fr.ms.lang.reflect.ImplementationDecorator Maven / Gradle / Ivy

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/*
 * This file is part of Log4Jdbc.
 *
 * Log4Jdbc is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Log4Jdbc is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Log4Jdbc.  If not, see .
 *
 */
package fr.ms.lang.reflect;

import java.lang.reflect.Array;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.List;

import fr.ms.lang.ClassUtils;

/**
 *
 * @see Marco4J
 *
 *
 * @author Marco Semiao
 *
 */
public class ImplementationDecorator implements InvocationHandler {

    private final Object impl;

    private final Object sourceImpl;

    private final ImplementationProxy ip;

    public ImplementationDecorator(final Object impl, final Object sourceImpl, final ImplementationProxy ip) {
	if (ip == null) {
	    throw new NullPointerException();
	}
	this.impl = impl;
	this.sourceImpl = sourceImpl;
	this.ip = ip;
    }

    public Object invoke(final Object proxy, final Method method, final Object[] args) throws Throwable {
	final Object invoke = method.invoke(impl, args);

	final Object createProxy = ip.createProxy(this, invoke);
	if (createProxy != null) {
	    return createProxy;
	}

	if (invoke != null) {
	    final Class clazz = invoke.getClass();
	    final Class returnType = method.getReturnType();
	    final boolean isPrimitive = clazz.isPrimitive() && returnType.isPrimitive();
	    final boolean isInterface = returnType.isInterface();
	    if (!isPrimitive && isInterface) {
		final boolean isArray = returnType.isArray();
		if (isArray) {
		    final Object[] invokes = (Object[]) invoke;
		    if (invokes.length == 0) {
			return invokes;
		    }

		    final List liste = new ArrayList();
		    for (int i = 0; i < invokes.length; i++) {
			final Object invokeOnly = invokes[i];
			final Object wrapObject = createProxy(invokeOnly);
			liste.add(wrapObject);
		    }

		    return liste.toArray((Object[]) Array.newInstance(returnType.getComponentType(), liste.size()));
		} else {
		    final Object wrapObject = createProxy(invoke);
		    return wrapObject;
		}
	    }
	}

	return invoke;
    }

    private Object createProxy(final Object impl) {
	final Class clazz = impl.getClass();
	final ClassLoader classLoader = clazz.getClassLoader();
	final Class[] interfaces = ClassUtils.getAllInterfaces(clazz);

	if (interfaces == null || interfaces.length == 0) {
	    return impl;
	}
	final InvocationHandler ih = new ImplementationDecorator(impl, sourceImpl, ip);

	final Object proxy = Proxy.newProxyInstance(classLoader, interfaces, ih);

	return proxy;
    }

    public Object getSourceImpl() {
	return sourceImpl;
    }

    public static interface ImplementationProxy {
	public Object createProxy(final ImplementationDecorator origine, final Object invoke);
    }
}