Package org.jboss.modules

Class ModuleLoader

java.lang.Object
org.jboss.modules.ModuleLoader
Direct Known Subclasses:
ClassifyingModuleLoader, ClassPathModuleLoader, JarModuleLoader, LocalModuleLoader
public class ModuleLoader extends Object
A repository for modules, from which a module may be loaded by identifier. Module loaders may additionally delegate to one or more other module loaders.

  • Field Details

  • Constructor Details

    • ModuleLoader

      ModuleLoader(boolean canRedefine, boolean skipRegister)

    • ModuleLoader

      ModuleLoader(boolean canRedefine, boolean skipRegister, ModuleFinder[] finders)

    • ModuleLoader

      protected ModuleLoader()
      Construct a new instance.

    • ModuleLoader

      public ModuleLoader(ModuleFinder[] finders)
      Construct a new instance.
      Parameters:
      finders - the module finders to search, in order

  • Method Details

    • safeClone

      private static ModuleFinder[] safeClone(ModuleFinder[] finders)

    • checkPermissions

      private static boolean checkPermissions()

    • forClass

      public static ModuleLoader forClass(Class<?> clazz)
      Get the module loader for a class.
      Parameters:
      clazz - the class
      Returns:
      the module loader or null if the class's class loader does not belong to a module loader.

    • forClassLoader

      public static ModuleLoader forClassLoader(ClassLoader classLoader)
      Get the module loader for a class loader.
      Parameters:
      classLoader - the class loader
      Returns:
      the module loader or null if the class loader does not belong to a module loader.

    • toString

      public String toString()
      Get the string representation of this module loader.
      Overrides:
      toString in class Object
      Returns:
      the string representation

    • installMBeanServer

      static void installMBeanServer()

    • loadModule

      public final Module loadModule(ModuleIdentifier identifier) throws ModuleLoadException
      Load a module based on an identifier. This method delegates to preloadModule(ModuleIdentifier) and then links the returned module if necessary.
      Parameters:
      identifier - The module identifier
      Returns:
      The loaded Module
      Throws:
      ModuleLoadException - if the Module can not be loaded

    • iterateModules

      public final Iterator<ModuleIdentifier> iterateModules(ModuleIdentifier baseIdentifier, boolean recursive)
      Iterate the modules which can be located via this module loader.
      Parameters:
      baseIdentifier - the identifier to start with, or null to iterate all modules
      recursive - true to find recursively nested modules, false to only find immediately nested modules
      Returns:
      an iterator for the modules in this module finder
      Throws:
      SecurityException - if the caller does not have permission to iterate module loaders

    • preloadModule

      protected Module preloadModule(ModuleIdentifier identifier) throws ModuleLoadException
      Preload a module based on an identifier. By default, no delegation is done and this method simply invokes loadModuleLocal(ModuleIdentifier). A delegating module loader may delegate to the appropriate module loader based on loader-specific criteria (via the preloadModule(ModuleIdentifier, ModuleLoader) method).
      Parameters:
      identifier - the module identifier
      Returns:
      the load result, or null if the module is not found
      Throws:
      ModuleLoadException - if an error occurs

    • preloadExportedModule

      protected Module preloadExportedModule(ModuleIdentifier identifier) throws ModuleLoadException
      Preload an "exported" module based on an identifier. By default this simply delegates to preloadModule(ModuleIdentifier).
      Parameters:
      identifier - the module identifier
      Returns:
      the load result, or null if the module is not found
      Throws:
      ModuleLoadException - if an error occurs

    • preloadModule

      protected static Module preloadModule(ModuleIdentifier identifier, ModuleLoader moduleLoader) throws ModuleLoadException
      Utility method to delegate to another module loader, accessible from subclasses. The delegate module loader will be queried for exported modules only.
      Parameters:
      identifier - the module identifier
      moduleLoader - the module loader to delegate to
      Returns:
      the delegation result
      Throws:
      ModuleLoadException - if an error occurs

    • loadModuleLocal

      protected final Module loadModuleLocal(ModuleIdentifier identifier) throws ModuleLoadException
      Try to load a module from this module loader. Returns null if the module is not found. The returned module may not yet be resolved. The returned module may have a different name than the given identifier if the identifier is an alias for another module.
      Parameters:
      identifier - the module identifier
      Returns:
      the module
      Throws:
      ModuleLoadException - if an error occurs while loading the module

    • findLoadedModuleLocal

      protected final Module findLoadedModuleLocal(ModuleIdentifier identifier)
      Find an already-loaded module, returning null if the module isn't currently loaded. May block while the loaded state of the module is in question (if the module is being concurrently loaded from another thread, for example).
      Parameters:
      identifier - the module identifier
      Returns:
      the module, or null if it wasn't found

