javacard.framework
Interface MultiSelectable

public interface MultiSelectable

The MultiSelectable interface identifies the implementing Applet subclass as being capable of concurrent selections. A multiselectable applet is a subclass of javacard.framework.Applet which directly or indirectly implements this interface. All of the applets within an applet package must be multiselectable. If they are not, then none of the applets can be multiselectable.

An instance of a multiselectable applet can be selected on one logical channel while the same applet instance or another applet instance from within the same package is active on another logical channel.

The methods of this interface are invoked by the Java Card runtime environment only when:

• the same applet instance is still active on another logical channel, or
• another applet instance from the same package is still active on another logical channel.

See Runtime Environment Specification for the Java Card Platform for details.

select

boolean select(boolean appInstAlreadyActive)

Called by the Java Card runtime environment to inform that this applet instance has been selected while the same applet instance or another applet instance from the same package is active on another logical channel.

It is called either when the MANAGE CHANNEL APDU (open) command or the SELECT APDU command is received and before the applet instance is selected. SELECT APDU commands use instance AID bytes for applet selection. See Runtime Environment Specification for the Java Card Platform, section 4.5 for details.

A subclass of Applet should, within this method, perform any initialization that may be required to process APDU commands that may follow. This method returns a boolean to indicate that it is ready to accept incoming APDU commands via its process() method. If this method returns false, it indicates to the Java Card runtime environment that this applet instance declines to be selected.

Note:

• The javacard.framework.Applet.select() method is not called if this method is invoked.

Parameters:

appInstStillActive - boolean flag is true when the same applet instance is already active on another logical channel and false otherwise

deselect

void deselect(boolean appInstStillActive)

Called by the Java Card runtime environment to inform that this applet instance has been selected while the same applet instance or another applet instance from the same package is active on another logical channel.

It is called either when the MANAGE CHANNEL APDU (open) command or the SELECT APDU command is received and before the applet instance is selected. SELECT APDU commands use instance AID bytes for applet selection. See Runtime Environment Specification for the Java Card Platform, section 4.5 for details.

A subclass of Applet should, within this method, perform any initialization that may be required to process APDU commands that may follow. This method returns a boolean to indicate that it is ready to accept incoming APDU commands via its process() method. If this method returns false, it indicates to the Java Card runtime environment that this applet instance declines to be selected.

Note:

• The javacard.framework.Applet.select() method is not called if this method is invoked.

Parameters:

appInstStillActive - boolean flag is true when the same applet instance is still active on another logical channel and false otherwise