通用解析搜索关键词类

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SeoURLKeyword {
public static String keywordReg = "^(?:http|https)://.+(?:\\.baidu\\.com.*[\\&|\\?](?:wd|word)=" +
"|\\.soso\\.com.*[\\&|\\?]w=" +
"|\\.sogou\\.com.*[\\&|\\?]query=" +
"|\\.bing\\.com.*[\\&|\\?]q=" +
"|\\.youdao\\.com.*[\\&|\\?]q=" +
"|\\.google\\.com.*[\\&|\\?]q=" +
"|\\.360\\.cn.*[\\&|\\?][kw|q]=" +
"|\\.360sou\\.com.*[\\&|\\?](?:kw|q)=" +
"|\\.so\\.com.*[\\&|\\?](?:kw|q)=)([^&]*)";
public static String  encodeReg = "^(?:[\\x00-\\x7f]|[\\xfc-\\xff][\\x80-\\xbf]{5}|[\\xf8-\\xfb][\\x80-\\xbf]{4}|[\\xf0-\\xf7][\\x80-\\xbf]{3}|[\\xe0-\\xef][\\x80-\\xbf]{2}|[\\xc0-\\xdf][\\x80-\\xbf])+$";
public static String parsePercent(String dataStr) {
        if(dataStr.length() <= 1 ){
                return "%".equals(dataStr)? "%25":dataStr;
        }
        StringBuffer buffer = new StringBuffer();
        String[] arr = new String[]{};
        int sIdx = dataStr.indexOf("%");
        int eIdx = dataStr.lastIndexOf("%");
        if (sIdx == -1){
                return dataStr;
        }else{
                buffer.append(dataStr.substring(0,sIdx));
                arr = dataStr.substring(sIdx+1).split("%");
        }
        for (int i = 0; i < arr.length; i++) {
                if (arr[i].length() < 2) {
                        buffer.append("%25");
                } else {
                        if(Util.isShiLiu(arr[i].substring(0,2))){
                                buffer.append("%");
                        }else{
                                buffer.append("%25");
                        }
                }
                buffer.append(arr[i]);
        }
        if (eIdx == dataStr.length()-1) {
                buffer.append("%25");
        }
        return buffer.toString();
}//end parsePercent
public static String getKeyword(String url, String defaultKw) {
        Pattern keywordPatt = Pattern.compile(keywordReg);
        StringBuffer keyword = new StringBuffer(20);
        Matcher keywordMat = keywordPatt.matcher(url);
        while (keywordMat.find()) {
                keywordMat.appendReplacement(keyword, "$1");
        }            
        if (!keyword.toString().equals("")) {
                String keywordsTmp  = filterPercent25(keyword.toString());
                keywordsTmp = parsePercent(keywordsTmp);
                Pattern encodePatt = Pattern.compile(encodeReg);
                String unescapeString = ParseURLKeyword.unescape(keywordsTmp);
                Matcher encodeMat = encodePatt.matcher(unescapeString);
                String encodeString = "gbk";
                if (encodeMat.matches())
                       encodeString = "utf-8";
                try {
                        return decode(keywordsTmp, encodeString).trim();
                } catch (UnsupportedEncodingException e) {
                        return defaultKw;
                }
       }
       return defaultKw;
}//end getKeyword

public static String decode(String kw, String encode) throws UnsupportedEncodingException{
       if(kw.startsWith("%u")){
              kw =  unescape(kw);
       }
       return URLDecoder.decode(kw, encode);
}//end decode
public static String filterPercent25(String str){
       String strUnicode = str;
       //%25
       int n = 0;
       while (strUnicode.contains("%25")) {
              strUnicode = strUnicode.replace("%25", "%");
              n++;
              if (n == 3)
                     break;
       }
       //+
       strUnicode = strUnicode.replace("+", "");
       return strUnicode.trim();
}// end filterPercent25
public static String unescape(String src) {
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length());
        int lastPos = 0, pos = 0;
        char ch;
        while (lastPos < src.length()) {
                pos = src.indexOf("%", lastPos);
                if (pos == lastPos) {
                        if (src.charAt(pos + 1) == 'u') {
                                ch = (char) Integer.parseInt(src.substring(pos + 2, pos + 6), 16);
                                tmp.append(ch);
                                lastPos = pos + 6;
                        } else {
                                ch = (char) Integer.parseInt(src.substring(pos + 1, pos + 3), 16);
                                tmp.append(ch);
                                lastPos = pos + 3;
                        }
              } else {
                      if (pos == -1) {
                                tmp.append(src.substring(lastPos));
                                lastPos = src.length();
                      } else {
                                tmp.append(src.substring(lastPos, pos));
                                lastPos = pos;
                      }
             }
     }
     return tmp.toString();
}//end  unescape
}