de.innovationgate.wga.modules

Class ModuleRegistry

java.lang.Object

de.innovationgate.wga.modules.ModuleRegistry

public class ModuleRegistry
extends java.lang.Object

A general purpose module registry for WGA The capabilities are:

• Offers a queryable registration for ModuleDefinition objects, which are mapped by their module type and their implementation class. There can be exactly one module definition for a combination of module type and implementation class
• The amount of module types to use is open and can be dynamically extended by defining new implementations of ModuleType
• The registry is able to inject itself into ModuleDefinition instances or even module implementations themselves when they implement RegistryAwareModuleDefinition and RegistryAwareModule respectively. So those module (definitions) can use the registry to do further lookups.
• The registry can also register some arbitrary "context objects", that are needed by registry aware module (definitions) to work. This is a map that is retrievable via getContextObjects()
• The registry can also register "Option Category Definitions" implemented by OptionCategoryDefinition to provide titles and descriptions for the category names that option definitions provide via OptionDefinition.getCategory(). There can be exactly one option category for a combination of category name and module type.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	MODULEREGISTRATORS_RESOURCE The name of the text file resource which should contain a full qualified name of a ModuleRegistrar implementation

Constructor Summary

Constructors

Constructor and Description
ModuleRegistry()

Method Summary

Methods

Modifier and Type	Method and Description
void	addChangeListener(ModuleRegistryChangeListener listener, java.lang.Class<? extends ModuleType> moduleType)
void	addModuleDefinition(ModuleDefinition modDef) Add a module definition to the registry.
void	addOptionCategoryDefinition(OptionCategoryDefinition catDef) Adds an option category definition
void	clearChangeListeners()
ValidationContext	createValidationContext(WGAConfiguration configCopy) Creates a validation context for option validations
java.util.Map<java.lang.Class,java.lang.Object>	getContextObjects() Returns a map of arbitrary context objects that may be needed for registry aware ModuleDefinition implementations or modules themselves to work
ModuleDefinition	getModuleDefinition(java.lang.Class<? extends ModuleType> moduleType, java.lang.Class implClass) Returns a module definition for a givne module type and implementation class
ModuleDefinition	getModuleDefinition(java.lang.Class<? extends ModuleType> moduleType, java.lang.String className) Returns a module definition for a givne module type and implementation class
ModuleDefinition	getModuleDefinition(java.lang.String modType, java.lang.String className) Returns a module definition for a given module type and implementation class
ModuleDefinition	getModuleDefinitionByKey(java.lang.Class<? extends ModuleType> moduleType, java.lang.String regKey) Tries to retrieve a KeyBasedModuleDefinition from registry via it's key
java.util.Map<java.lang.String,ModuleDefinition>	getModulesForType(java.lang.Class<? extends ModuleType> moduleType) Returns the Map that stores all module definitions of a given type.
java.util.Map<java.lang.String,ModuleDefinition>	getModulesForType(java.lang.String moduleTypeClassName)
java.util.Set<java.lang.String>	getModuleTypes()
java.util.Map<java.lang.String,OptionCategoryDefinition>	getOptionCategoriesForType(java.lang.Class<? extends ModuleType> moduleType) Returns the Map that stores all option category definitions for a given module type.
OptionCategoryDefinition	getOptionCategoryDefinition(java.lang.Class<? extends ModuleType> moduleType, java.lang.String key) Returns an option category definition
java.lang.Object	instantiate(java.lang.Class<? extends java.lang.Object> moduleClass) Method to create a module instantiation.
java.lang.Object	instantiate(ModuleDefinition def) Method to create a module instantiation.
void	removeChangeListener(ModuleRegistryChangeListener listener)
void	removeDefinitionsFromLoader(java.lang.String loaderKey)
void	searchModuleDefinitions(java.lang.ClassLoader classLoader) Triggers the search for ModuleRegistrars on the given class loader.
void	searchModuleDefinitions(java.lang.ClassLoader classLoader, java.lang.Iterable<java.net.URLClassLoader> registrarCfgLoaders) Triggers the search for ModuleRegistrars on the given class loader, but only those whose registration configs are on a list of registrar class loaders.

Methods inherited from class java.lang.Object

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

Field Detail

MODULEREGISTRATORS_RESOURCE

public static final java.lang.String MODULEREGISTRATORS_RESOURCE

The name of the text file resource which should contain a full qualified name of a ModuleRegistrar implementation

See Also:

Constant Field Values

Constructor Detail

ModuleRegistry

public ModuleRegistry()

Method Detail

addModuleDefinition

public void addModuleDefinition(ModuleDefinition modDef)

Add a module definition to the registry. If the definition implements RegistryAwareModuleDefinition, this also injects a registry reference via method RegistryAwareModuleDefinition.injectRegistry(ModuleRegistry)

addOptionCategoryDefinition

public void addOptionCategoryDefinition(OptionCategoryDefinition catDef)

Adds an option category definition

removeDefinitionsFromLoader

public void removeDefinitionsFromLoader(java.lang.String loaderKey)

getOptionCategoriesForType

public java.util.Map<java.lang.String,OptionCategoryDefinition> getOptionCategoriesForType(java.lang.Class<? extends ModuleType> moduleType)

Returns the Map that stores all option category definitions for a given module type. Modifying this map also modifies the registration!

