setSessionAttr("openid", (WxPayUtil.getOpenIdByCode(code)).get("openid"));

//統(tǒng)一下單，返回xml，用return_code判斷統(tǒng)一下單結(jié)果,獲取prepay_id等預(yù)支付成功信息
String prePayInfoXml = WxPayUtil.unifiedOrder("WxPay", userOrder.getStr("orderNo"), (entity.getBigDecimal("orderMoney").multiply(new BigDecimal(100))).intValue(), WxPayUtil.getIpAddr(getRequest()), getSessionAttr("openid").toString());
//生成包含prepay_id的map，map傳入前端
map = WxPayUtil.getPayMap(prePayInfoXml);
//將訂單號(hào)放入map，用以支付后處理
map.put("orderNo",userOrder.getStr("orderNo"));

<script type="text/javascript">
function payPublic(){
  Common.AjaxSubmitBind("saveForm",function(){
    saveIndex=Common.Loading("正在付款中");
  },function(data){
    prepay_id = data.prepay_id;
    paySign = data.paySign;
    appId = data.appId;
    timeStamp = data.timeStamp;
    nonceStr = data.nonceStr;
    packageStr = data.packageStr;
    signType = data.signType;
    orderNo = data.orderNo;
    callpay();
  },function(errMsg,errCode){
    Common.Alert(errMsg);
  });
}
var prepay_id;
var paySign;
var appId;
var timeStamp;
var nonceStr;
var packageStr;
var signType;
var orderNo;

function onBridgeReady(){
  WeixinJSBridge.invoke(
    'getBrandWCPayRequest', {
      "appId"   : appId,   //公眾號(hào)名稱，由商戶傳入
      "timeStamp" : timeStamp, //時(shí)間戳，自1970年以來(lái)的秒數(shù)
      "nonceStr" : nonceStr , //隨機(jī)串
      "package"  : packageStr,
      "signType" : signType, //微信簽名方式：
      "paySign"  : paySign  //微信簽名
    },
    function(res){
      if(res.err_msg == "get_brand_wcpay_request:ok" ) {
        alert("交易成功");
        window.location.href="${base}/test/paySuccess" rel="external nofollow" ;
      }
      if (res.err_msg == "get_brand_wcpay_request:cancel") { 
        alert("交易取消"); 
        window.location.href="${base}/test/cancel" rel="external nofollow" ;
      } 
      if (res.err_msg == "get_brand_wcpay_request:fail") { 
        alert("支付失敗"); 
        window.location.href="${base}/test/fail" rel="external nofollow" ;
      } 
    }
  );
}
function callpay(){
  if (typeof WeixinJSBridge == "undefined"){
    if( document.addEventListener ){
      document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);
    }else if (document.attachEvent){
      document.attachEvent('WeixinJSBridgeReady', onBridgeReady);
      document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);
    }
  }else{
    onBridgeReady();
  }
}
</script>

public void notify(){
  System.out.print("微信支付回調(diào)獲取數(shù)據(jù)開(kāi)始"); 
  HttpServletRequest request = getRequest();
  String resXml = WxPayUtil.getNotifyResult(request);
  //向微信輸出處理結(jié)果，如果成功（SUCCESS），微信就不會(huì)繼續(xù)調(diào)用了，否則微信會(huì)連續(xù)調(diào)用8次
  renderText(resXml, "text/xml");
}

