应用场景：

支付完成后，微信会把相关支付结果和用户信息发送给商户，商户需要接收处理，并返回应答。

对后台通知交互时，如果微信收到商户的应答不是成功或超时，微信认为通知失败，微信会通过一定的策略定期重新发起通知，尽可能提高通知的成功率，但微信不保证通知最终能成功。 （通知频率为15/15/30/180/1800/1800/1800/1800/3600，单位：秒）

注意：同样的通知可能会多次发送给商户系统。商户系统必须能够正确处理重复的通知。

推荐的做法是，当收到通知进行处理时，首先检查对应业务数据的状态，判断该通知是否已经处理过，如果没有处理过再进行处理，如果处理过直接返回结果成功。在对业务数据进行状态检查和处理之前，要采用数据锁进行并发控制，以避免函数重入造成的数据混乱。

特别提醒：商户系统对于支付结果通知的内容一定要做签名验证，防止数据泄漏导致出现“假通知”，造成资金损失。

//支付结果通知接口

@RequestMapping(“/qlydweixinotify.do”)

public void weixinotify(HttpServletRequest request,

HttpServletResponse response) {

PrintWriter out = null;

StringBuffer xmlStr = new StringBuffer();

try {

BufferedReader reader = request.getReader();

String line = null;

while ((line = reader.readLine()) != null) {

xmlStr.append(line);

}

Logger.getLogger(getClass()).debug(“支付回调通知：”+xmlStr.toString());

//检查xml是否有效

boolean flag=Signature.checkIsSignValidFromResponseString(xmlStr.toString());

WeixinNotifyResult result=null;

if(flag){

NotifyResData wxData=(NotifyResData) Util.getObjectFromXML(xmlStr.toString(),NotifyResData.class);

if(wxData !=null){

if(“SUCCESS”.equals(wxData.getReturn_code())){

OrderPayInfo orderPayInfo = new OrderPayInfo();

orderPayInfo.setOrderNum(wxData.getOut_trade_no());

orderPayInfo.setPayNum(wxData.getTransaction_id());

orderPayInfo.setPayPrice((double)wxData.getTotal_fee()/100+”“);

orderPayInfo.setPaySource(wxData.getOpenid());

orderPayInfo.setPayTime(wxData.getTime_end());

orderPayInfo.setPayType(“2”);//1支付宝，2微信支付

OrderMessage returnMessage = orderProductServer

.completeProductOrder(orderPayInfo);

if (OrderStatus.FAIL.equals(returnMessage

.getOrderStatus())) {

Logger.getLogger(getClass()).error(“远程接口完成订单失败”);

result=new WeixinNotifyResult(“FAIL”);

result.setReturn_msg(“远程接口完成订单失败”);

} else {

result=new WeixinNotifyResult(“SUCCESS”);

result.setReturn_msg(“成功”);

}

}else{

result=new WeixinNotifyResult(“FAIL”);

result.setReturn_msg(“失败”);

}

}else{

result=new WeixinNotifyResult(“FAIL”);

result.setReturn_msg(“解析参数格式失败”);

}

}else{

result=new WeixinNotifyResult(“FAIL”);

result.setReturn_msg(“签名失败”);

}

response.getWriter().write(result.toString());

} catch (Exception e) {

Logger.getLogger(getClass()).error(“qlydweixinotify.do”, e);

ResponeDeal.getInstance().sendResponseStr(response, “404”, “连接超时”);

} finally {

if (out != null) {

out.close();

}

}

}

模拟http请求工具类：

HttpsRequestUtil.java

package com.qlwb.weixin.util;

import java.io.IOException;

import org.apache.commons.httpclient.HttpClient;

import org.apache.commons.httpclient.HttpException;

import org.apache.commons.httpclient.methods.PostMethod;

import org.apache.commons.httpclient.methods.RequestEntity;

import org.apache.commons.httpclient.methods.StringRequestEntity;

import org.apache.log4j.Logger;

import com.qlwb.weixin.common.Configure;

import com.qlwb.weixin.common.Util;

import com.qlwb.weixin.protocol.pay_protocol.WxPayReqData;

import com.qlwb.weixin.protocol.payquery_protocol.PayQueryReqData;

public class HttpsRequestUtil {

/**

 *

 * @方法名称:sendWxPayRequest

 * @内容摘要: ＜发送统一下单请求＞

 * @param body

 * @param outTradeNo

 * @param totalFee

 * @param spBillCreateIP

 * @return

 * String

 * @exception

 * @author:鹿伟伟

 * @创建日期:2016年2月19日-下午2:24:05

 */

public String sendWxPayRequest(String body,String detail,String outTradeNo,int totalFee,String spBillCreateIP

        )

{

    // 构造HTTP请求

    HttpClient httpclient = new HttpClient();

    PostMethod postMethod = new PostMethod(Configure.PAY_API);

    WxPayReqData wxdata = new WxPayReqData(body,detail,outTradeNo,totalFee,spBillCreateIP);

    String requestStr="";

    requestStr=Util.ConvertObj2Xml(wxdata);

    // 发送请求

    String strResponse = null;

    try {

        RequestEntity entity = new StringRequestEntity(

                requestStr.toString(), "text/xml", "UTF-8");

        postMethod.setRequestEntity(entity);

        httpclient.executeMethod(postMethod);

        strResponse = new String(postMethod.getResponseBody(), "utf-8");

        Logger.getLogger(getClass()).debug(strResponse);

    } catch (HttpException e) {

        Logger.getLogger(getClass()).error("sendWxPayRequest", e);

    } catch (IOException e) {

        Logger.getLogger(getClass()).error("sendWxPayRequest", e);

    } finally {

        postMethod.releaseConnection();

    }

    return strResponse;

}

/**

 *

 * @方法名称:orderQueryRequest

 * @内容摘要: ＜查询订单信息＞

 * @param transaction_id 微信的订单号，优先使用

 * @return

 * String

 * @exception

 * @author:鹿伟伟

 * @创建日期:2016年2月19日-下午2:44:11

 */

public String orderQueryRequest(String transactionID, String outTradeNo

        )

{

    // 构造HTTP请求

    HttpClient httpclient = new HttpClient();

    PostMethod postMethod = new PostMethod(Configure.PAY_QUERY_API);

    PayQueryReqData wxdata = new PayQueryReqData(transactionID,outTradeNo);

    String requestStr="";

    requestStr=Util.ConvertObj2Xml(wxdata);

    // 发送请求

    String strResponse = null;

    try {

        RequestEntity entity = new StringRequestEntity(

                requestStr.toString(), "text/xml", "UTF-8");

        postMethod.setRequestEntity(entity);

        httpclient.executeMethod(postMethod);

        strResponse = new String(postMethod.getResponseBody(), "utf-8");

    } catch (HttpException e) {

        Logger.getLogger(getClass()).error("orderQueryRequest", e);

    } catch (IOException e) {

        Logger.getLogger(getClass()).error("orderQueryRequest", e);

    } finally {

        postMethod.releaseConnection();

    }

    return strResponse;

}

}