Java截取带html标签的字符串,再把标签补全(保证页

import Java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

/**
* @author

* @version 1.0
*
* 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 class SubStringHTML
{
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();
   }

}