Java-Regex-识别并转换成HTML可点击的超链接

public static String convertToHref(String Str){       if (Str==null||Str.equals("")) return Str;      Matcher matcher = null;       Pattern pattern = null;       String str2 = "";       pattern = Pattern.compile("(http://[A-Za-z0-9\\./=\\?%\\-&_~`@':+!]+)|(www\\.[A-Za-z0-9\\./=\\?%\\-&_~`@':+!]+)",Pattern.CASE_INSENSITIVE);       matcher = pattern.matcher(Str);       StringBuffer stringbuffer = new StringBuffer();       for(; matcher.find(); matcher.appendReplacement(stringbuffer, str2)){if(matcher.group(2)!=null)str2 = "<a href=\"http://" + matcher.group(2) + "\" target=\"_blank\"><font color=\"#3333FF\">"+matcher.group(2)+"</font></a>";             else                str2 = "<a href=\"" + matcher.group(1) + "\" target=\"_blank\"><font color=\"#3333FF\">"+matcher.group(1)+"</font></a>";      }      matcher.appendTail(stringbuffer);      return stringbuffer.toString();  }