001    /**
002     * Copyright 2005-2013 The Kuali Foundation
003     *
004     * Licensed under the Educational Community License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.opensource.org/licenses/ecl2.php
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.kuali.rice.krad.util;
017    
018    import org.apache.commons.codec.EncoderException;
019    import org.apache.commons.codec.net.URLCodec;
020    import org.apache.commons.lang.StringUtils;
021    import org.apache.log4j.Logger;
022    
023    import java.util.Properties;
024    
025    /**
026     * This class Provides utility methods for re/building URLs.
027     * 
028     * 
029     */
030    
031    public class UrlFactory {
032        private static Logger LOG = Logger.getLogger(UrlFactory.class);
033        /**
034         * Creates a new URL by taking the given URL and appending the parameter names and values from the given Properties instance to
035         * it. Note: parameter names must be non-blank; parameter values must be non-null.
036         * 
037         * @param baseUrl the URL string used as the basis for reconstruction
038         * @param params Properties instance containing the desired parameters and their values
039         * @throws IllegalArgumentException if the given url is null or empty
040         * @throws IllegalArgumentException if the given Properties instance is null
041         * @throws IllegalArgumentException if a parameter name is null or empty, or a parameter value is null
042         * @throws RuntimeException if there is a problem encoding a parameter name or value into UTF-8
043         * @return a newly-constructed URL string which has the given parameters and their values appended to it
044         */
045        private static URLCodec urlCodec = new URLCodec("UTF-8");
046        
047        public static String parameterizeUrl(String baseUrl, Properties params) {
048            baseUrl = StringUtils.trim(baseUrl);
049            if (StringUtils.isEmpty(baseUrl)) {
050                throw new IllegalArgumentException("invalid (blank) base URL");
051            }
052            if (params == null) {
053                throw new IllegalArgumentException("invalid (null) Properties");
054            }
055    
056    
057            StringBuffer ret = new StringBuffer(baseUrl);
058            // Only start with ? if it has not been added to the url
059            String delimiter = (ret.indexOf("?") == -1) ? "?" : "&";
060            for ( Object key : params.keySet() ) {
061                String paramName = StringUtils.trim( (String)key );
062                String paramValue = params.getProperty(paramName);
063                ret.append( delimiter );
064                if (StringUtils.isEmpty(paramName)) {
065                    throw new IllegalArgumentException("invalid (blank) paramName");
066                }
067                if (paramValue == null) {
068                    ret.append( paramName );
069                    ret.append( "=" );
070                } else {
071                    try {
072                        ret.append( paramName );
073                        ret.append( "=" );
074                        ret.append( urlCodec.encode(paramValue) );
075                    } catch ( EncoderException ex ) {
076                        LOG.error("Unable to encode parameter name or value: " + paramName + "=" + paramValue, ex);
077                        throw new RuntimeException( "Unable to encode parameter name or value: " + paramName + "=" + paramValue, ex );
078                    }
079                }
080                delimiter = "&";
081            }
082    
083            return ret.toString();
084        }
085    
086        public static String encode( String value ) {
087            try {
088                return urlCodec.encode(value);
089            } catch ( EncoderException ex ) {
090                throw new RuntimeException( "Unable to encode value: " + value, ex );
091            }
092        }
093    }