springboot對(duì)接微信支付的完整流程（附前后端代碼）

更新時(shí)間：2021年08月03日 09:22:25 作者：小小舍

最近在做支付平臺(tái)的項(xiàng)目,承接公司業(yè)務(wù)系統(tǒng)與第三方支付平臺(tái)的對(duì)接任務(wù),主要涉及微信支付、支付寶支付以及理房通支付等第三方平臺(tái),這篇文章主要給大家介紹了關(guān)于springboot對(duì)接微信支付的完整流程,需要的朋友可以參考下

展示圖：

對(duì)接的完整流程如下

首先是配置

gzh.appid=公眾號(hào)appid
wxPay.mchId=商戶號(hào)
wxPay.key=支付密鑰
wxPay.notifyUrl=域名回調(diào)地址

常量：

/**微信支付統(tǒng)一下單接口*/
    public static final String unifiedOrderUrl = "https://api.mch.weixin.qq.com/pay/unifiedorder";
 
 
    public static String SUCCESSxml = "<xml> \r\n" +
            "\r\n" +
            "  <return_code><![CDATA[SUCCESS]]></return_code>\r\n" +
            "   <return_msg><![CDATA[OK]]></return_msg>\r\n" +
            " </xml> \r\n" +
            "";
    public static String ERRORxml =  "<xml> \r\n" +
            "\r\n" +
            "  <return_code><![CDATA[FAIL]]></return_code>\r\n" +
            "   <return_msg><![CDATA[invalid sign]]></return_msg>\r\n" +
            " </xml> \r\n" +
            "";

工具類準(zhǔn)備：

package com.jc.utils.util;
 
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.EntityUtils;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import javax.net.ssl.SSLContext;
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.text.SimpleDateFormat;
import java.util.*;
 
public class CommUtils {
    private static Logger logger = LoggerFactory.getLogger(CommUtils.class);
    // 連接超時(shí)時(shí)間，默認(rèn)10秒
    private static int socketTimeout = 60000;
 
    // 傳輸超時(shí)時(shí)間，默認(rèn)30秒
    private static int connectTimeout= 60000;
    /**
     * Util工具類方法
     * 獲取一定長度的隨機(jī)字符串，范圍0-9，a-z
     * @param length：指定字符串長度
     * @return 一定長度的隨機(jī)字符串
     */
    public static String getRandomStringByLength(int length) {
        String base = "abcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < length; i++) {
            int number = random.nextInt(base.length());
            sb.append(base.charAt(number));
        }
        return sb.toString();
    }
 
    /**
     * 獲取訂單號(hào)
     * @return
     */
    public static String getOrderNo(){
 
        SimpleDateFormat ft = new SimpleDateFormat("yyyyMMddHHmmss");
        String time = ft.format(new Date());
        int mathCode = (int) ((Math.random() * 9 + 1) * 10000);// 5位隨機(jī)數(shù)
        String resultCode = time+mathCode;
        return resultCode;
    }
 
    /**
     * Util工具類方法
     * 獲取真實(shí)的ip地址
     * @param request
     * @return
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            //多次反向代理后會(huì)有多個(gè)ip值，
            int index = ip.indexOf(",");
            if (index != -1) {
                return ip.substring(0, index);
            } else {
                return ip;
            }
        }
        ip = request.getHeader("X-Real-IP");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            return ip;
        }
        return request.getRemoteAddr();
 
    }
 
    /**
     * 簽名字符串
     * @param text 需要簽名的字符串
     * @param key 密鑰
     * @param input_charset 編碼格式
     * @return 簽名結(jié)果
     */
    public static String sign(String text, String key, String input_charset) {
        text = text + "&key=" + key;
        System.out.println(text);
        return DigestUtils.md5Hex(getContentBytes(text, input_charset));
    }
 
    /**
     * 簽名字符串
     * @param text 需要簽名的字符串
     * @param sign 簽名結(jié)果
     * @param key 密鑰
     * @param input_charset 編碼格式
     * @return 簽名結(jié)果
     */
    public static boolean verify(String text, String sign, String key, String input_charset) {
        text = text + key;
        String mysign = DigestUtils.md5Hex(getContentBytes(text, input_charset));
        if (mysign.equals(sign)) {
            return true;
        } else {
            return false;
        }
    }
    /**
     * @param content
     * @param charset
     * @return
     * @throws UnsupportedEncodingException
     */
    public static byte[] getContentBytes(String content, String charset) {
        if (charset == null || "".equals(charset)) {
            return content.getBytes();
        }
        try {
            return content.getBytes(charset);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("MD5簽名過程中出現(xiàn)錯(cuò)誤,指定的編碼集不對(duì),您目前指定的編碼集是:" + charset);
        }
    }
 
