java 后台去除HTML标签

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

public class StringUtil {
    
    private final static String  REGXP_FOR_HTML= "</?[^>]+>"; // 去除P标签        

    private final static String REGXP_FOR_IMG_TAG="<img.*src\\s*=\\s*(.*?)[^>]*?>"; // 找出IMG标签

    private final static String  REGXP_FOR_IMG_TAG_SRC_ATTRIB="src\\s*=\\s*\"?(.*?)(\"|>|\\s+)"; // 找出IMG标签的SRC属性
    
   private final static String   REGXP_FOR_ldquo="\\&[a-zA-Z]{1,10};";  //去除&ldquo;标签

//---------------------------------------------------------------------
    public  static List<String> getImgStr(String htmlStr){   
          String img="";   
        Pattern p_image;   
        Matcher m_image;   
        List<String> pics = new ArrayList<String>();
        p_image = Pattern.compile
                (REGXP_FOR_IMG_TAG,Pattern.CASE_INSENSITIVE);   
       m_image = p_image.matcher(htmlStr);
       while(m_image.find()){   
            img = img + "," + m_image.group();   
           Matcher m  = Pattern.compile(REGXP_FOR_IMG_TAG_SRC_ATTRIB).matcher(img);
            while(m.find()){
                String a=m.group(1);
                if(a.indexOf("/")!=-1){
                    a=a.substring(a.lastIndexOf("/")+1,a.length());
                }
                pics.add(a);
            }
        }   
           return pics;
     }
    /**
     * 过滤<img>标签
     * @param str
     * @return
     */
    public static String fiterImgTag(String str) {
        Pattern pattern = Pattern.compile(REGXP_FOR_IMG_TAG);
        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
     */
    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();
    }
    /**
     * 过滤所以html标签
     * @param str
     * @return
     * @return
     */
    public static String filterHtml(String str) {
        Pattern pattern = Pattern.compile(REGXP_FOR_HTML);
        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 ldquo(sb.toString());
    }
    
    /**
     * 去除&ldquo;标签
     * @param str
     * @return
     */
    private static String ldquo(String str){
         Pattern pattern = Pattern.compile(REGXP_FOR_ldquo);
          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();
    }
    /**
     * 切割Sting
     * @param str 原字符串
     * @param star 开始位置
     * @param length 需要切割的长度
     * @return
     */
    public static String substring(String str,int star,int length){
        if((star+length)>str.length()){
            str=str.substring(star,str.length());
        }else{
            str=str.substring(star, star+length);
        }
        return str;
    }

}