[移动开发]微信支付-超详细java开发-小程序对接

前言

本文适用于有一定基础的开发者，简单易通。后台用的的是java，我用的是springBoot，其它框架基本同理，前端就是一个简单的demo。微信官方提供了V2和V3两种方式，本文基于V2版支付开发（后续更新V3）。V2和V3版本区别

微信支付接入前准备

1.思路介绍

本次以微信小程序开发为例，如果自己想要玩一下，需要在微信公众平台注册一个小程序账号，其次微信支付
平台，进行接入微信支付，然后就可以着手开发了。（公司开发的话，参数账号之类都会提供的，不用担心）

2.如何注册小程序账号？

可以直接进入微信公众平台直接注册，也可根据文档指引进行注册。申请账号官方详细文档
如商户已拥有自己的APP，且希望该APP接入微信支付，请前往 开放平台申请

3.如何接入微信支付，需要准备哪些东西？

简单介绍一下自己的经验，重点是营业执照信息。关键这玩意怎么搞方面快捷呢。
我提供两种方案：
1.最方便的是自己注册个电商营业执照，拼多多商铺0元直接入驻即可。注册地址要和营业执照地址相同（要有房产证明等，写自己老家就行）。
2.如果自己租的房子，合同中必须体现可以作为商铺，要不然没法。 直接注册实体个体工商户，目前非常方便线下线上都可以办理-不同地方的软件不同 这里以杭州为例，直接下载浙里办-搜索个体工商户，在线办理即可。
最重要的是地址（可以借助朋友，或者租房的时候说好可以作为商铺，当然自己本地有房子咋样搞都行），其次网上那些挂靠地址等，如果你可以承担费用，自主决定。
请参考微信支付商户号申请，详细的一批。

4.小程序接入前的准备（APPID及mchid以上两步已拿到，只需配置一下API KEY即可）

官方文档指引-小程序支付
注意：API秘钥，一定要记住。最好记事本记录一下。
由于本文基于V2版支付开发，记得设置一下。

微信支付-完整代码

前端代码

index.wxml

<view class="container">
  <view class="container">
    <input type="text" bindinput="getOrderCode" style="border:1px solid #ccc;"  />
    <button type="primary" bindtap="pay">微信支付</button>
</view>
</view>

index.js

const app = getApp()

Page({
  data: {
    txtOrderCode: '',
  },
  pay: function () {
    var ordercode = this.data.txtOrderCode;
    wx.login({
      success: function (res) {
        console.log("code值是多少"+res.code)
        if (res.code) {
          wx.request({
            url: 'http://localhost:8081/wechatPay/wxPay',
            data: {
              code: res.code,//要去换取openid的登录凭证
              money: ordercode,//支付金额（主要是code和money其他都是业务参数可去掉）
              name:"",  
              idCard:"",
              post:"",
              phone:"",
              receiverInfo:"",
              duesDate:"",
              partyOrg:"",
              agyCode:"",
              agyName:"",
              orderId:""
            },
            method: 'POST',
            success: function (res) {
              console.log("是否进来方法"+res.data.package)
              //通过接口返回的data，调用此方法唤起支付页面
              wx.requestPayment({
              	//这里的参数和值基本都是固定，不用更改
                timeStamp: res.data.timeStamp,
                nonceStr: res.data.nonceStr,
                package: res.data.package,
                signType: 'MD5',
                paySign: res.data.paySign,
                success: function (res) {
                  console.log("支付成功")
                  console.log(res);
                },
                fail: function (res) {
                  console.log("支付失败");
                  wx.showToast({
                    title: '支付失败',
                    icon:'none',
                    duration:2000
                  })
                },
                complete: function (res) {
                  console.log('支付完成');
                  if (res.errMsg == 'requestPayment:ok') {
                      wx.showModal({
                          title: '提示',
                          content: '支付成功'
                      });
                    }
                  }
              })
            },
            fail: function (res) {
              wx.showToast({
                title: '调用接口失败',
                icon:'none',
                duration:2000
              })
            },

          })
        } else {
          console.log('获取用户登录态失败！' + res.errMsg)
        }
      }
    });
},
getOrderCode: function (event) {
  console.log(event)
    this.setData({
      txtOrderCode: event.detail.value
    });
},
  onLoad: function () {
    if (app.globalData.userInfo) {
      this.setData({
        userInfo: app.globalData.userInfo,
        hasUserInfo: true
      })
    } else if (this.data.canIUse){
      // 由于 getUserInfo 是网络请求，可能会在 Page.onLoad 之后才返回
      // 所以此处加入 callback 以防止这种情况
      app.userInfoReadyCallback = res => {
        this.setData({
          userInfo: res.userInfo,
          hasUserInfo: true
        })
      }
    } else {
      // 在没有 open-type=getUserInfo 版本的兼容处理
      wx.getUserInfo({
        success: res => {
          app.globalData.userInfo = res.userInfo
          this.setData({
            userInfo: res.userInfo,
            hasUserInfo: true
          })
        }
      })
    }
  },
})

