/*
* *************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
* *************************************************************************************
*/
package com.espertech.esper.event.bean;
import com.espertech.esper.epl.core.EngineImportException;
import com.espertech.esper.epl.core.EngineImportService;
import com.espertech.esper.event.EventBeanManufactureException;
import com.espertech.esper.util.OnDemandSunReflectionFactory;
import net.sf.cglib.reflect.FastClass;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class BeanInstantiatorFactory
{
private static Log log = LogFactory.getLog(BeanInstantiatorFactory.class);
private static final Constructor<Object> SUN_JVM_OBJECT_CONSTRUCTOR;
static
{
Constructor<Object> c = null;
Class<?> reflectionFactoryClass = null;
try
{
c = Object.class.getConstructor((Class[])null);
reflectionFactoryClass = Thread.currentThread().getContextClassLoader()
.loadClass("sun.reflect.ReflectionFactory");
}
catch (Exception e)
{
// ignore
}
SUN_JVM_OBJECT_CONSTRUCTOR = c != null && reflectionFactoryClass != null ? c : null;
}
public static BeanInstantiator makeInstantiator(BeanEventType beanEventType, EngineImportService engineImportService) throws EventBeanManufactureException {
// see if we use a factory method
if (beanEventType.getFactoryMethodName() != null)
{
return resolveFactoryMethod(beanEventType, engineImportService);
}
// find public ctor
EngineImportException ctorNotFoundEx;
try {
engineImportService.resolveCtor(beanEventType.getUnderlyingType(), new Class[0]);
if (beanEventType.getFastClass() != null) {
return new BeanInstantiatorByNewInstanceFastClass(beanEventType.getFastClass());
}
else {
return new BeanInstantiatorByNewInstanceReflection(beanEventType.getUnderlyingType());
}
}
catch (EngineImportException ex) {
ctorNotFoundEx = ex;
}
// not found ctor, see if FastClass can handle
if (beanEventType.getFastClass() != null) {
FastClass fastClass = beanEventType.getFastClass();
try
{
fastClass.newInstance();
return new BeanInstantiatorByNewInstanceFastClass(beanEventType.getFastClass());
}
catch (InvocationTargetException e)
{
String message = "Failed to instantiate class '" + fastClass.getJavaClass().getName() + "', define a factory method if the class has no suitable constructors: " + e.getTargetException().getMessage();
log.debug(message);
}
catch (IllegalArgumentException e)
{
String message = "Failed to instantiate class '" + fastClass.getJavaClass().getName() + "', define a factory method if the class has no suitable constructors";
log.debug(message, e);
}
}
// see if JVM ReflectionFactory (specific to JVM) may handle it
if (SUN_JVM_OBJECT_CONSTRUCTOR != null) {
Constructor ctor = OnDemandSunReflectionFactory.getConstructor(beanEventType.getUnderlyingType(), SUN_JVM_OBJECT_CONSTRUCTOR);
return new BeanInstantiatorByCtor(ctor);
}
throw new EventBeanManufactureException("Failed to find no-arg constructor and no factory method has been configured and cannot use Sun-JVM reflection to instantiate object of type " + beanEventType.getUnderlyingType().getName(), ctorNotFoundEx);
}
private static BeanInstantiator resolveFactoryMethod(BeanEventType beanEventType, EngineImportService engineImportService)
throws EventBeanManufactureException
{
String factoryMethodName = beanEventType.getFactoryMethodName();
int lastDotIndex = factoryMethodName.lastIndexOf('.');
if (lastDotIndex == -1)
{
try
{
Method method = engineImportService.resolveMethod(beanEventType.getUnderlyingType(), factoryMethodName, new Class[0], new boolean[0], new boolean[0]);
if (beanEventType.getFastClass() != null) {
return new BeanInstantiatorByFactoryFastClass(beanEventType.getFastClass().getMethod(method));
}
else {
return new BeanInstantiatorByFactoryReflection(method);
}
}
catch (EngineImportException e)
{
String message = "Failed to resolve configured factory method '" + factoryMethodName +
"' expected to exist for class '" + beanEventType.getUnderlyingType() + "'";
log.info(message, e);
throw new EventBeanManufactureException(message, e);
}
}
String className = factoryMethodName.substring(0, lastDotIndex);
String methodName = factoryMethodName.substring(lastDotIndex + 1);
try
{
Method method = engineImportService.resolveMethod(className, methodName, new Class[0], new boolean[0], new boolean[0]);
if (beanEventType.getFastClass() != null) {
FastClass fastClassFactory = FastClass.create(method.getDeclaringClass());
return new BeanInstantiatorByFactoryFastClass(fastClassFactory.getMethod(method));
}
else {
return new BeanInstantiatorByFactoryReflection(method);
}
}
catch (EngineImportException e)
{
String message = "Failed to resolve configured factory method '" + methodName + "' expected to exist for class '" + className + "'";
log.info(message, e);
throw new EventBeanManufactureException(message, e);
}
}
}