java 微信支付签名生成方法

public static String getSign(Map<String,Object> map){        ArrayList<String> list = new ArrayList<String>();        for(Map.Entry<String,Object> entry:map.entrySet()){            if(entry.getValue()!=""){                list.add(entry.getKey() + "=" + entry.getValue() + "&");            }        }        int size = list.size();        String [] arrayToSort = list.toArray(new String[size]);        Arrays.sort(arrayToSort, String.CASE_INSENSITIVE_ORDER);        StringBuilder sb = new StringBuilder();        for(int i = 0; i < size; i ++) {            sb.append(arrayToSort[i]);        }        String result = sb.toString();        result += "key=" + Configure.getKey();        //Util.log("Sign Before MD5:" + result);        result = MD5.MD5Encode(result).toUpperCase();        //Util.log("Sign Result:" + result);        return result;    }