/*

  * This software is licensed under the Apache License, Version 2.0

  * (the "License") agreement; 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 net.admin4j.util;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Enumeration;

 import java.util.List;

 import javax.servlet.ServletConfig;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpSession;

 import net.admin4j.deps.commons.lang3.StringUtils;

 /**

  * Generic Servlet utilities

  * @author D. Ashmore

  *

  */

 public class ServletUtils {

     /**

      * Will rethrow a caught Servlet Exception

      * @param t

      * @throws ServletException

      * @throws IOException

      */

     public static void reThrowServletFilterException(Throwable t) throws ServletException,

             IOException {

         if (t instanceof ServletException) {

             throw (ServletException)t;

         }

         if (t instanceof IOException) {

             throw (IOException) t;

         }

         if (t instanceof RuntimeException) {

             throw (RuntimeException) t;

         }

         throw new ServletException(t);

     }

     /**

      * Will format session attributes as NavmeValuePairs.

      * @param session

      * @return

      */

     @SuppressWarnings("rawtypes")

     public static List<NameValuePair> listSessionAttributes(HttpSession session) {

         List<NameValuePair> list = new ArrayList<NameValuePair>();

             Enumeration attrNames = session.getAttributeNames();

             String name;

         Object value;

             while (attrNames.hasMoreElements()) {

                     name = (String)attrNames.nextElement();

                     value = session.getAttribute(name);

                     list.add(new NameValuePair(name, value.toString()));

             }

             return list;

     }

     /**

      * Will format request attributes as NameValuePairs.

      * @param request

      * @return

      */

     @SuppressWarnings("rawtypes")

     public static List<NameValuePair> listRequestAttributes(HttpServletRequest request) {

             List<NameValuePair> list = new ArrayList<NameValuePair>();

             Enumeration parmNames = request.getParameterNames();

             String name;

             Object value;

             while (parmNames.hasMoreElements()) {

                     name = (String)parmNames.nextElement();

                     if ("javax.faces.ViewState".equals(name))

                     {

                             value = "[suppressed]";

                     }

                     else

                     {

                             value = request.getParameter(name);

                     }

                     list.add(new NameValuePair(name, value.toString()));

             }

             return list;

     }

     /**

      * Will parse the request and return the name of the current web application.

      * @param request

      * @return

      */

     public static String getApplicationName(HttpServletRequest request) {

             return request.getRequestURI().substring(1, request.getRequestURI().indexOf("/", 1));

     }

     /**

      * Will return the configuration setting requested *in the order of the keys provided*.  The

      * first key to retrieve a non-empty value will be the value returned.

      * @param settingKeysInPrecedenceOrder

      * @param config

      * @return

      */

     public static String getConfigurationSetting(String[] settingKeysInPrecedenceOrder, ServletConfig config) {

         String value = null;

         for (String key: settingKeysInPrecedenceOrder) {

             value = config.getInitParameter(key);

             if (!StringUtils.isEmpty(value)) {

                 return value;

             }

         }

         return value;

     }

 }