/*

  * Copyright 2007-2008 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);

      }

 }