mondrian.util
Class MemoryMonitorFactory

java.lang.Object
  mondrian.util.ObjectFactory<T>
      mondrian.util.ObjectFactory.Singleton<MemoryMonitor>
          mondrian.util.MemoryMonitorFactory

public final class MemoryMonitorFactory
extends ObjectFactory.Singleton<MemoryMonitor>

The MemoryMonitorFactory is used to get the application's MemoryMonitor. The MemoryMonitorFactory is based upon the ObjectFactory.Singleton generic. The MemoryMonitorFactory implementation has a single, default MemoryMonitor per JVM instance which can be overridden using the provided ThreadLocal variable. Normally, this ThreadLocal override should only be used during JUnit testing. The JUnit test, set the ThreadLocal variable to the name of its own implementation of the MemoryMonitor interface and then calls the ObjectFactory getObject method. After doing the test, the ThreadLocal variable should be cleared.

The ObjectFactory.Singleton permits the use of System properties to provide a class name to the factory. This can be used to create a MemoryMonitor that is not the default one. The property name is the MemoryMonitor class name, "mondrian.util.MemoryMonitor".

Since:

Feb 03 2007

Author:

Richard M. Emberson

Nested Class Summary

Nested classes/interfaces inherited from class mondrian.util.ObjectFactory

ObjectFactory.Context, ObjectFactory.Singleton<T>

Field Summary

Fields inherited from class mondrian.util.ObjectFactory.Singleton

singleInstance, testSingleInstance

Method Summary

static void	clearThreadLocalClassName() Clears the class name (regardless of whether a class name was set).
protected boolean	enabled() Returns whether the use of a MemoryMonitor is enabled.
protected String	getClassName() Get the class name set in the ThreadLocal or null.
protected MemoryMonitor	getDefault(Class[] parameterTypes, Object[] parameterValues) The MemoryMonitorFactory's implementation of the ObjectFactory's abstract method which returns the default MemoryMonitor instance.
static MemoryMonitor	getMemoryMonitor() Access the MemoryMonitorFactory instance.
protected StringProperty	getStringProperty() Return the MemoryMonitorFactory
static void	setThreadLocalClassName(String className) Sets the class name of a MemoryMonitor implementation.

Methods inherited from class mondrian.util.ObjectFactory.Singleton

getObject, getTestObject

Methods inherited from class mondrian.util.ObjectFactory

defaultCreationException, getClassName, getObject, getObject, getObject, getObject, removeContext, restoreContext

Methods inherited from class java.lang.Object

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

Method Detail

getMemoryMonitor

public static MemoryMonitor getMemoryMonitor()

Access the MemoryMonitorFactory instance.

Returns:

the MemoryMonitor.

setThreadLocalClassName

public static void setThreadLocalClassName(String className)

Sets the class name of a MemoryMonitor implementation. This should be called (obviously) before calling the MemoryMonitorFactory getMemoryMonitor method to get the MemoryMonitor implementation. Generally, this is only used for testing.

Parameters:

className - Class name

clearThreadLocalClassName

public static void clearThreadLocalClassName()

Clears the class name (regardless of whether a class name was set). When a class name is set using setThreadLocalClassName, the setting whould be done in a try-block and a call to this clear method should be in the finally-clause of that try-block.

enabled

protected boolean enabled()

Returns whether the use of a MemoryMonitor is enabled.

Returns:

true if enabled and false otherwise.

getClassName

protected String getClassName()

Get the class name set in the ThreadLocal or null.

Overrides:

getClassName in class ObjectFactory<MemoryMonitor>

Returns:

class name or null.

getStringProperty

protected StringProperty getStringProperty()

Return the MemoryMonitorFactory

Specified by:

getStringProperty in class ObjectFactory<MemoryMonitor>

Returns:

MemoryMonitorFactory property name

getDefault

protected MemoryMonitor getDefault(Class[] parameterTypes,
                                   Object[] parameterValues)
                            throws CreationException

The MemoryMonitorFactory's implementation of the ObjectFactory's abstract method which returns the default MemoryMonitor instance. For Java4 or if the MemoryMonitorFactory is not enabled then this method returns the "faux" MemoryMonitor implementation, it does nothing. When enabled and for Java5 and above JVMs, and instance of the NotificationMemoryMonitor is returned.

Specified by:

getDefault in class ObjectFactory<MemoryMonitor>

Throws:

CreationException - if the MemoryMonitor can not be created.

Parameters:

parameterTypes - not used

parameterValues - not used

Returns:

MemoryMonitor instance