org.ungoverned.moduleloader.search.selection
Class SimpleSelectionPolicy

java.lang.Object
  org.ungoverned.moduleloader.search.selection.SimpleSelectionPolicy

All Implemented Interfaces:

java.util.EventListener, ModuleListener, SelectionPolicy

public class SimpleSelectionPolicy
extends java.lang.Object
implements SelectionPolicy, ModuleListener

This class implements a reasonably simple selection policy for the ImportSearchPolicy. When given a choice, this selection policy will always select the newest version of the available candidates to satisfy the import identifier. In the case where a candidate has already been selected for a given import identifier, then the previously selected module will be returned, if possible. If it is not possible to return the previously selected module, then a null is returned. This policy assumes that classes are shared globally.

Constructor Summary

SimpleSelectionPolicy()

Method Summary

void	moduleAdded(ModuleEvent event) This method is called after a module is added to the ModuleManager.
void	moduleRemoved(ModuleEvent event) This method is called after a module is remove from the ModuleManager.
void	moduleReset(ModuleEvent event) This method is called after a module has been reset by the ModuleManager.
Module	select(Module module, java.lang.Object identifier, java.lang.Object version, Module[] candidates, CompatibilityPolicy compatPolicy) Selects a single module to resolve the specified import identifier from the array of compatible candidate modules.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleSelectionPolicy

public SimpleSelectionPolicy()

Method Detail

select

public Module select(Module module,
                     java.lang.Object identifier,
                     java.lang.Object version,
                     Module[] candidates,
                     CompatibilityPolicy compatPolicy)

Selects a single module to resolve the specified import identifier from the array of compatible candidate modules. If the import identifier has not been resolved before, then this selection policy chooses the module that exports the newest version of the import identifer. If the import identifier has been resolved already, then the same module that was chosen before is chosen again. This ensures that all modules use the same version of all exported classes.

Specified by:

select in interface SelectionPolicy

Parameters:

module - the module that is importing the target.

identifier - the identifier of the import target.

version - the version number of the import target.

candidates - array of compatible candidate modules from which to choose.

compatPolicy - the compatibility policy that is being used.

Returns:

the selected module or null if no module can be selected.

moduleAdded

public void moduleAdded(ModuleEvent event)

Description copied from interface: ModuleListener

This method is called after a module is added to the ModuleManager.

Specified by:

moduleAdded in interface ModuleListener

Parameters:

event - the event object containing the event details.

moduleReset

public void moduleReset(ModuleEvent event)

Description copied from interface: ModuleListener

This method is called after a module has been reset by the ModuleManager.

Specified by:

moduleReset in interface ModuleListener

Parameters:

event - the event object containing the event details.

moduleRemoved

public void moduleRemoved(ModuleEvent event)

Description copied from interface: ModuleListener

This method is called after a module is remove from the ModuleManager.

Specified by:

moduleRemoved in interface ModuleListener

Parameters:

event - the event object containing the event details.