javolution.lang

Class Initializer

java.lang.Object

javolution.lang.Initializer

public class Initializer
extends Object

An initializer for all classes loaded by any given class loader.

Initialization of classes at startup (or during bundle activation) ensures a significantly improved worst case execution time especially if the classes has configuration logic to be executed then.

Javolution activator initialize Realtime classes when started. When running outside OSGi the method javolution.osgi.internal.OSGiServices.initializeRealtimeClasses() can be used to that effect..

Class loading can be performed in a lazy manner and therefore some parts of the class loading process may be done on first use rather than at load time. Javolution bundle activator ensure that all its classes are initialized at start up. The following code illustrates how this can be done for any bundle.

 public class MyActivator implements BundleActivator {
     public void start(BundleContext bc) throws Exception {
         Initializer initializer = new Initializer(MyActivator.class.getClassLoader());
         initializer.loadClass(com.foo.internal.UnreferencedClass.class);
             // Load explicitly classes not directly or indirectly referenced.
         ... 
         initializer.initializeLoadedClasses(); // Recursive loading/initialization.
         ... // Continue activation
     }
 }

This utility use reflection to find the classes loaded and may not be supported on all platforms.

Version:

5.1, July 26, 2007

Author:

Jean-Marie Dautelle

Field Summary

Fields

Modifier and Type	Field and Description
static Configurable<Boolean>	SHOW_INITIALIZED Indicates if the class being initialized should be logged (default false).

Constructor Summary

Constructors

Constructor and Description
Initializer(ClassLoader classLoader) Creates an initializer for the specified class loader.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	initializeLoadedClasses() Initializes all the loaded classes.
void	loadClass(Class<?> cls) Loads the specified class (does not perform any initialization).
Class<?>[]	loadedClasses() Returns the classes loaded by the class loader of this initializer or null if not supported by the platform.

Methods inherited from class java.lang.Object

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

Field Detail

SHOW_INITIALIZED

public static final Configurable<Boolean> SHOW_INITIALIZED

Indicates if the class being initialized should be logged (default false).

Constructor Detail

Initializer

public Initializer(ClassLoader classLoader)

Creates an initializer for the specified class loader.

Method Detail

loadedClasses

public Class<?>[] loadedClasses()

Returns the classes loaded by the class loader of this initializer or null if not supported by the platform.

loadClass

public void loadClass(Class<?> cls)

Loads the specified class (does not perform any initialization). This method is typically used to load unreferenced classes.

initializeLoadedClasses

public boolean initializeLoadedClasses()

Initializes all the loaded classes. If the initialization leads to more classes being loaded, these classes are initialized as well (recursive process).

Returns:

true if initialization has been performed successfully; false otherwise.