/**
    * Copyright 2005-2015 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.kcb.util;
  
  import java.lang.reflect.InvocationHandler;
  import java.lang.reflect.Method;
  
  import org.springframework.beans.factory.BeanFactory;
  
  /**
   * Maps accessor invocations to beans in a BeanFactory. 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   *
   */
  public class BeanFactoryInvocationHandler implements InvocationHandler {
       private static final String PREFIX = "get";
  
       private BeanFactory beanFactory;
       
       public BeanFactoryInvocationHandler(BeanFactory beanFactory) {
           this.beanFactory = beanFactory;
       }
  
       public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
           if (args != null && args.length > 0) {
               throw new RuntimeException("BeanFactoryInvocationHandler only serves getters");
           }
           String methodName = method.getName();
           if (!methodName.startsWith(PREFIX)) {
               throw new RuntimeException("BeanFactoryInvocationHandler only serves getters");
           }
           String beanName = methodName.substring(PREFIX.length());
           if (beanName.length() == 0) {
               throw new RuntimeException("Illegal accessor, no bean name specified: " + methodName);
           }
           char firstChar = beanName.charAt(0);
           if (!Character.isLowerCase(firstChar)) {
               beanName = Character.toLowerCase(firstChar) + beanName.substring(1);
           }
           return beanFactory.getBean(beanName);
       }
  }