1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package util; 19 20 /** 21 * HTML filter utility. 22 * 23 * @author Craig R. McClanahan 24 * @author Tim Tye 25 * @version $Revision: 664175 $ $Date: 2008-06-06 18:43:44 -0400 (Fri, 06 Jun 2008) $ 26 */ 27 28 public final class HTMLFilter { 29 30 31 /** 32 * Filter the specified message string for characters that are sensitive 33 * in HTML. This avoids potential attacks caused by including JavaScript 34 * codes in the request URL that is often reported in error messages. 35 * 36 * @param message The message string to be filtered 37 */ 38 public static String filter(String message) { 39 40 if (message == null) 41 return (null); 42 43 char content[] = new char[message.length()]; 44 message.getChars(0, message.length(), content, 0); 45 StringBuffer result = new StringBuffer(content.length + 50); 46 for (int i = 0; i < content.length; i++) { 47 switch (content[i]) { 48 case '<': 49 result.append("<"); 50 break; 51 case '>': 52 result.append(">"); 53 break; 54 case '&': 55 result.append("&"); 56 break; 57 case '"': 58 result.append("""); 59 break; 60 default: 61 result.append(content[i]); 62 } 63 } 64 return (result.toString()); 65 66 } 67 68 69 } 70