支付签名 MD5Util 排序工具类

package com.skynet.wechat.wxPay.common;

import java.security.MessageDigest;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;

public class MD5Util {

   private static String charset = "UTF-8";

   /**
    * 创建md5摘要,规则是:按参数名称a-z排序,遇到空值的参数不参加签名。
    */
   @SuppressWarnings("rawtypes")
   public static String createSign(SortedMap<String, String> packageParams,String token) {
      StringBuffer sb = new StringBuffer();
      Set es = packageParams.entrySet();
      Iterator it = es.iterator();
      while (it.hasNext()) {
         Map.Entry entry = (Map.Entry) it.next();
         String k = (String) entry.getKey();
         String v = (String) entry.getValue();
         if (null != v && !"".equals(v) && !"sign".equals(k)
               && !"key".equals(k)) {
            sb.append(k + "=" + v + "&");
         }
      }
      sb.append("key=" + token);
      System.out.println("md5 sb:" + sb);
      String sign = MD5Util.MD5Encode(sb.toString(), charset)
            .toUpperCase();
      System.out.println("签名:" + sign);
      return sign;

   }
   private static String byteArrayToHexString(byte b[]) {
      StringBuffer resultSb = new StringBuffer();
      for (int i = 0; i < b.length; i++)
         resultSb.append(byteToHexString(b[i]));

      return resultSb.toString();
   }

   private static String byteToHexString(byte b) {
      int n = b;
      if (n < 0)
         n += 256;
      int d1 = n / 16;
      int d2 = n % 16;
      return hexDigits[d1] + hexDigits[d2];
   }

   public static String MD5Encode(String origin, String charsetname) {
      String resultString = null;
      try {
         resultString = new String(origin);
         MessageDigest md = MessageDigest.getInstance("MD5");
         if (charsetname == null || "".equals(charsetname))
            resultString = byteArrayToHexString(md.digest(resultString
                  .getBytes()));
         else
            resultString = byteArrayToHexString(md.digest(resultString
                  .getBytes(charsetname)));
      } catch (Exception exception) {
      }
      return resultString;
   }

   private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5",
         "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

   public static void main(String[] args) {

      SortedMap<String, String> packageParams = new TreeMap<String, String>();
      packageParams.put("token", "518e3f22f34d44868717f26d2c1150da");
      packageParams.put("hosId", "419b2c79e2194bd7aa75a584e3e4b2a7");
      packageParams.put("cardID", "8000001852953706");
      packageParams.put("money", "0.10");
      packageParams.put("modeType", "1");
      packageParams.put("serialNumber", "101383989");
      packageParams.put("IDentityCard", "610102197704090934");
      packageParams.put("patientName", "杜涛");
      packageParams.put("telephone", "18740461619");

      String sign = MD5Util.createSign(packageParams, "518e3f22f34d44868717f26d2c1150da");

      System.out.println(sign);

   }
}