com.vgrs.xcode.idna
Class Idna

java.lang.Object
  com.vgrs.xcode.idna.Idna

public final class Idna
extends java.lang.Object

Implementation of IDNA2008 Protocol

Ultimately the following will be true:
The Race object uses Utf16 as input and output
The Punycode object uses Unicode as input and output

toAscii
1. Application has Unicode data U32
2. Pass the Unicode data to Idna U32
3. Idna tokenizes the data. *U32
4. Idna runs Unicode through IDNA2008 Protocol if the registration protocol is specified. U32
5. Idna encodes the data using an ACE algorithm U32->U16
6. Idna assembles the labels. U16
7. Idna passes the Utf16 back to the application. U16

- It is not trivial to tokenize the labels as Unicode. We have written
a special object to do so, which allows us to avoid decoding to and
from Unicode just for tokenization.

toUnicode
1. Application has Utf16 (probably Ascii) string U16
2. Pass the Utf16 data to Idna. U16
3. Idna tokenizes the data. U16
4. Idna encodes the data in Unicode. U32 <-U16
5. Idna runs Unicode through IDNA2008 Protocol if the registration protocol is specified.
6. Idna decodes the data to Utf-16. U32->U16
7. Idna decodes the data using an ACE algorithm U32 <-U16
8. Idna assembles the labels *U32
9. Idna asserts IDNA2008 Bidi rules if an RTL label is present in the domain if the registration protocol is specified
10. Idna passes the Unicode back to the application. U32

Version:

1.0 Jun 17, 2010

Author:

nchigurupati

Field Summary

static char	ACE_DELIMITER Stores the Unicode character used to delimit domain labels in an ASCII Compatible Encoding sequence.
static boolean	DEFAULT_REGISTRATION_PROTOCOL Indicates whether or not IDNA2008 Protocol rules are applied.
static boolean	DEFAULT_TO_UNICODE_EXCEPTION_FLAG Indicates whether or not to throw XcodeExceptions from the toUnicode method.
static java.lang.String	DELIMITERS Stores the list of IDNA compliant delimiters.
static int[]	INT_DELIMITERS Stores the list of IDNA compliant delimiters.
static int	MAX_DOMAIN_LABEL_LENGTH_IN_OCTETS RFC 1034 imposes a length restriction of 0 to 63 octets per domain label.

Constructor Summary

Idna(Ace ace)
Construct an Idna object for converting data to and from an ASCII compatible form.

Idna(Ace ace, boolean aToUnicodeExceptionFlag)
Construct an Idna object for converting data to and from an ASCII compatible form.

Idna(Ace ace, boolean aToUnicodeExceptionFlag, boolean aIsRegistrationProtocol)
Construct an Idna object for converting data to and from an ASCII compatible form.

Method Summary

char[]	domainToAscii(int[] input) Converts an array of integers to a character array
int[]	domainToUnicode(char[] input) Converts a character array to an integer array
static boolean	isDelimiter(int c) Checks if the input int is a delimiter
static boolean	isDelimiter(java.lang.String s) Checks if the input string is a delimiter

Methods inherited from class java.lang.Object

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

Field Detail

INT_DELIMITERS

public static final int[] INT_DELIMITERS

Stores the list of IDNA compliant delimiters.
This variable is hard coded to the value {0x2e,0x3002,0xff0e,0xff61}

DELIMITERS

public static final java.lang.String DELIMITERS

Stores the list of IDNA compliant delimiters.
This variable is hard coded to the value "\ u 0 0 2 e \ u 3 0 0 2 \ u f f 0 e \ u f f 6 1"

See Also:

Constant Field Values

ACE_DELIMITER

public static final char ACE_DELIMITER

Stores the Unicode character used to delimit domain labels in an ASCII Compatible Encoding sequence.
This variable is hard coded to the value 0x002e .

See Also:

Constant Field Values

MAX_DOMAIN_LABEL_LENGTH_IN_OCTETS

public static final int MAX_DOMAIN_LABEL_LENGTH_IN_OCTETS

RFC 1034 imposes a length restriction of 0 to 63 octets per domain label.
This variable is hard coded to the value 63 .

See Also:

Constant Field Values

DEFAULT_TO_UNICODE_EXCEPTION_FLAG

public static final boolean DEFAULT_TO_UNICODE_EXCEPTION_FLAG

Indicates whether or not to throw XcodeExceptions from the toUnicode method. Any error condition in the execution of the toUnicode operation results in the return of the input. This prevents applications from knowing whether an error occured during the process. The Idna object uses an internal flag to indicate whether an exception should be thrown if an error condition occurs. Setting the internal flag to true will allow an error condition to throw an exception to the calling application. The application can then decide whether or not to continue execution.
This variable takes the value false by default.

See Also:

Constant Field Values

DEFAULT_REGISTRATION_PROTOCOL

public static final boolean DEFAULT_REGISTRATION_PROTOCOL

Indicates whether or not IDNA2008 Protocol rules are applied. By default this value is true.

See Also:

Constant Field Values

Constructor Detail

Idna

public Idna(Ace ace)
     throws XcodeException

Construct an Idna object for converting data to and from an ASCII compatible form.

Parameters:

ace - An Ace object to use during conversion.

Throws:

XcodeException

Idna

public Idna(Ace ace,
            boolean aToUnicodeExceptionFlag)
     throws XcodeException

Construct an Idna object for converting data to and from an ASCII compatible form.

Parameters:

ace - An Ace object to use during conversion.

aToUnicodeExceptionFlag - See the description for the DEFAULT_TO_UNICODE_EXCEPTION_FLAG attibute which stores the default value for this parameter.

Throws:

XcodeException

Idna

public Idna(Ace ace,
            boolean aToUnicodeExceptionFlag,
            boolean aIsRegistrationProtocol)
     throws XcodeException

Construct an Idna object for converting data to and from an ASCII compatible form.

Parameters:

ace - An Ace object to use during conversion.

aToUnicodeExceptionFlag - See the description for the DEFAULT_TO_UNICODE_EXCEPTION_FLAG attibute which stores the default value for this parameter.

aIsRegistrationProtocol - Indicates whether or not IDNA2008 Protocol rules are applied

Throws:

XcodeException

Method Detail

isDelimiter

public static boolean isDelimiter(java.lang.String s)

Checks if the input string is a delimiter

Parameters:

s - a string to check

Returns:

true if the s represents one of the DELIMITERS, false if not

isDelimiter

public static boolean isDelimiter(int c)

Checks if the input int is a delimiter

Parameters:

c - an int to check

Returns:

true if the s represents one of the DELIMITERS, false if not

domainToAscii

public char[] domainToAscii(int[] input)
                     throws XcodeException

Converts an array of integers to a character array

Parameters:

input - an int array

Returns:

a character array

Throws:

XcodeException - if the input is null or empty

domainToUnicode

public int[] domainToUnicode(char[] input)
                      throws XcodeException

Converts a character array to an integer array

Parameters:

input - a character array

Returns:

an int array

Throws:

XcodeException - if the input is null or empty