/*
* $Id: TextUtil.java 515882 2007-03-08 01:33:04Z rgielen $
*
* Copyright 2006 The Apache Software Foundation.
*
* Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
*
* 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.apache.struts2.views.util;
/**
* This class handles HTML escaping of text.
* It was written and optimized to be as fast as possible.
*
*/
public class TextUtil {
protected static final int MAX_LENGTH = 300;
/**
* We use arrays of char in the lookup table because it is faster
* appending this to a StringBuffer than appending a String
*/
protected static final char[][] _stringChars = new char[MAX_LENGTH][];
static {
// Initialize the mapping table
initMapping();
}
/**
* Call escapeHTML(s, false)
*/
public static final String escapeHTML(String s) {
return escapeHTML(s, false);
}
/**
* Escape HTML.
*
* @param s string to be escaped
* @param escapeEmpty if true, then empty string will be escaped.
*/
public static final String escapeHTML(String s, boolean escapeEmpty) {
int len = s.length();
if (len == 0) {
return s;
}
if (!escapeEmpty) {
String trimmed = s.trim();
if ((trimmed.length() == 0) || ("\"\"").equals(trimmed)) {
return s;
}
}
int i = 0;
// First loop through String and check if escaping is needed at all
// No buffers are copied at this time
do {
int index = s.charAt(i);
if (index >= MAX_LENGTH) {
if (index != 0x20AC) { // If not euro symbol
continue;
}
break;
} else if (_stringChars[index] != null) {
break;
}
} while (++i < len);
// If the check went to the end with no escaping then i should be == len now
// otherwise we must continue escaping for real
if (i == len) {
return s;
}
// We found a character to escape and broke out at position i
// Now copy all characters before that to StringBuffer sb
// Since a char[] will be used for copying we might as well get
// a complete copy of it so that we can use array indexing instead of charAt
StringBuffer sb = new StringBuffer(len + 40);
char[] chars = new char[len];
// Copy all chars from the String s to the chars buffer
s.getChars(0, len, chars, 0);
// Append the first i characters that we have checked to the resulting StringBuffer
sb.append(chars, 0, i);
int last = i;
char[] subst;
for (; i < len; i++) {
char c = chars[i];
int index = c;
if (index < MAX_LENGTH) {
subst = _stringChars[index];
// It is faster to append a char[] than a String which is why we use this
if (subst != null) {
if (i > last) {
sb.append(chars, last, i - last);
}
sb.append(subst);
last = i + 1;
}
}
// Check if it is the euro symbol. This could be changed to check in a second lookup
// table in case one wants to convert more characters in that area
else if (index == 0x20AC) {
if (i > last) {
sb.append(chars, last, i - last);
}
sb.append("€");
last = i + 1;
}
}
if (i > last) {
sb.append(chars, last, i - last);
}
return sb.toString();
}
protected static void addMapping(int c, String txt, String[] strings) {
strings[c] = txt;
}
protected static void initMapping() {
String[] strings = new String[MAX_LENGTH];
addMapping(0x22, """, strings); // "
addMapping(0x26, "&", strings); // &
addMapping(0x3c, "<", strings); // <
addMapping(0x3e, ">", strings); // >
addMapping(0xa1, "¡", strings); //
addMapping(0xa2, "¢", strings); //
addMapping(0xa3, "£", strings); //
addMapping(0xa9, "©", strings); //
addMapping(0xae, "®", strings); //
addMapping(0xbf, "¿", strings); //
addMapping(0xc0, "À", strings); //
addMapping(0xc1, "Á", strings); //
addMapping(0xc2, "Â", strings); //
addMapping(0xc3, "Ã", strings); //
addMapping(0xc4, "Ä", strings); //
addMapping(0xc5, "Å", strings); //
addMapping(0xc6, "Æ", strings); //
addMapping(0xc7, "Ç", strings); //
addMapping(0xc8, "È", strings); //
addMapping(0xc9, "É", strings); //
addMapping(0xca, "Ê", strings); //
addMapping(0xcb, "Ë", strings); //
addMapping(0xcc, "Ì", strings); //
addMapping(0xcd, "Í", strings); //
addMapping(0xce, "Î", strings); //
addMapping(0xcf, "Ï", strings); //
addMapping(0xd0, "Ð", strings); //
addMapping(0xd1, "Ñ", strings); //
addMapping(0xd2, "Ò", strings); //
addMapping(0xd3, "Ó", strings); //
addMapping(0xd4, "Ô", strings); //
addMapping(0xd5, "Õ", strings); //
addMapping(0xd6, "Ö", strings); //
addMapping(0xd7, "×", strings); //
addMapping(0xd8, "Ø", strings); //
addMapping(0xd9, "Ù", strings); //
addMapping(0xda, "Ú", strings); //
addMapping(0xdb, "Û", strings); //
addMapping(0xdc, "Ü", strings); //
addMapping(0xdd, "Ý", strings); //
addMapping(0xde, "Þ", strings); //
addMapping(0xdf, "ß", strings); //
addMapping(0xe0, "à", strings); //
addMapping(0xe1, "á", strings); //
addMapping(0xe2, "â", strings); //
addMapping(0xe3, "ã", strings); //
addMapping(0xe4, "ä", strings); //
addMapping(0xe5, "å", strings); //
addMapping(0xe6, "æ", strings); //
addMapping(0xe7, "ç", strings); //
addMapping(0xe8, "è", strings); //
addMapping(0xe9, "é", strings); //
addMapping(0xea, "ê", strings); //
addMapping(0xeb, "ë", strings); //
addMapping(0xec, "ì", strings); //
addMapping(0xed, "í", strings); //
addMapping(0xee, "î", strings); //
addMapping(0xef, "ï", strings); //
addMapping(0xf0, "ð", strings); //
addMapping(0xf1, "ñ", strings); //
addMapping(0xf2, "ò", strings); //
addMapping(0xf3, "ó", strings); //
addMapping(0xf4, "ô", strings); //
addMapping(0xf5, "õ", strings); //
addMapping(0xf6, "ö", strings); //
addMapping(0xf7, "÷", strings); //
addMapping(0xf8, "ø", strings); //
addMapping(0xf9, "ù", strings); //
addMapping(0xfa, "ú", strings); //
addMapping(0xfb, "û", strings); //
addMapping(0xfc, "ü", strings); //
addMapping(0xfd, "ý", strings); //
addMapping(0xfe, "þ", strings); //
addMapping(0xff, "ÿ", strings); //
for (int i = 0; i < strings.length; i++) {
String str = strings[i];
if (str != null) {
_stringChars[i] = str.toCharArray();
}
}
}
}
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