    /**
     * 生成6位或10位隨機(jī)數(shù) param codeLength(多少位)
     * @return
     */
    public static String createCode(int codeLength) {
        String code = "";
        for (int i = 0; i < codeLength; i++) {
            code += (int) (Math.random() * 9);
        }
        return code;
    }
 
    @SuppressWarnings("unused")
    private static boolean isValidChar(char ch) {
        if ((ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
            return true;
        if ((ch >= 0x4e00 && ch <= 0x7fff) || (ch >= 0x8000 && ch <= 0x952f))
            return true;// 簡體中文漢字編碼
        return false;
    }
 
    /**
     * 除去數(shù)組中的空值和簽名參數(shù)
     * @param sArray 簽名參數(shù)組
     * @return 去掉空值與簽名參數(shù)后的新簽名參數(shù)組
     */
    public static Map<String, String> paraFilter(Map<String, String> sArray) {
        Map<String, String> result = new HashMap<>();
        if (sArray == null || sArray.size() <= 0) {
            return result;
        }
        for (String key : sArray.keySet()) {
            String value = sArray.get(key);
            if (value == null || value.equals("") || key.equalsIgnoreCase("sign")
                    || key.equalsIgnoreCase("sign_type")) {
                continue;
            }
            result.put(key, value);
        }
        return result;
    }
 
    /**
     * 把數(shù)組所有元素排序，并按照“參數(shù)=參數(shù)值”的模式用“&”字符拼接成字符串
     * @param params 需要排序并參與字符拼接的參數(shù)組
     * @return 拼接后字符串
     */
    public static String createLinkString(Map<String, String> params) {
        List<String> keys = new ArrayList<>(params.keySet());
        Collections.sort(keys);
        String prestr = "";
        for (int i = 0; i < keys.size(); i++) {
            String key = keys.get(i);
            String value = params.get(key);
            if (i == keys.size() - 1) {// 拼接時(shí)，不包括最后一個(gè)&字符
                prestr = prestr + key + "=" + value;
            } else {
                prestr = prestr + key + "=" + value + "&";
            }
        }
        return prestr;
    }
    /**
     *
     * @param requestUrl 請(qǐng)求地址
     * @param requestMethod 請(qǐng)求方法
     * @param outputStr 參數(shù)
     */
    public static String httpRequest(String requestUrl,String requestMethod,String outputStr){
        logger.warn("請(qǐng)求報(bào)文："+outputStr);
        StringBuffer buffer = null;
        try{
            URL url = new URL(requestUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod(requestMethod);
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.connect();
            //往服務(wù)器端寫內(nèi)容
            if(null !=outputStr){
                OutputStream os=conn.getOutputStream();
                os.write(outputStr.getBytes("utf-8"));
                os.close();
            }
            // 讀取服務(wù)器端返回的內(nèi)容
            InputStream is = conn.getInputStream();
            InputStreamReader isr = new InputStreamReader(is, "utf-8");
            BufferedReader br = new BufferedReader(isr);
            buffer = new StringBuffer();
            String line = null;
            while ((line = br.readLine()) != null) {
                buffer.append(line);
            }
            br.close();
        }catch(Exception e){
            e.printStackTrace();
        }
        logger.warn("返回報(bào)文："+buffer.toString());
        return buffer.toString();
    }
 
