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Awake FILE is a secure Open Source framework that allows to program very easily file uploads/downloads and RPC through http. File transfers include powerful features like file chunking and automatic recovery mechanism. Security has been taken into account from the design: server side allows to specify strong security rules in order to protect the files and to secure the RPC calls.
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/*
 * This file is part of Awake FILE. 
 * Awake file: Easy file upload & download over HTTP with Java.                                    
 * Copyright (C) 2015,  KawanSoft SAS
 * (http://www.kawansoft.com). All rights reserved.                                
 *                                                                               
 * Awake FILE is free software; you can redistribute it and/or                 
 * modify it under the terms of the GNU Lesser General Public                    
 * License as published by the Free Software Foundation; either                  
 * version 2.1 of the License, or (at your option) any later version.            
 *                                                                               
 * Awake FILE 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             
 * Lesser General Public License for more details.                               
 *                                                                               
 * You should have received a copy of the GNU Lesser General Public              
 * License along with this library; if not, write to the Free Software           
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  
 * 02110-1301  USA
 *
 * Any modifications to this file must keep this entire header
 * intact.
 */
package org.kawanfw.file.reflection;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.SQLException;

/**
 * 
 * Allows to invoke any method. Usage : to invoke a configurator method that is implemented or
 * not.
 * 
 * @author Nicolas de Pomereu
 * 
 */
public class Invoker {

    /**
     * No constructor usage
     */
    protected Invoker() {
    }
    
    /**
     * Invoke a method of a concrete instance with it's parameters.
     * 
     * @param concreteInstance		the the concrete instance 
     * @param methodName 		the method to call
     * @param param 			the parameter values of the method, if any
     * 
     * @return	the method result when invoked, or null if the method is not implemented.
     * 
     * @throws SecurityException
     * @throws NoSuchMethodException
     * @throws IllegalAccessException
     * @throws IllegalArgumentException
     * @throws InvocationTargetException
     */
    public static Object getMethodResult(
	    Object concreteInstance, String methodName, Object... param)
	    throws SecurityException, NoSuchMethodException,
	    IllegalAccessException, IllegalArgumentException,
	    InvocationTargetException {
	
	Class c = concreteInstance.getClass();
	Object obj = getMethodResult(concreteInstance, methodName, c, param);
	return obj;
	
    }

    /**
     * Call recursively the instance or parent instance in order to execute the method.
     * 
     * @param concreteInstance		the  concrete instance
     * @param methodName		the method we want to call
     * @param c				the class or parent class to call
     * @param param 			the parameter values, if any
     * @return	the method result when invoked, or null if the method is not implemented
     * 
     * @throws SecurityException
     * @throws NoSuchMethodException
     * @throws IllegalAccessException
     * @throws IllegalArgumentException
     * @throws InvocationTargetException
     */
    private static Object getMethodResult(Object concreteInstance,
	    String methodName, Class c, Object... param) throws SecurityException,
	    NoSuchMethodException, IllegalAccessException,
	    IllegalArgumentException, InvocationTargetException {
	Method[] allMethods = c.getDeclaredMethods();
	
	boolean methodExists = false;
	
	for (Method m : allMethods) {
	    if (m.getName().equals(methodName)) {
		methodExists = true;
		break;
	    }
	}

	Class[] argTypes = new Class[param.length];
	    
	for (int i = 0; i < param.length; i++) {
	    argTypes[i] = param[i].getClass();
	    
	    if (argTypes[i].getSimpleName().equals("Boolean")) argTypes[i] = boolean.class;
	    if (argTypes[i].getSimpleName().equals("Byte")) argTypes[i] = byte.class;
	    if (argTypes[i].getSimpleName().equals("Character")) argTypes[i] = char.class;
	    if (argTypes[i].getSimpleName().equals("Double")) argTypes[i] = double.class;
	    if (argTypes[i].getSimpleName().equals("Float")) argTypes[i] = float.class;
	    if (argTypes[i].getSimpleName().equals("Integer")) argTypes[i] = int.class;
	    if (argTypes[i].getSimpleName().equals("Long")) argTypes[i] = long.class;
	    if (argTypes[i].getSimpleName().equals("Short")) argTypes[i] = short.class;
	}
	
	if (methodExists) {
	    Method main = c.getDeclaredMethod(methodName, argTypes);
	    Object result = main.invoke(concreteInstance, param);
	    return result;
	} else {
	    // Maybe there is a super class?
	    Class cSuper = c.getSuperclass();

	    if (cSuper == null) {
		return null;
	    }
	    else 
	    {
		return getMethodResult(concreteInstance, methodName, cSuper, param);
	    }
	}
    }

    /**
     * Says it a method is implemented in a class 
     * 
     * @param className		the class name
     * @param methodName	the method name
     * @return	true if the method exists in the class
     * 
     * @throws SQLException	if any Exception occurs, it is wrapped into an SQLException
     */
    public static boolean existsMethod(String className, String methodName) throws SQLException {
        
        Class c = null;
        
        try {
            c = Class.forName(className);
        } catch (Exception e) {
            throw new SQLException(e);
        } 
        
        Method[] allMethods = c.getDeclaredMethods();
        
        boolean methodExists = false;
        
        for (Method m : allMethods) {
            if (m.getName().equals(methodName)) {
        	methodExists = true;
        	break;
            }	    
        }
        
        return methodExists;
    }
}