fdda.utils
Class ObjectCache

java.lang.Object
  |
  +--fdda.utils.ObjectCache

public class ObjectCache

extends Object

The instance of this class (Singleton) caches instances of the classes that have to be loaded dynamically (via Class.forName()). The loaded class itself is also cached, in case of the need for several new instances. The cache is not thread-safe.

Author:

Jörg Rüdenauer

See Also:

Class

Constructor Summary

protected

ObjectCache() The default constructor.

Method Summary

static ObjectCache	getInstance() Returns the instance of ObjectCache (Singleton-Pattern).
Object	getObject(String className) Returns an instance of a dynamically loaded class.
Class	loadClass(String className) Loads a class dynamically, if it isn't cached.

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectCache

protected ObjectCache()

The default constructor.

Method Detail

getInstance

public static ObjectCache getInstance()

Returns the instance of ObjectCache (Singleton-Pattern).

Returns:

the single instance of the class.

loadClass

public final Class loadClass(String className)
                      throws ClassNotFoundException

Loads a class dynamically, if it isn't cached. If it is cached (i.e., was already loaded once), the cached class is returned.

Parameters:

className - the name of the class

Returns:

the loaded class

Throws:

ClassNotFoundException - if the class doesn't exist in the CLASSPATH

getObject

public final Object getObject(String className)
                       throws ClassNotFoundException,
                              InstantiationException,
                              IllegalAccessException

Returns an instance of a dynamically loaded class. If an instance of the class is cached, the cached instance is returned; otherwise, a new instance is created and cached. That means that this method should only be used for classes that are used Singleton-like in the application. The class must have a public constructor without parameters.

Parameters:

className - the name of the class

Returns:

an instance of the class - may already be used!

Throws:

ClassNotFoundException - if the class doesn't exist in the CLASSPATH

InstantiationException - if no instance of the class can be created

IllegalAccessException - if no default constructor is available