    /**
     * POST請(qǐng)求
     * @param url           請(qǐng)求url
     * @param xmlParam      請(qǐng)求參數(shù)
     * @param apiclient     證書
     * @param mch_id        商戶號(hào)
     * @return
     * @throws Exception
     */
    public static String post(String url, String xmlParam,String apiclient,String mch_id) throws Exception {
        logger.warn("請(qǐng)求報(bào)文："+xmlParam);
        StringBuilder sb = new StringBuilder();
        try {
            KeyStore keyStore = KeyStore.getInstance("PKCS12");
            FileInputStream instream = new FileInputStream(new File(apiclient));
            try {
                keyStore.load(instream, mch_id.toCharArray());
            } finally {
                instream.close();
            }
            // 證書
            SSLContext sslcontext = SSLContexts.custom()
                    .loadKeyMaterial(keyStore, mch_id.toCharArray()).build();
            // 只允許TLSv1協(xié)議
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                    sslcontext, new String[]{"TLSv1"}, null, SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
            //創(chuàng)建基于證書的httpClient,后面要用到
            CloseableHttpClient client = HttpClients.custom().setSSLSocketFactory(sslsf).build();
            HttpPost httpPost = new HttpPost(url);//退款接口
            StringEntity reqEntity = new StringEntity(xmlParam,"UTF-8");
            // 設(shè)置類型
            reqEntity.setContentType("application/x-www-form-urlencoded");
            httpPost.setEntity(reqEntity);
            CloseableHttpResponse response = client.execute(httpPost);
            try {
                HttpEntity entity = response.getEntity();
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
                    String text = "";
                    while ((text = bufferedReader.readLine()) != null) {
                        sb.append(text);
                    }
                }
                EntityUtils.consume(entity);
 
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
 
        } catch (KeyStoreException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
        logger.warn("返回報(bào)文："+sb.toString());
        return sb.toString();
    }
 
    public static String urlEncodeUTF8(String source){
        String result=source;
        try {
            result=java.net.URLEncoder.encode(source, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return result;
    }
    /**
     * 解析xml,返回第一級(jí)元素鍵值對(duì)。如果第一級(jí)元素有子節(jié)點(diǎn)，則此節(jié)點(diǎn)的值是子節(jié)點(diǎn)的xml數(shù)據(jù)。
     * @param strxml
     * @return
     * @throws org.jdom2.JDOMException
     * @throws IOException
     */
    public static Map doXMLParse(String strxml) throws Exception {
        if(null == strxml || "".equals(strxml)) {
            return null;
        }
 
        Map m = new HashMap();
        InputStream in = String2Inputstream(strxml);
        SAXBuilder builder = new SAXBuilder();
        Document doc = builder.build(in);
        Element root = doc.getRootElement();
        List list = root.getChildren();
        Iterator it = list.iterator();
        while(it.hasNext()) {
            Element e = (Element) it.next();
            String k = e.getName();
            String v = "";
            List children = e.getChildren();
            if(children.isEmpty()) {
                v = e.getTextNormalize();
            } else {
                v = getChildrenText(children);
            }
 
            m.put(k, v);
        }
        in.close();
 
        return m;
    }
 
    /**
     * 獲取子結(jié)點(diǎn)的xml
     * @param children
     * @return String
     */
    public static String getChildrenText(List children) {
        StringBuffer sb = new StringBuffer();
        if(!children.isEmpty()) {
            Iterator it = children.iterator();
            while(it.hasNext()) {
                Element e = (Element) it.next();
                String name = e.getName();
                String value = e.getTextNormalize();
                List list = e.getChildren();
                sb.append("<" + name + ">");
                if(!list.isEmpty()) {
                    sb.append(getChildrenText(list));
                }
                sb.append(value);
                sb.append("</" + name + ">");
            }
        }
 
        return sb.toString();
    }
    public static InputStream String2Inputstream(String str) {
        return new ByteArrayInputStream(str.getBytes());
    }
 
 
 
 
}

controller：

package com.jch.mng.controller;
 
import com.jch.boot.component.CommonInfo;
import com.jch.boot.component.Result;
import com.jch.boot.component.ServiceCommonInfo;
import com.jch.mng.dto.input.gzh.WxPayDto;
import com.jch.mng.service.WxPayService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * Created by xxs on 2021/7/30 10:54
 *
 * @Description 公眾號(hào)微信支付
 * @Version 2.9
 */
@RestController
@RequestMapping("/wxPay")
public class WxPayController {
 
   
 
    @Autowired
    private WxPayService payService;
 
 
    /**
    * @Author: xxs
    * @param dto
     * @param request
    * @Date: 2021/7/30 11:55
    * @Description:  公眾號(hào)微信支付
    * @Version: 2.9
    * @Return: com.jch.boot.component.Result<java.lang.String>
    */
    @PostMapping("/pay")
    public Result<String> pay(@RequestBody WxPayDto dto, HttpServletRequest request) throws Exception {
        ServiceCommonInfo<Object> result = payService.pay(dto,request);
        return CommonInfo.controllerBack(result);
    }
 
 
    /**
    * @Author: xxs
    * @param request
     * @param response
    * @Date: 2021/7/30 11:55
    * @Description:  支付回調(diào)
    * @Version: 2.9
    * @Return: void
    */
    @PostMapping("/notify")
    public void notify(HttpServletRequest request, HttpServletResponse response) throws Exception {
        payService.notify(request,response);
    }
 
