001/* 002 * Shredzone Commons 003 * 004 * Copyright (C) 2012 Richard "Shred" Körber 005 * http://commons.shredzone.org 006 * 007 * This program is free software: you can redistribute it and/or modify 008 * it under the terms of the GNU Library General Public License as 009 * published by the Free Software Foundation, either version 3 of the 010 * License, or (at your option) any later version. 011 * 012 * This program is distributed in the hope that it will be useful, 013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 015 * GNU General Public License for more details. 016 * 017 * You should have received a copy of the GNU Library General Public License 018 * along with this program. If not, see <http://www.gnu.org/licenses/>. 019 */ 020package org.shredzone.commons.text.filter; 021 022import org.shredzone.commons.text.TextFilter; 023 024/** 025 * Escapes a plain text so it can be safely used in HTML. '<', '&' and '"' are 026 * replaced by their respective HTML entities. 027 * 028 * @author Richard "Shred" Körber 029 */ 030public class HtmlEscapeFilter implements TextFilter { 031 032 @Override 033 public CharSequence apply(CharSequence text) { 034 int len = text.length(); 035 StringBuilder sb = new StringBuilder(len * 11 / 10); 036 for (int ix = 0; ix < len; ix++) { 037 char ch = text.charAt(ix); 038 if (ch == '<') { 039 sb.append("<"); 040 } else if (ch == '&') { 041 sb.append("&"); 042 } else if (ch == '"') { 043 sb.append("""); 044 } else { 045 sb.append(ch); 046 } 047 } 048 return sb; 049 } 050 051}