Class ModuleImpl

java.lang.Object

com.sun.enterprise.module.impl.ModuleImpl

All Implemented Interfaces:

Module

public final class ModuleImpl
extends Object
implements Module

A module represents a set of resources accessible to third party modules. Each module has a module definition which defines its name, its list of exported resources and its dependencies to other modules. A module instance stores references to the class loader instances giving access to the module's implementation. A module instance belongs to a ModuleRegistry which can be used to get the list of available modules and/or get particular module implementation. Modules can only satisfy their dependencies within the ModuleRegistry instance they are registered in.

Field Summary

Fields

Modifier and Type	Field	Description
private final List<ModuleImpl>	dependencies
private final HashMap<String,Long>	lastModifieds
private LifecyclePolicy	lifecyclePolicy
private final ArrayList<ModuleChangeListener>	listeners
private final ModuleDefinition	moduleDef
private ModuleClassLoader	privateCL
private WeakReference<ClassLoaderFacade>	publicCL
private final ModulesRegistryImpl	registry	ModulesRegistryImpl that owns this module.
private final Map<String, List<Class>>	serviceClasses	Lazily loaded provider Classes from ModuleMetadata.
private boolean	shared
private ModuleState	state
private boolean	sticky

Constructor Summary

Constructors

Constructor	Description
ModuleImpl(ModulesRegistryImpl registry, ModuleDefinition info)	Creates a new instance of Module

Method Summary

Modifier and Type	Method	Description
void	addImport(Module module)
Module	addImport(ModuleDependency dependency)	Create and add a new module to this module's list of imports.
void	addListener(ModuleChangeListener listener)	Add a new module change listener
void	detach()	Detach this module from its registry.
void	dumpState(PrintStream writer)
protected void	fireChangeEvent()	fires a ModuleChange event to all listeners
ClassLoaderFacade	getClassLoader()	Return the ClassLoader instance associated with this module.
List<Module>	getImports()	Returns the list of imported modules
ModuleMetadata	getMetadata()	Gets the metadata of this module.
ModuleDefinition	getModuleDefinition()	Returns the module definition for this module instance
String	getName()	Short-cut for getModuleDefinition().getName().
(package private) ModuleClassLoader	getPrivateClassLoader()	Return the private class loader for this module.
<T> Iterable<Class<? extends T>>	getProvidersClass(Class<T> serviceClass)
Iterable<Class>	getProvidersClass(String name)
ModulesRegistryImpl	getRegistry()	Returns the registry owning this module
ModuleState	getState()	Returns the module's state
boolean	hasProvider(Class serviceClass)	Returns true if this module has any provider for the given service class.
boolean	isShared()	Returns true if this module is sharable.
boolean	isSticky()	Returns true if the module is sticky.
(package private) List<ActiveDescriptor>	parseInhabitants(String name, List<PopulatorPostProcessor> postProcessors)	Parses all the inhabitants descriptors of the given name in this module.
void	refresh()	Trigger manual refresh mechanism, the module will check all its URLs and generate change events if any of them has changed.
void	removeImport(ModuleImpl module)
void	removeListener(ModuleChangeListener listener)	Unregister a module change listener
void	resolve()	Ensure that this module is resolved.
(package private) void	setShared(boolean sharable)	Sets the sharable flag.
void	setSticky(boolean sticky)	Sets the sticky flag.
void	start()	Forces module startup.
boolean	stop()	Forces module stop.
String	toString()	Return a String representation
void	uninstall()	Removes the module from the registry backing store, the module will need be reinstalled to be loaded.

Methods inherited from class Object

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

Field Details

moduleDef

private final ModuleDefinition moduleDef

publicCL

private WeakReference<ClassLoaderFacade> publicCL

privateCL

private volatile ModuleClassLoader privateCL

serviceClasses

private final Map<String, List<Class>> serviceClasses

Lazily loaded provider Classes from ModuleMetadata. The key is the service class name. We can't use Class because that would cause leaks.

registry

private final ModulesRegistryImpl registry

ModulesRegistryImpl that owns this module. Always non-null.

state

private ModuleState state

dependencies

private final List<ModuleImpl> dependencies

listeners

private final ArrayList<ModuleChangeListener> listeners

lastModifieds

private final HashMap<String,Long> lastModifieds

shared

private boolean shared

sticky

private boolean sticky

lifecyclePolicy

private LifecyclePolicy lifecyclePolicy

Constructor Details

ModuleImpl

ModuleImpl(ModulesRegistryImpl registry,
 ModuleDefinition info)

Creates a new instance of Module

Method Details

getClassLoader

public ClassLoaderFacade getClassLoader()

Return the ClassLoader instance associated with this module. Only designated public interfaces will be loaded and returned by this classloader.