}

service接口：

package com.jch.mng.service;
 
import com.jch.boot.component.ServiceCommonInfo;
import com.jch.mng.dto.input.gzh.WxPayDto;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * Created by xxs on 2021/7/30 9:56
 *
 * @Description
 * @Version 2.9
 */
public interface WxPayService {
 
    ServiceCommonInfo<Object> pay(WxPayDto dto, HttpServletRequest request) throws Exception;
 
    void notify(HttpServletRequest request, HttpServletResponse response) throws Exception;
}

接口實(shí)現(xiàn)：

package com.jch.mng.service.impl;
 
import com.alibaba.fastjson.JSON;
import com.jc.utils.util.CommUtils;
import com.jch.boot.component.ServiceCommonInfo;
import com.jch.mng.constant.WeChatConstants;
import com.jch.mng.dto.input.gzh.WxPayDto;
import com.jch.mng.service.WxPayService;
import com.jch.mng.utils.DoubleUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
 
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
 
/**
 * Created by xxs on 2021/7/30 9:56
 *
 * @Description
 * @Version 2.9
 */
@Service
public class WxPayServiceImpl implements WxPayService {
    public  String appId;
 
    public  String mch_id;
 
    public  String notify_url;
 
    public  String key;
 
    @Value("${gzh.appid}")
    public void setAppId(String appId) {
        this.appId = appId;
    }
    @Value("${wxPay.mchId}")
    public void setMch_id(String mch_id) {
        this.mch_id = mch_id;
    }
    @Value("${wxPay.notifyUrl}")
    public void setNotify_url(String notify_url) {
        this.notify_url = notify_url;
    }
    @Value("${wxPay.key}")
    public void setKey(String key) {
        this.key = key;
    }
 
 
    private static Logger logger = LoggerFactory.getLogger(WxPayServiceImpl.class);
 
 
    /**
    * @Author: xxs
    * @param dto
     * @param request
    * @Date: 2021/7/30 11:01
    * @Description:  微信支付
    * @Version: 2.9
    * @Return: com.jch.boot.component.ServiceCommonInfo<java.lang.Object>
    */
    @Override
    public ServiceCommonInfo<Object> pay(WxPayDto dto, HttpServletRequest request) throws Exception {
        logger.info("公眾號(hào)微信支付, 入?yún)?{}", JSON.toJSONString(dto));
        String openid = dto.getOpenid();
        String outTradeNo = dto.getOutTradeNo();
        String body = dto.getBody();
        Double totalFee = dto.getTotalFee();
        String nonce_str = CommUtils.getRandomStringByLength(32);
        String spbill_create_ip = CommUtils.getIpAddr(request);
        Map<String, String> packageParams = new HashMap<>();
        packageParams.put("appid", appId);
        packageParams.put("mch_id",mch_id);
        packageParams.put("nonce_str", nonce_str);
        packageParams.put("body", body);
        packageParams.put("out_trade_no", outTradeNo);
        double t = DoubleUtil.parseDouble(totalFee);//保留兩位小數(shù)
        int aDouble = Integer.parseInt(new java.text.DecimalFormat("0").format(t*100));
        packageParams.put("total_fee", aDouble+"");
        packageParams.put("spbill_create_ip", spbill_create_ip);
        packageParams.put("notify_url", notify_url);
        packageParams.put("trade_type","JSAPI");
        packageParams.put("openid", openid);
 
        packageParams = CommUtils.paraFilter(packageParams);
        String prestr = CommUtils.createLinkString(packageParams);
        String sign = CommUtils.sign(prestr, key, "utf-8").toUpperCase();
        logger.info("統(tǒng)一下單請(qǐng)求簽名：" + sign );
        String xml = "<xml version='1.0' encoding='gbk'>" + "<appid>" + appId + "</appid>"
                + "<body><![CDATA[" + body + "]]></body>"
                + "<mch_id>" + mch_id + "</mch_id>"
                + "<nonce_str>" + nonce_str + "</nonce_str>"
                + "<notify_url>" + notify_url+ "</notify_url>"
                + "<openid>" + openid + "</openid>"
                + "<out_trade_no>" + outTradeNo + "</out_trade_no>"
                + "<spbill_create_ip>" + spbill_create_ip + "</spbill_create_ip>"
                + "<total_fee>" + aDouble+"" + "</total_fee>"
                + "<trade_type>" + "JSAPI" + "</trade_type>"
                + "<sign>" + sign + "</sign>"
                + "</xml>";
 
