import java.util.regex.Pattern
/**
* <p>
* Title: HTML相关的正则表达式工具类
* </p>
* <p>
* Description: 包括过滤HTML标记，转换HTML标记，替换特定HTML标记
* </p>
* <p>
* Copyright: Copyright (c) 2006
* </p>
*
* @author hejian
* @version 1.0
* @createtime 2006-10-16
*/
public class HtmlRegexpUtil {
private final static String regxpForHtml = "<([^>]*)>"// 过滤所有以<开头以>结尾的标签
private final static String regxpForImgTag = "<\\s*img\\s+([^>]*)\\s*>"// 找出IMG标签
private final static String regxpForImaTagSrcAttrib = "src=\"([^\"]+)\""// 找出IMG标签的SRC属性
/**
*
*/
public HtmlRegexpUtil() {
// TODO Auto-generated constructor stub
}
/**
*
* 基本功能：替换标记以正常显示
* <p>
*
* @param input
* @return String
*/
public String replaceTag(String input) {
if (!hasSpecialChars(input)) {
return input
}
StringBuffer filtered = new StringBuffer(input.length())
char c
for (int i = 0i <= input.length() - 1i++) {
c = input.charAt(i)
switch (c) {
case '<':
filtered.append("<")
break
case '>':
filtered.append(">")
break
case '"':
filtered.append(""")
break
case '&':
filtered.append("&")
break
default:
filtered.append(c)
}
}
return (filtered.toString())
}
/**
*
* 基本功能：判断标记是否存在
* <p>
*
* @param input
* @return boolean
*/
public boolean hasSpecialChars(String input) {
boolean flag = false
if ((input != null) &&(input.length() >0)) {
char c
for (int i = 0i <= input.length() - 1i++) {
c = input.charAt(i)
switch (c) {
case '>':
flag = true
break
case '<':
flag = true
break
case '"':
flag = true
break
case '&':
flag = true
break
}
}
}
return flag
}
/**
*
* 基本功能：过滤所有以"<"开头以">"结尾的标签
* <p>
*
* @param str
* @return String
*/
public static String filterHtml(String str) {
Pattern pattern = Pattern.compile(regxpForHtml)
Matcher matcher = pattern.matcher(str)
StringBuffer sb = new StringBuffer()
boolean result1 = matcher.find()
while (result1) {
matcher.appendReplacement(sb, "")
result1 = matcher.find()
}
matcher.appendTail(sb)
return sb.toString()
}
/**
*
* 基本功能：过滤指定标签
* <p>
*
* @param str
* @param tag
*指定标签
* @return String
*/
public static String fiterHtmlTag(String str, String tag) {
String regxp = "<\\s*" + tag + "\\s+([^>]*)\\s*>"
Pattern pattern = Pattern.compile(regxp)
Matcher matcher = pattern.matcher(str)
StringBuffer sb = new StringBuffer()
boolean result1 = matcher.find()
while (result1) {
matcher.appendReplacement(sb, "")
result1 = matcher.find()
}
matcher.appendTail(sb)
return sb.toString()
}
/**
*
* 基本功能：替换指定的标签
* <p>
*
* @param str
* @param beforeTag
*要替换的标签
* @param tagAttrib
*要替换的标签属性值
* @param startTag
*新标签开始标记
* @param endTag
*新标签结束标记
* @return String
* @如：替换img标签的src属性值为[img]属性值[/img]
*/
public static String replaceHtmlTag(String str, String beforeTag,
String tagAttrib, String startTag, String endTag) {
String regxpForTag = "<\\s*" + beforeTag + "\\s+([^>]*)\\s*>"
String regxpForTagAttrib = tagAttrib + "=\"([^\"]+)\""
Pattern patternForTag = Pattern.compile(regxpForTag)
Pattern patternForAttrib = Pattern.compile(regxpForTagAttrib)
Matcher matcherForTag = patternForTag.matcher(str)
StringBuffer sb = new StringBuffer()
boolean result = matcherForTag.find()
while (result) {
StringBuffer sbreplace = new StringBuffer()
Matcher matcherForAttrib = patternForAttrib.matcher(matcherForTag
.group(1))
if (matcherForAttrib.find()) {
matcherForAttrib.appendReplacement(sbreplace, startTag
+ matcherForAttrib.group(1) + endTag)
}
matcherForTag.appendReplacement(sb, sbreplace.toString())
result = matcherForTag.find()
}
matcherForTag.appendTail(sb)
return sb.toString()
}
}
HTMLPurifier使用了白名单过滤机制，只有被设置允许的才会通过检验。基本过滤事例
a、过滤掉文本中的所有html标签
/**
* 过滤掉所有html标签很简单，原因则在白名单机制完成
*/
$config->set('HTML.Allowed', '')
b、保留超链接标签a及其href链接地址属性，并自动添加target属性值为’_blank’
$config->set('HTML.Allowed', 'a[href]')
$config->set('HTML.TargetBlank', true)
c、自动完成段落代码并清除掉无用的空标签
// 让文本自动添加段落标签，前提是必须允许P标签的使用
$config->set('HTML.Allowed', 'p')
$config->set('AutoFormat.AutoParagraph', true)
// 清除空标签
$config->set('AutoFormat.RemoveEmpty', true)