    • unloadModuleLocal

      protected final void unloadModuleLocal(Module module) throws SecurityException
      Unload a module from this module loader. Note that this has no effect on existing modules which refer to the module being unloaded. Also, only modules from the current module loader can be unloaded. Unloading the same module more than once has no additional effect. This method only removes the mapping for the module; any running threads which are currently accessing or linked to the module will continue to function, however attempts to load this module will fail until a new module is loaded with the same name. Once this happens, if all references to the previous module are not cleared, the same module may be loaded more than once, causing possible class duplication and class cast exceptions if proper care is not taken.
      Parameters:
      module - the module to unload
      Throws:
      SecurityException - if an attempt is made to unload a module which does not belong to this module loader
      SecurityException - if the module was not defined by this module loader

    • findModule

      protected ModuleSpec findModule(ModuleIdentifier moduleIdentifier) throws ModuleLoadException
      Find a Module's specification in this ModuleLoader by its identifier. This can be overriden by sub-classes to implement the Module loading strategy for this loader. The default implementation iterates the module finders provided during construction.

      If no module is found in this module loader with the given identifier, then this method should return null. If the module is found but some problem occurred (for example, a transitive dependency failed to load) then this method should throw a ModuleLoadException of the relevant type.

      Parameters:
      moduleIdentifier - the module identifier
      Returns:
      the module specification, or null if no module is found with the given identifier
      Throws:
      ModuleLoadException - if any problems occur finding the module

    • getFinders

      protected final ModuleFinder[] getFinders()
      Get the module finders configured for this module loader.
      Returns:
      the module finders

    • defineModule

      private Module defineModule(ConcreteModuleSpec moduleSpec, ModuleLoader.FutureModule futureModule) throws ModuleLoadException
      Defines a Module based on a specification. May only be called from loadModuleLocal(ModuleIdentifier).
      Parameters:
      moduleSpec - The module specification to create the Module from
      futureModule - the future module to populate
      Returns:
      The defined Module
      Throws:
      ModuleLoadException - If any dependent modules can not be loaded

    • refreshResourceLoaders

      protected void refreshResourceLoaders(Module module)
      Refreshes the paths provided by resource loaders associated with the specified Module. This is an advanced method that is intended to be called on modules that have a resource loader implementation that has changed and is returning different paths.
      Parameters:
      module - the module to refresh
      Throws:
      SecurityException - if the module was not defined by this module loader, or if the module loader does not have the required permissions associated with it

    • setAndRefreshResourceLoaders

      protected void setAndRefreshResourceLoaders(Module module, Collection<ResourceLoaderSpec> loaders)
      Replaces the resources loaders for the specified module and refreshes the internal path list that is derived from the loaders. This is an advanced method that should be used carefully, since it alters a live module. Modules that import resources from the specified module will not automatically be updated to reflect the change. For this to occur relink(Module) must be called on all of them.
      Parameters:
      module - the module to update and refresh
      loaders - the new collection of loaders the module should use
      Throws:
      SecurityException - if the module was not defined by this module loader, or if the module loader does not have the required permissions associated with it

    • relink

      protected void relink(Module module) throws ModuleLoadException
      Relinks the dependencies associated with the specified Module. This is an advanced method that is intended to be called on all modules that directly or indirectly import dependencies that are re-exported by a module that has recently been updated and relinked via setAndRelinkDependencies(Module, java.util.List).
      Parameters:
      module - the module to relink
      Throws:
      ModuleLoadException - if relinking failed
      SecurityException - if the module was not defined by this module loader, or if the module loader does not have the required permissions associated with it

    • setAndRelinkDependencies

      protected void setAndRelinkDependencies(Module module, List<DependencySpec> dependencies) throws ModuleLoadException
      Replaces the dependencies for the specified module and relinks against the new modules This is an advanced method that should be used carefully, since it alters a live module. Modules that import dependencies that are re-exported from the specified module will not automatically be updated to reflect the change. For this to occur relink(Module) must be called on all of them.
      Parameters:
      module - the module to update and relink
      dependencies - the new dependency list
      Throws:
      ModuleLoadException - if relinking failed
      SecurityException - if the module was not defined by this module loader, or if the module loader does not have the required permissions associated with it

    • getDependencies

      protected DependencySpec[] getDependencies(Module module)
      Get the current dependency list for a module which was defined by this module loader, without any access checks.
      Returns:
      the current dependency list for the module
      Throws:
      SecurityException - if the module was not defined by this module loader

    • addLinkTime

      void addLinkTime(long amount)

    • addClassLoadTime

      void addClassLoadTime(long time)

    • incScanCount

      void incScanCount()

    • incRaceCount

      void incRaceCount()

    • incClassCount

      void incClassCount()