSalt()

Returns current inetSalt value.

Returns:

the value

setInetSalt

public static void setInetSalt(String inetSalt)

Sets current inetSalt value.

Parameters:

inetSalt -

getIdenticonCode

public static int getIdenticonCode(InetAddress inetAddr)
                            throws Exception

Returns identicon code for given IP address.

Current implementation uses first four bytes of SHA1(int(mask(ip))+salt) where mask(ip) uses inetMask to remove unwanted bits from IP address. Also, since salt is a string for convenience sake, int(mask(ip)) is converetd into a string and combined with inetSalt prior to hashing.

Parameters:

inetAddr - IP address

Returns:

identicon code for inetAddr

Throws:

Exception

getIdenticonCode

public static int getIdenticonCode(String codeParam,
                                   String remoteAddr)

Returns identicon code specified as an input parameter or derived from an IP address.

This method is a convenience method intended to be used by servlets like below:

 int code = IdenticonUtil.getIdenticonCode(request.getParameter("code"), request
                .getRemoteAddr());
 

Parameters:

codeParam - code parameter, if null remoteAddr parameter will be used to determine the value.

remoteAddr - HTTP requester's IP address. Optional if code was specified.

Returns:

the code

getIdenticonSize

public static int getIdenticonSize(String param)

getIdenticonETag

public static String getIdenticonETag(int code,
                                      int size,
                                      int version)