public class WxPayUtil {
  private static Logger logger = Logger.getLogger(WxPayUtil.class); 
  /**
   * 根據(jù)code獲取openid
   * @param code
   * @return
   * @throws IOException
   */
   public static Map<String,Object> getOpenIdByCode(String code) throws IOException {
    //請(qǐng)求該鏈接獲取access_token
    HttpPost httppost = new HttpPost("https://api.weixin.qq.com/sns/oauth2/access_token");
    //組裝請(qǐng)求參數(shù)
    String reqEntityStr = "appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code";
    reqEntityStr = reqEntityStr.replace("APPID", WxPayConstants.APPID);
    reqEntityStr = reqEntityStr.replace("SECRET", WxPayConstants.APP_SECRET);
    reqEntityStr = reqEntityStr.replace("CODE", code);
    StringEntity reqEntity = new StringEntity(reqEntityStr);
    //設(shè)置參數(shù)
    httppost.setEntity(reqEntity);
    //設(shè)置瀏覽器
    CloseableHttpClient httpclient = HttpClients.createDefault();
    //發(fā)起請(qǐng)求
    CloseableHttpResponse response = httpclient.execute(httppost);
    //獲得請(qǐng)求內(nèi)容
    String strResult = EntityUtils.toString(response.getEntity(), Charset.forName("utf-8"));
    //獲取openid
    JSONObject jsonObject = new JSONObject(strResult);
    Map<String,Object> map = new HashMap<String,Object>();
    map.put("openid",jsonObject.get("openid"));
    map.put("access_token",jsonObject.get("access_token"));
    map.put("refresh_token",jsonObject.get("refresh_token"));
    return map;
  }
  /**
   * 統(tǒng)一下單
   * @param body
   * @param out_trade_no
   * @param total_fee
   * @param IP
   * @param notify_url
   * @param openid
   * @return
   * @throws IOException
   */
  public static String unifiedOrder(String body,String out_trade_no,Integer total_fee,String IP,String openid)throws IOException {
    //設(shè)置訪問(wèn)路徑
    HttpPost httppost = new HttpPost("https://api.mch.weixin.qq.com/pay/unifiedorder");

    String nonce_str = getNonceStr().toUpperCase();//隨機(jī)
    //組裝請(qǐng)求參數(shù),按照ASCII排序
    String sign = "appid=" + WxPayConstants.APPID +
            "&body=" + body +
            "&mch_id=" + WxPayConstants.MCH_ID +
            "&nonce_str=" + nonce_str +
            "&notify_url=" + WxPayConstants.NOTIFY_URL +
            "&openid=" + openid +
            "&out_trade_no=" + out_trade_no +
            "&spbill_create_ip=" + IP +
            "&total_fee=" + total_fee.toString() +
            "&trade_type=" + WxPayConstants.TRADE_TYPE_JS + 
            "&key=" + WxPayConstants.KEY;//這個(gè)字段是用于之后MD5加密的，字段要按照ascii碼順序排序
    sign = ToolMD5.MD5Encode(sign,"").toUpperCase();

    //組裝包含openid用于請(qǐng)求統(tǒng)一下單返回結(jié)果的XML
    StringBuilder sb = new StringBuilder("");
    sb.append("<xml>");
    setXmlKV(sb,"appid",WxPayConstants.APPID);
    setXmlKV(sb,"body",body);
    setXmlKV(sb,"mch_id",WxPayConstants.MCH_ID);
    setXmlKV(sb,"nonce_str",nonce_str);
    setXmlKV(sb,"notify_url",WxPayConstants.NOTIFY_URL);
    setXmlKV(sb,"openid",openid);
    setXmlKV(sb,"out_trade_no",out_trade_no);
    setXmlKV(sb,"spbill_create_ip",IP);
    setXmlKV(sb,"total_fee",total_fee.toString());
    setXmlKV(sb,"trade_type",WxPayConstants.TRADE_TYPE_JS);
    setXmlKV(sb,"sign",sign);
    sb.append("</xml>");
    System.out.println("統(tǒng)一下單請(qǐng)求：" + sb);

    StringEntity reqEntity = new StringEntity(new String (sb.toString().getBytes("UTF-8"),"ISO8859-1"));//這個(gè)處理是為了防止傳中文的時(shí)候出現(xiàn)簽名錯(cuò)誤
    httppost.setEntity(reqEntity);
    CloseableHttpClient httpclient = HttpClients.createDefault();
    CloseableHttpResponse response = httpclient.execute(httppost);
    String strResult = EntityUtils.toString(response.getEntity(), Charset.forName("utf-8"));
    System.out.println("統(tǒng)一下單返回xml：" + strResult);

    return strResult;
  }
  /**
   * 根據(jù)統(tǒng)一下單返回預(yù)支付訂單的id和其他信息生成簽名并拼裝為map（調(diào)用微信支付）
   * @param prePayInfoXml
   * @return
   */
  public static Map<String,Object> getPayMap(String prePayInfoXml){
    Map<String,Object> map = new HashMap<String,Object>();