Parameters:

moduleType - The type of module for whom the registered option categories are retrieved

Returns:

The map. The keys are option category names. The values are the OptionCategoryDefinitions themselves

getOptionCategoryDefinition

public OptionCategoryDefinition getOptionCategoryDefinition(java.lang.Class<? extends ModuleType> moduleType,
                                                   java.lang.String key)

Returns an option category definition

Parameters:

moduleType - The module type for whom the category was registered

key - The category name as returned by option definitions via OptionDefinition.getCategory()

Returns:

The option category definition or null if nothing is registered

getModulesForType

public java.util.Map<java.lang.String,ModuleDefinition> getModulesForType(java.lang.Class<? extends ModuleType> moduleType)

Returns the Map that stores all module definitions of a given type. Modifying this map also modifies the registration!

Parameters:

moduleType - The type of module

Returns:

The map. The keys are the full qualified names of implementation classes or KEYBASED_MODULE_PREFIX plus key for KeyBasedModuleDefinition instantations. The values are the ModuleDefinitions themselves

getModulesForType

public java.util.Map<java.lang.String,ModuleDefinition> getModulesForType(java.lang.String moduleTypeClassName)

getModuleDefinition

public ModuleDefinition getModuleDefinition(java.lang.String modType,
                                   java.lang.String className)

Returns a module definition for a given module type and implementation class

Parameters:

modType - The full qualified class name of the module type

className - The full qualified class name of the implementation class

Returns:

The definiton or null if there is nothing registered

getModuleDefinition

public ModuleDefinition getModuleDefinition(java.lang.Class<? extends ModuleType> moduleType,
                                   java.lang.String className)

Returns a module definition for a givne module type and implementation class

Parameters:

moduleType - The module type

className - the full qualified name of the implementation class

Returns:

The definiton or null if there is nothing registered

getModuleDefinitionByKey

public ModuleDefinition getModuleDefinitionByKey(java.lang.Class<? extends ModuleType> moduleType,
                                        java.lang.String regKey)

Tries to retrieve a KeyBasedModuleDefinition from registry via it's key

Parameters:

moduleType - The type of module

regKey - The registration key that the module definition returns via KeyBasedModuleDefinition.getRegistrationKey()

Returns:

The module definition or null if nothing is registered

getModuleDefinition

public ModuleDefinition getModuleDefinition(java.lang.Class<? extends ModuleType> moduleType,
                                   java.lang.Class implClass)

Returns a module definition for a givne module type and implementation class

Parameters:

moduleType - The module type

implClass - The implementation class

Returns:

The definiton or null if there is nothing registered

searchModuleDefinitions

public void searchModuleDefinitions(java.lang.ClassLoader classLoader)
                             throws java.io.IOException

Triggers the search for ModuleRegistrars on the given class loader. The method searches for all known text file resources of name "de/innovationgate/wga/modules/registrar.cfg" on the class loader. These files should contain the full qualified name of a ModuleRegistrar implementation which then is instantiated. The method ModuleRegistrar.registerModules(ModuleRegistry) is called so it can register it's known module definitions.

Parameters:

classLoader - The class loader to load registrars from

Throws:

java.io.IOException

searchModuleDefinitions

public void searchModuleDefinitions(java.lang.ClassLoader classLoader,
                           java.lang.Iterable<java.net.URLClassLoader> registrarCfgLoaders)
                             throws java.io.IOException

Triggers the search for ModuleRegistrars on the given class loader, but only those whose registration configs are on a list of registrar class loaders. The method searches for all known text file resources of name "de/innovationgate/wga/modules/registrar.cfg" on the registrarCfgLoaders. However it only searches for these resources right on these class loaders, not on their parent loaders. These files should contain the full qualified name of a ModuleRegistrar implementation which then is instantiated. The method ModuleRegistrar.registerModules(ModuleRegistry) is called so it can register it's known module definitions.

Parameters:

classLoader - The class loader to load registrar and module classes from

registrarCfgLoaders - The class loader to load registrar configurations from.

Throws:

java.io.IOException

createValidationContext

public ValidationContext createValidationContext(WGAConfiguration configCopy)

Creates a validation context for option validations

getContextObjects

public java.util.Map<java.lang.Class,java.lang.Object> getContextObjects()

Returns a map of arbitrary context objects that may be needed for registry aware ModuleDefinition implementations or modules themselves to work

instantiate

public java.lang.Object instantiate(ModuleDefinition def)
                             throws ModuleInstantiationException

Method to create a module instantiation. While modules are obliged to have a default constructor and therefor could be directly instantiated, module instantiation functions SHOULD use this method (or instantiate(Class) to create module instances, because it is capable of injecting the registry to RegistryAwareModules.

Parameters:

def - The definition of the module

Returns:

The module instance

Throws:

ModuleInstantiationException

instantiate

public java.lang.Object instantiate(java.lang.Class<? extends java.lang.Object> moduleClass)
                             throws ModuleInstantiationException

Method to create a module instantiation. While modules are obliged to have a default constructor and therefor could be directly instantiated, module instantiation functions SHOULD use this method (or instantiate(ModuleDefinition) to create module instances, because it is capable of injecting the registry to RegistryAwareModules.

Parameters:

moduleClass - The implementation class of the module

Returns:

The module instance

Throws:

ModuleInstantiationException

getModuleTypes

public java.util.Set<java.lang.String> getModuleTypes()

addChangeListener

public void addChangeListener(ModuleRegistryChangeListener listener,
                     java.lang.Class<? extends ModuleType> moduleType)

clearChangeListeners

public void clearChangeListeners()

removeChangeListener

public void removeChangeListener(ModuleRegistryChangeListener listener)