package com.carmanconsulting.hibiscus.event;
import com.carmanconsulting.hibiscus.event.annotation.OnEvent;
import com.carmanconsulting.hibiscus.event.invoker.EventObjectAppendedInvoker;
import com.carmanconsulting.hibiscus.event.invoker.ExactMatchInvoker;
import com.carmanconsulting.hibiscus.event.types.EventTypeEnum;
import org.apache.commons.lang3.ClassUtils;
import org.apache.commons.proxy.ProxyFactory;
import org.apache.commons.proxy.factory.javassist.JavassistProxyFactory;
import org.hibernate.event.service.spi.EventListenerRegistry;
import java.lang.reflect.Method;
public final class EventListenerUtils
{
//----------------------------------------------------------------------------------------------------------------------
// Fields
//----------------------------------------------------------------------------------------------------------------------
private static final ProxyFactory PROXY_FACTORY = new JavassistProxyFactory();
//----------------------------------------------------------------------------------------------------------------------
// Static Methods
//----------------------------------------------------------------------------------------------------------------------
@SuppressWarnings("unchecked")
private static <T> T createListener(EventTypeEnum eventType, Object targetObject, Method targetMethod)
{
for (Method proxyMethod : eventType.getEventType().baseListenerInterface().getDeclaredMethods())
{
if (isExactMatch(proxyMethod, targetMethod))
{
return (T) PROXY_FACTORY.createInvokerProxy(new ExactMatchInvoker(eventType, targetObject, targetMethod, proxyMethod), new Class[]{eventType.getEventType().baseListenerInterface()});
}
else if(isEventObjectAppendedMatch(proxyMethod, targetMethod))
{
return (T) PROXY_FACTORY.createInvokerProxy(new EventObjectAppendedInvoker(eventType, targetObject, targetMethod, proxyMethod), new Class[] {eventType.getEventType().baseListenerInterface()});
}
}
return null;
}
private static boolean isEventObjectAppendedMatch(Method proxyMethod, Method targetMethod)
{
final Class<?>[] targetParameterTypes = targetMethod.getParameterTypes();
final Class<?>[] proxyParameterTypes = proxyMethod.getParameterTypes();
final int proxyParameterCount = proxyParameterTypes.length;
if(proxyParameterCount == targetParameterTypes.length - 1)
{
Class<?>[] prefix = new Class[proxyParameterCount];
System.arraycopy(targetParameterTypes, 0, prefix, 0, proxyParameterCount);
return ClassUtils.isAssignable(proxyParameterTypes, prefix);
}
return false;
}
private static boolean isExactMatch(Method proxyMethod, Method targetMethod)
{
return ClassUtils.isAssignable(proxyMethod.getParameterTypes(), targetMethod.getParameterTypes());
}
public static void registerAnnotatedListeners(EventListenerRegistry registry, Object targetObject)
{
for (Method targetMethod : targetObject.getClass().getDeclaredMethods())
{
OnEvent onEvent = targetMethod.getAnnotation(OnEvent.class);
if (onEvent != null)
{
registerEventListener(registry, onEvent.value(), targetObject, targetMethod);
}
}
}
@SuppressWarnings("unchecked")
private static <T> void registerEventListener(EventListenerRegistry registry, EventTypeEnum eventType, Object targetObject, Method targetMethod)
{
T listener = createListener(eventType, targetObject, targetMethod);
if (listener != null)
{
registry.appendListeners(eventType.getEventType(), listener);
}
}
//----------------------------------------------------------------------------------------------------------------------
// Constructors
//----------------------------------------------------------------------------------------------------------------------
private EventListenerUtils()
{
}
}