/*

  * Copyright 2005-2007 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.kns.util;

 import java.util.Properties;

 import org.apache.commons.codec.EncoderException;

 import org.apache.commons.codec.net.URLCodec;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 /**

  * This class Provides utility methods for re/building URLs.

  * 

  * 

  */

 public class UrlFactory {

     private static Logger LOG = Logger.getLogger(UrlFactory.class);

     /**

      * Creates a new URL by taking the given URL and appending the parameter names and values from the given Properties instance to

      * it. Note: parameter names must be non-blank; parameter values must be non-null.

      * 

      * @param baseUrl the URL string used as the basis for reconstruction

      * @param params Properties instance containing the desired parameters and their values

      * @throws IllegalArgumentException if the given url is null or empty

      * @throws IllegalArgumentException if the given Properties instance is null

      * @throws IllegalArgumentException if a parameter name is null or empty, or a parameter value is null

      * @throws RuntimeException if there is a problem encoding a parameter name or value into UTF-8

      * @return a newly-constructed URL string which has the given parameters and their values appended to it

      */

     private static URLCodec urlCodec = new URLCodec("UTF-8");

     public static String parameterizeUrl(String baseUrl, Properties params) {

         baseUrl = StringUtils.trim(baseUrl);

         if (StringUtils.isEmpty(baseUrl)) {

             throw new IllegalArgumentException("invalid (blank) base URL");

         }

         if (params == null) {

             throw new IllegalArgumentException("invalid (null) Properties");

         }

         StringBuffer ret = new StringBuffer(baseUrl);

         String delimiter = "?";

         for ( Object key : params.keySet() ) {

             String paramName = StringUtils.trim( (String)key );

             String paramValue = params.getProperty(paramName);

             ret.append( delimiter );

             if (StringUtils.isEmpty(paramName)) {

                 throw new IllegalArgumentException("invalid (blank) paramName");

             }

             if (paramValue == null) {

                 ret.append( paramName );

                 ret.append( "=" );

             } else {

                 try {

                     ret.append( paramName );

                     ret.append( "=" );

                     ret.append( urlCodec.encode(paramValue) );

                 } catch ( EncoderException ex ) {

                     LOG.error("Unable to encode parameter name or value: " + paramName + "=" + paramValue, ex);

                     throw new RuntimeException( "Unable to encode parameter name or value: " + paramName + "=" + paramValue, ex );

                 }

             }

             delimiter = "&";

         }

         return ret.toString();

     }

     public static String encode( String value ) {

         try {

             return urlCodec.encode(value);

         } catch ( EncoderException ex ) {

             throw new RuntimeException( "Unable to encode value: " + value, ex );

         }

     }

 }