    String prepay_id = getXmlPara(prePayInfoXml,"prepay_id");//統(tǒng)一下單返回xml中prepay_id
    String timeStamp = String.valueOf((System.currentTimeMillis()/1000));//1970年到現(xiàn)在的秒數(shù)
    String nonceStr = getNonceStr().toUpperCase();//隨機(jī)數(shù)據(jù)字符串
    String packageStr = "prepay_id=" + prepay_id;
    String signType = "MD5";
    String paySign =
        "appId=" + WxPayConstants.APPID +
        "&nonceStr=" + nonceStr +
        "&package=prepay_id=" + prepay_id +
        "&signType=" + signType +
        "&timeStamp=" + timeStamp +
        "&key="+ WxPayConstants.KEY;//注意這里的參數(shù)要根據(jù)ASCII碼 排序
    paySign = ToolMD5.MD5Encode(paySign,"").toUpperCase();//將數(shù)據(jù)MD5加密

    map.put("appId",WxPayConstants.APPID);
    map.put("timeStamp",timeStamp);
    map.put("nonceStr",nonceStr);
    map.put("packageStr",packageStr);
    map.put("signType",signType);
    map.put("paySign",paySign);
    map.put("prepay_id",prepay_id);
    return map;
  }
  /**
   * 修改訂單狀態(tài)，獲取微信回調(diào)結(jié)果
   * @param request
   * @return
   */
  public static String getNotifyResult(HttpServletRequest request){
    String inputLine; 
    String notifyXml = "";
    String resXml = "";
    try { 
      while ((inputLine = request.getReader().readLine()) != null){ 
        notifyXml += inputLine; 
      } 
      request.getReader().close(); 
    } catch (Exception e) { 
      logger.debug("xml獲取失?。? + e);
      e.printStackTrace();
    }
    System.out.println("接收到的xml：" + notifyXml);
    logger.debug("收到微信異步回調(diào)："); 
    logger.debug(notifyXml); 
    if(ToolString.isEmpty(notifyXml)){ 
      logger.debug("xml為空："); 
    }

    String appid = getXmlPara(notifyXml,"appid");; 
    String bank_type = getXmlPara(notifyXml,"bank_type"); 
    String cash_fee = getXmlPara(notifyXml,"cash_fee");
    String fee_type = getXmlPara(notifyXml,"fee_type"); 
    String is_subscribe = getXmlPara(notifyXml,"is_subscribe"); 
    String mch_id = getXmlPara(notifyXml,"mch_id"); 
    String nonce_str = getXmlPara(notifyXml,"nonce_str"); 
    String openid = getXmlPara(notifyXml,"openid"); 
    String out_trade_no = getXmlPara(notifyXml,"out_trade_no");
    String result_code = getXmlPara(notifyXml,"result_code");
    String return_code = getXmlPara(notifyXml,"return_code");
    String sign = getXmlPara(notifyXml,"sign");
    String time_end = getXmlPara(notifyXml,"time_end");
    String total_fee = getXmlPara(notifyXml,"total_fee");
    String trade_type = getXmlPara(notifyXml,"trade_type");
    String transaction_id = getXmlPara(notifyXml,"transaction_id");

    //根據(jù)返回xml計(jì)算本地簽名
    String localSign =
        "appid=" + appid +
        "&bank_type=" + bank_type +
        "&cash_fee=" + cash_fee +
        "&fee_type=" + fee_type +
        "&is_subscribe=" + is_subscribe +
        "&mch_id=" + mch_id +
        "&nonce_str=" + nonce_str +
        "&openid=" + openid +
        "&out_trade_no=" + out_trade_no +
        "&result_code=" + result_code +
        "&return_code=" + return_code +
        "&time_end=" + time_end +
        "&total_fee=" + total_fee +
        "&trade_type=" + trade_type +
        "&transaction_id=" + transaction_id +
        "&key=" + WxPayConstants.KEY;//注意這里的參數(shù)要根據(jù)ASCII碼 排序
    localSign = ToolMD5.MD5Encode(localSign,"").toUpperCase();//將數(shù)據(jù)MD5加密