        String result = CommUtils.httpRequest(WeChatConstants.unifiedOrderUrl, "POST", xml);
        Map map = CommUtils.doXMLParse(result);
        Object return_code =  map.get("return_code");
        logger.info("統(tǒng)一下單返回return_code：" + return_code );
        if(return_code == "SUCCESS"  || return_code.equals(return_code)){
            Map<String,String> resultMap=new HashMap<String, String>();
            String prepay_id = (String) map.get("prepay_id");
            resultMap.put("appId", appId);
            Long timeStamp = System.currentTimeMillis() / 1000;
            resultMap.put("timeStamp", timeStamp + "");
            resultMap.put("nonceStr", nonce_str);
            resultMap.put("package", "prepay_id=" + prepay_id);
            resultMap.put("signType", "MD5");
            logger.info("參與paySign簽名數(shù)據(jù), 入?yún)?{}", JSON.toJSONString(resultMap));
            String linkString = CommUtils.createLinkString(resultMap);
            String paySign = CommUtils.sign(linkString, key, "utf-8").toUpperCase();
            logger.info("獲取到paySign:"+paySign);
            resultMap.put("paySign", paySign);
            return ServiceCommonInfo.success("ok", resultMap);
        }
        return ServiceCommonInfo.serviceFail("支付失敗", null);
    }
 
 
    /**
    * @Author: xxs
    * @param request
     * @param response
    * @Date: 2021/7/31 15:17
    * @Description:  微信支付回調(diào)
    * @Version: 2.9
    * @Return: void
    */
    @Override
    public void notify(HttpServletRequest request, HttpServletResponse response) throws Exception {
        logger.info("進(jìn)入支付回調(diào)啦啦啦啦*-*");
        String resXml = "";
        BufferedReader br = new BufferedReader(new InputStreamReader((ServletInputStream) request.getInputStream()));
        String line = null;
        StringBuilder sb = new StringBuilder();
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }
        br.close();
        String notityXml = sb.toString();
        logger.info("支付回調(diào)返回?cái)?shù)據(jù)："+notityXml);
        Map map = CommUtils.doXMLParse(notityXml);
        Object returnCode = map.get("return_code");
        Object result_code = map.get("result_code");
        if ("SUCCESS".equals(returnCode) && "SUCCESS".equals(result_code)) {
            Map<String, String> validParams = CommUtils.paraFilter(map);  //回調(diào)驗(yàn)簽時(shí)需要去除sign和空值參數(shù)
            String validStr = CommUtils.createLinkString(validParams);//把數(shù)組所有元素，按照“參數(shù)=參數(shù)值”的模式用“&”字符拼接成字符串
            String sign = CommUtils.sign(validStr, key , "utf-8").toUpperCase();//拼裝生成服務(wù)器端驗(yàn)證的簽名
            logger.info("支付回調(diào)生成簽名："+sign);
            String transaction_id = (String) map.get("transaction_id");
            String order_no = (String) map.get("out_trade_no");
            String time_end = (String) map.get("time_end");
            String total_fee = (String) map.get("total_fee");
            //簽名驗(yàn)證,并校驗(yàn)返回的訂單金額是否與商戶側(cè)的訂單金額一致
            if (sign.equals(map.get("sign"))) {
                logger.info("支付回調(diào)驗(yàn)簽通過");
                //通知微信服務(wù)器已經(jīng)支付成功
                resXml = WeChatConstants.SUCCESSxml;
            } else {
                logger.info("微信支付回調(diào)失敗!簽名不一致");
            }
        }else{
            resXml = WeChatConstants.ERRORxml;
        }
        System.out.println(resXml);
        logger.info("微信支付回調(diào)返回?cái)?shù)據(jù)："+resXml);
        logger.info("微信支付回調(diào)數(shù)據(jù)結(jié)束");
        BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
        out.write(resXml.getBytes());
        out.flush();
        out.close();
    }
}