Specified by:

getClassLoader in interface Module

Returns:

the public ClassLoader

getPrivateClassLoader

ModuleClassLoader getPrivateClassLoader()

Return the private class loader for this module. This class loader will be loading all the classes which are not explicitely exported in the module definition

Returns:

the private ClassLoader instance

getModuleDefinition

public ModuleDefinition getModuleDefinition()

Returns the module definition for this module instance

Specified by:

getModuleDefinition in interface Module

Returns:

the module definition

getRegistry

public ModulesRegistryImpl getRegistry()

Returns the registry owning this module

Specified by:

getRegistry in interface Module

Returns:

the registry owning the module

detach

public void detach()

Detach this module from its registry. This does not free any of the loaded resources. Only proper release of all references to the public class loader will ensure module being garbage collected. Detached modules are orphan and will be garbage collected if resources are properly disposed.

Specified by:

detach in interface Module

toString

public String toString()

Return a String representation

Overrides:

toString in class Object

Returns:

a descriptive String about myself

addListener

public void addListener(ModuleChangeListener listener)

Add a new module change listener

Specified by:

addListener in interface Module

Parameters:

listener - the listener

removeListener

public void removeListener(ModuleChangeListener listener)

Unregister a module change listener

Specified by:

removeListener in interface Module

Parameters:

listener - the listener to unregister

fireChangeEvent

protected void fireChangeEvent()

fires a ModuleChange event to all listeners

refresh

public void refresh()

Trigger manual refresh mechanism, the module will check all its URLs and generate change events if any of them has changed. This will allow the owning registry to force a module upgrade at next module request.

Specified by:

refresh in interface Module

getMetadata

public ModuleMetadata getMetadata()

Gets the metadata of this module.

Specified by:

getMetadata in interface Module

parseInhabitants

List<ActiveDescriptor> parseInhabitants(String name,
 List<PopulatorPostProcessor> postProcessors)
                                 throws IOException

Parses all the inhabitants descriptors of the given name in this module.

Returns:

Throws:

IOException

resolve

public void resolve()
             throws ResolveError

Ensure that this module is resolved.

If the module is already resolved, this method does nothing. Otherwise, iterate over all declared ModuleDependency instances and use the associated ModuleRegistry to resolve it. After successful completion of this method, the module state is ModuleState.RESOLVED.

Specified by:

resolve in interface Module

Throws:

ResolveError - if any of the declared dependency of this module cannot be satisfied

start

public void start()
           throws ResolveError

Forces module startup. In most cases, the runtime will take care of starting modules when they are first used. There could be cases where code need to manually start a sub module. Invoking this method will move the module to the ModuleState.READY, the Lifecycle.start method will be invoked.

Specified by:

start in interface Module

Throws:

ResolveError

stop

public boolean stop()

Forces module stop. In most cases, the runtime will take care of stopping modules when the last module user released its interest. However, in certain cases, it may be interesting to manually stop the module. Stopping the module means that the module is removed from the registry, the class loader references are released (note : the class loaders will only be released if all instances of any class loaded by them are gc'ed). If a LifecyclePolicy for this module is defined, the Lifecycle.stop(Module) method will be called and finally the module state will be returned to ModuleState.NEW.

Specified by:

stop in interface Module

Returns:

true if unloading was successful

getImports

public List<Module> getImports()

Returns the list of imported modules

Specified by:

getImports in interface Module

Returns:

the list of imported modules

addImport

public Module addImport(ModuleDependency dependency)

Create and add a new module to this module's list of imports.

Specified by:

addImport in interface Module

Parameters:

dependency - new module's definition

getState

public ModuleState getState()

Returns the module's state

Specified by:

getState in interface Module

Returns:

the module's state

addImport

public void addImport(Module module)

Specified by:

addImport in interface Module

removeImport

public void removeImport(ModuleImpl module)

getName

public String getName()

Short-cut for getModuleDefinition().getName().

Specified by:

getName in interface Module

isShared

public boolean isShared()

Returns true if this module is sharable. A sharable module means that onlu one instance of the module classloader will be used by all users.

Specified by:

isShared in interface Module

Returns:

true if this module is sharable.

setShared

void setShared(boolean sharable)

Sets the sharable flag. Setting the flag to false means that the moodule class loader should not be shared among module owners.

Parameters:

sharable - set to true to share the module

isSticky

public boolean isSticky()

Returns true if the module is sticky. A sticky module cannot be stopped or unloaded. Once a sticky module is loaded or started, it will stay in the JVM until it exists.

Specified by:

isSticky in interface Module

Returns:

true is the module is sticky

setSticky

public void setSticky(boolean sticky)

Sets the sticky flag.

Specified by:

setSticky in interface Module

Parameters:

sticky - true if the module should stick around

getProvidersClass

public <T> Iterable<Class<? extends T>> getProvidersClass(Class<T> serviceClass)

Specified by:

getProvidersClass in interface Module

getProvidersClass

public Iterable<Class> getProvidersClass(String name)

Specified by:

getProvidersClass in interface Module

hasProvider

public boolean hasProvider(Class serviceClass)

Returns true if this module has any provider for the given service class.

Specified by:

hasProvider in interface Module

dumpState

public void dumpState(PrintStream writer)

Specified by:

dumpState in interface Module

uninstall

public void uninstall()

Description copied from interface: Module

Removes the module from the registry backing store, the module will need be reinstalled to be loaded.

Specified by:

uninstall in interface Module