ds.ov2.util
Class Serializable_array

java.lang.Object
  ds.ov2.util.Serializable_array

All Implemented Interfaces:

APDU_Serializable

Direct Known Subclasses:

APDU_short_array, Bignat_array, Host_modulus, Host_signature, Host_vector, Modulus, Signature

public abstract class Serializable_array
extends Object
implements APDU_Serializable

Abstract class providing the APDU_Serializable interface for arrays of APDU_Serializable's. This abstract class implements the APDU_Serializable interface for data types that contain several APDU_Serializable's of possibly different type or size. Clients only need to override the get_array(), and the is_compatible_with method. Overriding get_length() is necessary for clients that can change their size for testing purposes. Overriding size() is optional. Overriding to_byte_array and from_byte_array makes not much sense, execpt for special purposes, such as performing side effects before serialization starts or after deserialization finshes.

CPP Preprocessing

This class uses the following cpp defines: PACKAGE, PUBLIC, ASSERT

Execution Environment:

host, card

Author:

Hendrik Tews

Version:

$Revision: 1.14 $

Last Commit:

$Date: 2009-06-19 20:37:37 $ by $Author: tews $

Constructor Summary

protected

Serializable_array() Disabled constructor.

Method Summary

short	from_byte_array(short len, short this_index, byte[] byte_array, short byte_index) Deserialization of this object for the OV-chip protocol layer.
protected abstract APDU_Serializable[]	get_array() Array of objects to (de-)serialize.
short	get_length() Length of the serializable array.
boolean	is_compatible_with(Object o) Compatibility check for the OV-chip protocol layer.
short	size() Size in bytes necessary to send or receive this object via the OV-chip protocol layer, see APDU_Serializable.size().
short	to_byte_array(short len, short this_index, byte[] byte_array, short byte_index) Serialization of this object for the OV-chip protocol layer.

Methods inherited from class java.lang.Object

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

Constructor Detail

Serializable_array

protected Serializable_array()

Disabled constructor. Creation possible only for subclasses.

Method Detail

get_array

protected abstract APDU_Serializable[] get_array()

Array of objects to (de-)serialize. This method might get called serveral times per (de-)serializtion. The returned array must contain at least one element. Further it must not contain any null references.

Clients must override this method.

Returns:

array of objects to (de-)serialize

get_length

public short get_length()

Length of the serializable array. This method must be used consistently instead of get_array().length to determine the size of the array returned from get_array(). The returned value must be greater than zero and less than or equal to the actual array size.

The default implementation returns get_array().length. By overriding clients can provide the illusion of a shorter array without the need of reallocating this shorter array.

Returns:

effictive size of the array returned by get_array()

size

public short size()

Size in bytes necessary to send or receive this object via the OV-chip protocol layer, see APDU_Serializable.size(). The default implementation used Misc.length_of_serializable_array to determine the size.

Can be overriden for homegenous arrays that can determine their size more efficiently.

Specified by:

size in interface APDU_Serializable

Returns:

size in bytes

is_compatible_with

public boolean is_compatible_with(Object o)

Compatibility check for the OV-chip protocol layer. See the compatibility check explanations and also APDU_Serializable.is_compatible_with.

The default implementation returns false, which is the right value for all host data types. Card data types must override this method.

Specified by:

is_compatible_with in interface APDU_Serializable

Parameters:

o - actual argument or result

Returns:

true if this (the declared argument or result) is considered binary compatible with o.

to_byte_array

public short to_byte_array(short len,
                           short this_index,
                           byte[] byte_array,
                           short byte_index)

Serialization of this object for the OV-chip protocol layer. See APDU_Serializable.to_byte_array.

Overriding makes little sense, except when side effects must be scheduled before the start or after the end of serialization.

Specified by:

to_byte_array in interface APDU_Serializable

Parameters:

len - available space in byte_array

this_index - number of bytes that have already been written in preceeding calls

byte_array - data array to serialize the state into

byte_index - index in byte_array

Returns:

the number of bytes actually written, except for the case where serialization finished by writing precisely len bytes, in this case len + 1 is returned.

from_byte_array

public short from_byte_array(short len,
                             short this_index,
                             byte[] byte_array,
                             short byte_index)

Deserialization of this object for the OV-chip protocol layer. See APDU_Serializable.from_byte_array.

Overriding makes little sense, except when side effects must be scheduled before the start or after the end of serialization.

Specified by:

from_byte_array in interface APDU_Serializable

Parameters:

len - available data in byte_array

this_index - number of bytes that have already been read in preceeding calls

byte_array - data array to deserialize from

byte_index - index in byte_array

Returns:

the number of bytes actually read, except for the case where deserialization finished by reading precisely len bytes, in this case len + 1 is returned.