net.sf.jasperreports.engine.util

Class JRSingletonCache<T>

java.lang.Object

net.sf.jasperreports.engine.util.JRSingletonCache<T>

public class JRSingletonCache<T>
extends Object

Utility to use as a soft cache of singleton instances.

Author:

Lucian Chirita (lucianc@users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field and Description
static String	EXCEPTION_MESSAGE_KEY_CLASS_NOT_COMPATIBLE
static String	EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND
static String	EXCEPTION_MESSAGE_KEY_INSTANCE_ERROR

Constructor Summary

Constructors

Constructor and Description
JRSingletonCache(Class<T> itf) Creates a cache of singleton instances.

Method Summary

Methods

Modifier and Type	Method and Description
protected T	createInstance(String className)
T	getCachedInstance(String className) Returns the singleton instance corresponding to a class.
protected Map<String,T>	getContextInstanceCache()
protected Object	getContextKey()

Methods inherited from class java.lang.Object

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

Field Detail

EXCEPTION_MESSAGE_KEY_CLASS_NOT_COMPATIBLE

public static final String EXCEPTION_MESSAGE_KEY_CLASS_NOT_COMPATIBLE

See Also:

Constant Field Values

EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND

public static final String EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND

See Also:

Constant Field Values

EXCEPTION_MESSAGE_KEY_INSTANCE_ERROR

public static final String EXCEPTION_MESSAGE_KEY_INSTANCE_ERROR

See Also:

Constant Field Values

Constructor Detail

JRSingletonCache

public JRSingletonCache(Class<T> itf)

Creates a cache of singleton instances.

Parameters:

itf - a interface or class that should be implemented by all classes cached by this object

Method Detail

getCachedInstance

public T getCachedInstance(String className)
                    throws JRException

Returns the singleton instance corresponding to a class.

The instance is first searched into the cache and created if not found.

The class is expected to have a no-argument constructor.

Parameters:

className -

Returns:

the singleton instance corresponding to a class

Throws:

JRException

createInstance

protected T createInstance(String className)
                    throws JRException

Throws:

JRException

getContextInstanceCache

protected Map<String,T> getContextInstanceCache()

getContextKey

protected Object getContextKey()