Package net.sf.jasperreports.engine.util

Class JRSingletonCache<T>

  • public class JRSingletonCache<T>
extends java.lang.Object
    Utility to use as a soft cache of singleton instances.
    Author:
    Lucian Chirita (lucianc@users.sourceforge.net)

    • Field Detail

      • EXCEPTION_MESSAGE_KEY_CLASS_NOT_COMPATIBLE

        public static final java.lang.String EXCEPTION_MESSAGE_KEY_CLASS_NOT_COMPATIBLE
        See Also:
        Constant Field Values

      • EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND

        public static final java.lang.String EXCEPTION_MESSAGE_KEY_CLASS_NOT_FOUND
        See Also:
        Constant Field Values

      • EXCEPTION_MESSAGE_KEY_INSTANCE_ERROR

        public static final java.lang.String EXCEPTION_MESSAGE_KEY_INSTANCE_ERROR
        See Also:
        Constant Field Values

    • Constructor Detail

      • JRSingletonCache

        public JRSingletonCache​(java.lang.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​(java.lang.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​(java.lang.String className)
                    throws JRException
        Throws:
        JRException

      • getContextInstanceCache

        protected java.util.Map<java.lang.String,​T> getContextInstanceCache()

      • getContextKey

        protected java.lang.Object getContextKey()