    System.out.println("本地簽名是：" + localSign);
    logger.debug("本地簽名是：" + localSign); 
    logger.debug("微信支付簽名是：" + sign);

    //本地計(jì)算簽名與微信返回簽名不同||返回結(jié)果為不成功
    if(!sign.equals(localSign) || !"SUCCESS".equals(result_code) || !"SUCCESS".equals(return_code)){
      System.out.println("驗(yàn)證簽名失敗或返回錯(cuò)誤結(jié)果碼"); 
      logger.error("驗(yàn)證簽名失敗或返回錯(cuò)誤結(jié)果碼");
      resXml = "<xml>" + "<return_code><![CDATA[FAIL]]></return_code>" + "<return_msg><![CDATA[FAIL]]></return_msg>" + "</xml> ";
    }else{
       System.out.println("支付成功");
       logger.debug("公眾號(hào)支付成功，out_trade_no(訂單號(hào))為：" + out_trade_no);
       resXml = "<xml>" + "<return_code><![CDATA[SUCCESS]]></return_code>" + "<return_msg><![CDATA[OK]]></return_msg>" + "</xml> ";
    }
    return resXml;
  }
  /**
   * 獲取32位隨機(jī)字符串
   * @return
   */
  public static String getNonceStr(){
    String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    StringBuilder sb = new StringBuilder();
    Random rd = new Random();
    for(int i = 0 ; i < 32 ; i ++ ){
      sb.append(str.charAt(rd.nextInt(str.length())));
    }
    return sb.toString();
  }
  /**
   * 插入XML標(biāo)簽
   * @param sb
   * @param Key
   * @param value
   * @return
   */
  public static StringBuilder setXmlKV(StringBuilder sb,String Key,String value){
    sb.append("<");
    sb.append(Key);
    sb.append(">");

    sb.append(value);

    sb.append("</");
    sb.append(Key);
    sb.append(">");

    return sb;
  }

  /**
   * 解析XML 獲得名稱為para的參數(shù)值
   * @param xml
   * @param para
   * @return
   */
  public static String getXmlPara(String xml,String para){
    int start = xml.indexOf("<"+para+">");
    int end = xml.indexOf("</"+para+">");

    if(start < 0 && end < 0){
      return null;
    }
    return xml.substring(start + ("<"+para+">").length(),end).replace("<![CDATA[","").replace("]]>","");
  }

  /**
   * 獲取ip地址
   * @param request
   * @return
   */
  public static String getIpAddr(HttpServletRequest request) { 
    InetAddress addr = null; 
    try { 
      addr = InetAddress.getLocalHost(); 
    } catch (UnknownHostException e) { 
      return request.getRemoteAddr(); 
    } 
    byte[] ipAddr = addr.getAddress(); 
    String ipAddrStr = ""; 
    for (int i = 0; i < ipAddr.length; i++) { 
      if (i > 0) { 
        ipAddrStr += "."; 
      } 
      ipAddrStr += ipAddr[i] & 0xFF; 
    } 
    return ipAddrStr; 
  }
}

public class WxPayConstants {
  //第三方用戶唯一ID
  public static String APPID = "";
  //第三方用戶唯一憑證密碼
  public static String APP_SECRET = "";
  //商戶ID
  public static String MCH_ID = "";
  //微信商戶平臺(tái)-賬戶設(shè)置-安全設(shè)置-api安全,配置32位key
  public static String KEY = "";
  //交易類型
  public static String TRADE_TYPE_JS = "JSAPI";
  //微信支付回調(diào)url
  public static String NOTIFY_URL = "";
}