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 java.util.HashSet;
019    import java.util.Map;
020    import java.util.Set;
021    
022    public class MessageUtils {
023        /**
024         * Interpolates a message based on values contained in the data map, assuming message is formatted using a ${key} syntax.
025         *
026         * @param message
027         *            the message to be interpolated
028         * @param data
029         *            Map<String, String> containing the data to be used for interpolation
030         * @return the interpolated message
031         */
032        public static String interpolate(String message, String... data) {
033            if (message != null) {
034                for (int i = 0; i < data.length; i++) {
035                    message = message.replaceAll("\\$\\{" + i + "\\}", "" + escape(data[i]));
036                }
037            }
038            return message;
039        }
040    
041        /**
042         * Interpolates a message based on parameter index, assuming message is formatted using a ${0}..${n} syntax
043         *
044         * @param message
045         *            the message to be interpolated
046         * @param data
047         *            varargs to be used for interpolation
048         * @return the interpolated message
049         */
050        public static String interpolate(String message, Map<String, Object> data) {
051            if (message != null && data != null) {
052                Set<String> fields = findFields(message);
053                for (String s : fields) {
054                    if(data.get(s) != null){
055                            message = message.replaceAll("\\$\\{" + s + "\\}", "" + escape(data.get(s).toString()));
056                    }
057                }
058            }
059            return message;
060        }
061    
062        /**
063         * Interpolates a message which requires only a single property replacement.
064         *
065         * @param message
066         * @param parameter
067         * @param value
068         * @return the interpolated message
069         */
070        public static String interpolate(String message, String parameter, Object value){
071            message = message.replaceAll("\\$\\{" + parameter + "\\}", "" + escape(value.toString()));
072            return message;
073        }
074    
075        /**
076         * Adds an escape to all characters requiring an escape.
077         *
078         * @param input
079         * @return the input string with characters escaped.
080         */
081        private static String escape(String input) {
082            char[] toEscape = {'\\', '$', '.', '*', '+', '?', '|', '(', ')', '[', ']', '{', '}'};
083            for (char c : toEscape) {
084                input = input.replaceAll("\\" + c, "\\\\\\" + c);
085            }
086            return input;
087        }
088    
089        /**
090         * Returns a Set<String> of all interpolation targets (fields) within a String.
091         *
092         * @param input
093         *            the String from which to extract the interpolation targets
094         * @return Set<String> containing the field names of the interpolation targets
095         */
096        public static Set<String> findFields(String input) {
097            Set<String> result = new HashSet<String>();
098            int begin = input.indexOf("${");
099            while (begin != -1) {
100                int end = input.indexOf("}", begin);
101                result.add(input.substring(begin + 2, end));
102                begin = input.indexOf("${", end);
103            }
104            return result;
105        }
106    
107    }