截取在线编辑器的字符串怎么处理

/**
* 按字节长度截取字符串(支持截取带HTML代码样式的字符串)
* @param param 将要截取的字符串参数
* @param length 截取的字节长度
* @param end 字符串末尾补上的字符串
* @return 返回截取后的字符串
*/
public String subStringHTML(String param,int length,String end) {
StringBuffer result = new StringBuffer();
int n = 0;
char temp;
boolean isCode = false; //是不是HTML代码
boolean isHTML = false; //是不是HTML特殊字符,如 
for (int i = 0; i < param.length(); i++) {
temp = param.charAt(i);
if (temp == '<') {
isCode = true;
}
else if (temp == '&') {
isHTML = true;
}
else if (temp == '>' && isCode) {
n = n - 1;
isCode = false;
}
else if (temp == ';' && isHTML) {
isHTML = false;
}

if (!isCode && !isHTML) {
n = n + 1;
//UNICODE码字符占两个字节
if ( (temp + "").getBytes().length > 1) {
n = n + 1;
}
}

result.append(temp);
if (n >= length) {
break;
}
}
result.append(end);
//取出截取字符串中的HTML标记
String temp_result = result.toString().replaceAll("(>)[^<>]*(<?)", "$1$2");
//去掉不需要结素标记的HTML标记
temp_result = temp_result.replaceAll("</?(AREA|BASE|BASEFONT|BODY|BR|COL|COLGROUP|DD|DT|FRAME|HEAD|HR|HTML|IMG|INPUT|ISINDEX|LI|LINK|META|OPTION|P|PARAM|TBODY|TD|TFOOT|TH|THEAD|TR|area|base|basefont|body|br|col|colgroup|dd|dt|frame|head|hr|html|img|input|isindex|li|link|meta|option|p|param|tbody|td|tfoot|th|thead|tr)[^<>]*/?>",
"");
//去掉成对的HTML标记
temp_result=temp_result.replaceAll("<([a-zA-Z]+)[^<>]*>(.*?)</\\1>","$2");
//用正则表达式取出标记
Pattern p = Pattern.compile("<([a-zA-Z]+)[^<>]*>");
Matcher m = p.matcher(temp_result);

List endHTML = new ArrayList();

while (m.find()) {
endHTML.add(m.group(1));
}
//补全不成对的HTML标记
for (int i = endHTML.size() - 1; i >= 0; i--) {
result.append("</");
result.append(endHTML.get(i));
result.append(">");
}

return result.toString();
}