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/*******************************************************************************
 * * Copyright 2012 Impetus Infotech.
 *  *
 *  * 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 com.impetus.kundera.utils;

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import javassist.Modifier;

import javax.persistence.Transient;

import com.impetus.kundera.KunderaException;

/**
 * The Class ReflectUtils.
 * 
 * @author animesh.kumar
 */
public class ReflectUtils
{

    /**
     * Instantiates a new reflect utils.
     */
    private ReflectUtils()
    {

    }

    /**
     * Checks for interface "has" in class "in".
     * 
     * @param has
     *            the has
     * @param in
     *            the in
     * 
     * @return true, if exists?
     */
    public static boolean hasInterface(Class has, Class in)
    {
        if (has.equals(in))
        {
            return true;
        }
        boolean match = false;
        for (Class intrface : in.getInterfaces())
        {
            if (intrface.getInterfaces().length > 0)
            {
                match = hasInterface(has, intrface);
            }
            else
            {
                match = intrface.equals(has);
            }

            if (match)
            {
                return true;
            }
        }
        return false;
    }

    /**
     * Gets the type arguments.
     * 
     * @param property
     *            the property
     * 
     * @return the type arguments
     */
    public static Type[] getTypeArguments(Field property)
    {
        Type type = property.getGenericType();
        if (type instanceof ParameterizedType)
        {
            return ((ParameterizedType) type).getActualTypeArguments();
        }
        return null;
    }

    /**
     * Checks for super "has" in class "in".
     * 
     * @param has
     *            the has
     * @param in
     *            the in
     * 
     * @return true, if exists?
     */
    public static boolean hasSuperClass(Class has, Class in)
    {
        if (in.equals(has))
        {
            return true;
        }
        boolean match = false;
        // stop if the superclass is Object
        if (in.getSuperclass() != null && in.getSuperclass().equals(Object.class))
        {
            return match;
        }
        match = in.getSuperclass() != null ? hasSuperClass(has, in.getSuperclass()): false;
        return match;
    }

    /**
     * Loads class with className using classLoader.
     * 
     * @param className
     *            the class name
     * @param classLoader
     *            the class loader
     * @return the class
     */
    public static Class classForName(String className, ClassLoader classLoader)
    {
        try
        {
            Class c = null;
            try
            {
                c = Class.forName(className, true, ReflectUtils.class.getClassLoader());
            }
            catch (ClassNotFoundException e)
            {
                try
                {
                    c = Class.forName(className);
                }
                catch (ClassNotFoundException e1)
                {
                    if (classLoader == null)
                    {
                        throw e1;
                    }
                    else
                    {
                        c = classLoader.loadClass(className);
                    }
                }
            }
            return c;
        }
        catch (ClassNotFoundException e)
        {
            throw new KunderaException(e);
        }
    }

    /**
     * Strip enhancer class.
     * 
     * @param c
     *            the c
     * @return the class
     */
    public static Class stripEnhancerClass(Class c)
    {
        String className = c.getName();

        // strip CGLIB from name
        int enhancedIndex = className.indexOf("$$EnhancerByCGLIB");
        if (enhancedIndex != -1)
        {
            className = className.substring(0, enhancedIndex);
        }

        if (className.equals(c.getName()))
        {
            return c;
        }
        else
        {
            c = classForName(className, c.getClassLoader());
        }
        return c;
    }

    public static boolean isTransientOrStatic(Field field)
    {
        return field != null
                && (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers()) || field
                        .isAnnotationPresent(Transient.class));
    }
}