/*
* Copyright 2011 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.modelmapper.internal;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import net.sf.cglib.core.DefaultNamingPolicy;
import net.sf.cglib.core.NamingPolicy;
import net.sf.cglib.proxy.CallbackFilter;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.NoOp;
import org.modelmapper.internal.util.Primitives;
import org.objenesis.Objenesis;
import org.objenesis.ObjenesisStd;
/**
* Produces proxied instances of mappable types that participate in mapping creation.
*
* @author Jonathan Halterman
*/
class ProxyFactory {
private static final Objenesis OBJENESIS = new ObjenesisStd();
private static final NamingPolicy NAMING_POLICY = new DefaultNamingPolicy() {
@Override
protected String getTag() {
return "ByModelMapper";
}
};
private static final CallbackFilter METHOD_FILTER = new CallbackFilter() {
public int accept(Method method) {
return method.isBridge()
|| method.getDeclaringClass().equals(Object.class)
|| (method.getName().equals("equals") && method.getParameterTypes().length == 1
&& method.getParameterTypes()[0].equals(Object.class) && method.getReturnType()
.equals(Boolean.TYPE))
|| (method.getReturnType().getName().equals("groovy.lang.MetaClass") && (method.getName()
.equals("getMetaClass") || method.getName().startsWith("$"))) ? 1 : 0;
}
};
static Class<?> proxyClassFor(Class<?> type, Errors errors) throws ErrorsException {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(type);
enhancer.setUseFactory(true);
enhancer.setUseCache(true);
enhancer.setNamingPolicy(NAMING_POLICY);
enhancer.setCallbackFilter(METHOD_FILTER);
enhancer.setCallbackTypes(new Class[] { MethodInterceptor.class, NoOp.class });
try {
return enhancer.createClass();
} catch (Throwable t) {
throw errors.errorEnhancingClass(type, t).toException();
}
}
/**
* @throws ErrorsException if the proxy for {@code type} cannot be generated or instantiated
*/
@SuppressWarnings("unchecked")
static <T> T proxyFor(Class<T> type, MethodInterceptor interceptor, Errors errors)
throws ErrorsException {
if (Modifier.isFinal(type.getModifiers()))
return Primitives.defaultValueForWrapper(type);
Class<?> enhanced = proxyClassFor(type, errors);
try {
T result = (T) OBJENESIS.newInstance(enhanced);
setCallbacks(result, interceptor);
return result;
} catch (Throwable t) {
throw errors.errorInstantiatingProxy(type, t).toException();
}
}
private static void setCallbacks(Object enhanced, MethodInterceptor interceptor) throws Exception {
Field callback1 = enhanced.getClass().getDeclaredField("CGLIB$CALLBACK_0");
callback1.setAccessible(true);
callback1.set(enhanced, interceptor);
Field callback2 = enhanced.getClass().getDeclaredField("CGLIB$CALLBACK_1");
callback2.setAccessible(true);
callback2.set(enhanced, NoOp.INSTANCE);
}
}