前端頁面：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0;" name="viewport" />
</head>
<body>
    body: <input type="text" class="inp-body"><br>
    outTradeNo: <input type="text" class="inp-outTradeNo"><br>
    totalFee: <input type="text" class="inp-totalFee"><br>
    openid: <input type="text" class="inp-openid"><br>
    <button onclick="handleWxPay()">支付</button>
</body>
</html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
    function handleWxPay(){
        let obj = {
            "body":$(".inp-body").val(),
            "outTradeNo":$(".inp-outTradeNo").val(),
            "totalFee":$(".inp-totalFee").val(),
            "openid":$(".inp-openid").val(),
        }
        $.ajax({
            type: "POST",
            url: "微信支付接口地址",
            data:JSON.stringify(obj),
            beforeSend: function(request) {
                request.setRequestHeader("Content-Type","application/json");
            },
            success: result=> {
                let obj = JSON.parse(result.data)
                onBridgeReady(obj)
            }
        });
    }
 
 
    function onBridgeReady(obj){
        WeixinJSBridge.invoke(
            'getBrandWCPayRequest', obj,
            function(res){
                alert(JSON.stringify(res))
                if(res.err_msg == "get_brand_wcpay_request:ok" ){
                    // 使用以上方式判斷前端返回,微信團(tuán)隊(duì)鄭重提示：
                    //res.err_msg將在用戶支付成功后返回ok，但并不保證它絕對(duì)可靠。
                }
            });
    }
</script>

訪問前端頁面記得加依賴：

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

訪問頁面需要寫控制類：

package com.jch.mng.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
 
import javax.servlet.http.HttpServletResponse;
 
/**
 * Created by xxs on 2021/7/31 12:29
 *
 * @Description
 * @Version 2.9
 */
@Controller
public class TestPageController {
 
 
    @RequestMapping("/wxPayTest")
    public String test(HttpServletResponse response)  {
        return "wxPay";
    }
}

運(yùn)行項(xiàng)目訪問。

部署項(xiàng)目到服務(wù)器，用手機(jī)訪問即可拉起支付。

附：名詞解釋

商戶號(hào)：微信支付分配的商戶號(hào)。支付審核通過后，申請(qǐng)人郵箱會(huì)收到騰訊下發(fā)的開戶郵件，郵件中包含商戶平臺(tái)的賬號(hào)、密碼等重要信息。

appid：商戶通過微信管理后臺(tái)，申請(qǐng)服務(wù)號(hào)、訂閱號(hào)、小程序或APP應(yīng)用成功之后，微信會(huì)為每個(gè)應(yīng)用分配一個(gè)唯一標(biāo)識(shí)id。

openid：用戶在公眾號(hào)內(nèi)的身份標(biāo)識(shí)，一旦確認(rèn)，不會(huì)再變；同一用戶在不同公眾號(hào)擁有不同的openid。商戶后臺(tái)系統(tǒng)通過登錄授權(quán)、支付通知、查詢訂單等API可獲取到用戶的openid。主要用途是判斷同一個(gè)用戶，對(duì)用戶發(fā)送客服消息、模版消息等。

微信管理后臺(tái)：微信有很多管理平臺(tái)，容易混淆，我們主要關(guān)注下面三個(gè)平臺(tái)：

1. 微信公眾平臺(tái) 微信公眾賬號(hào)申請(qǐng)入口和管理后臺(tái)。商戶可以在公眾平臺(tái)提交基本資料、業(yè)務(wù)資料、財(cái)務(wù)資料申請(qǐng)開通微信支付功能。帳號(hào)分類：服務(wù)號(hào)、訂閱號(hào)、小程序、企業(yè)微信（也叫企業(yè)號(hào)，類似于企業(yè)OA）。

2. 微信商戶平臺(tái) 微信支付相關(guān)的商戶功能集合，包括參數(shù)配置、支付數(shù)據(jù)查詢與統(tǒng)計(jì)、在線退款、代金券或立減優(yōu)惠運(yùn)營等功能。

3. 微信開放平臺(tái) 商戶APP接入微信支付開放接口的申請(qǐng)入口，通過此平臺(tái)可申請(qǐng)微信APP支付。

簽名：商戶后臺(tái)和微信支付后臺(tái)根據(jù)相同的密鑰和算法生成一個(gè)結(jié)果，用于校驗(yàn)雙方身份合法性。簽名的算法由微信支付制定并公開，常用的簽名方式有：MD5、SHA1、SHA256、HMAC等。

密鑰：作為簽名算法中的鹽，需要在微信平臺(tái)及商戶業(yè)務(wù)系統(tǒng)各存一份，要妥善保管。 key設(shè)置路徑：微信商戶平臺(tái)(http://pay.weixin.qq.com)-->賬戶設(shè)置-->API安全-->密鑰設(shè)置。