效果图

后端代码

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.hn.yuan</groupId>
    <artifactId>demo_wxpay</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo_wxpay</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>

        <!--解析xml-->
        <dependency>
            <groupId>org.jdom</groupId>
            <artifactId>jdom2</artifactId>
            <version>2.0.6</version>
        </dependency>
        <!--Java对象和JSON数据之间进行映射的Java类库-->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.6</version>
        </dependency>
        <!--处理输入输出流-->
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.11.0</version>
        </dependency>

        <dependency>
            <groupId>org.bouncycastle</groupId>
            <artifactId>bcprov-jdk16</artifactId>
            <version>1.46</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.21</version>
        </dependency>

        <!--小程序支付包-->
        <dependency>
            <groupId>com.github.wechatpay-apiv3</groupId>
            <artifactId>wechatpay-apache-httpclient</artifactId>
            <version>0.4.8</version>
        </dependency>

        <!--http commons client-->
        <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <version>3.1</version>
        </dependency>

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.0</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>2.1</version>
        </dependency>


        <!--springboot整合redisCluster-->
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
        </dependency>
        <!--redis框架-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

server:
  port: 8081

spring:
    datasource:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/yuan_productlist?useUnicode=true&characterEncoding=UTF-8&useSSL=false
        username: root
        password: root
# 配置slq打印日志
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

log.path: F:/logs	#打印日志路径

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <!--注意resource属于.yml还是.properties-->
    <property resource="application.yml"/>
    <!--定义日志文件的存储地址 勿在 LogBack 的配置中使用相对路径     使用spring-boot的配置项LOG_PATH-->
    <springProperty scope="context" name="LOG_HOME" source="log.path"/>
    <!--下面用于application.properties-->
    <!--    <property name="LOG_HOME" value="${log.path}" />-->
    <property name="LOG_LEVEL" value="INFO" />
    <!-- 控制台输出 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符-->
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
    </appender>
    <!-- 按照每天生成日志文件 -->
    <appender name="FILE"  class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!--日志文件输出的文件名-->
            <FileNamePattern>${LOG_HOME}/springbootjpa.log.%d{yyyy-MM-dd}.log</FileNamePattern>
            <!--日志文件保留天数-->
            <MaxHistory>30</MaxHistory>
        </rollingPolicy>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符-->
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
        <!--日志文件最大的大小-->
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <MaxFileSize>10MB</MaxFileSize>
        </triggeringPolicy>
    </appender>

    <logger name="com.wm.springbootjpa01" level="INFO"/>
    <logger name="org.apache.ibatis" level="${LOG_LEVEL}"/>
    <logger name="org.mybatis.spring" level="${LOG_LEVEL}"/>
    <logger name="org.springframework" level="${LOG_LEVEL}"/>
    <logger name="java.sql.Connection" level="${LOG_LEVEL}"/>
    <logger name="java.sql.Statement" level="${LOG_LEVEL}"/>
    <logger name="java.sql.PreparedStatement" level="${LOG_LEVEL}"/>

    <!--设置为OFF,即屏蔽; 留下sqltiming作为INFO级别输出-->
    <logger name="jdbc.connection" level="OFF"/>
    <logger name="jdbc.resultset" level="OFF"/>
    <logger name="jdbc.resultsettable" level="OFF"/>
    <logger name="jdbc.audit" level="OFF"/>
    <logger name="jdbc.sqltiming" level="INFO"/>
    <logger name="jdbc.sqlonly" level="OFF"/>

    <!-- 日志输出级别 -->
    <root level="${LOG_LEVEL}">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    </root>
</configuration>

WechatConfig支付配置类

package com.hn.yuan.wxinterface;

/**
 * 支付配置类
 * @author XIAOCAO
 **/
public class WechatConfig {
    //小程序appid(开发者在微信公众平台查询)
    public static final String appid ="";
    //小程序appkey(开发者在微信公众平台查询)
    public static final String APP_SECRET="";
    //微信支付的商户id(开发者在微信商户平台查询)
    public static final String mch_id = "";
    //微信支付的商户密钥(开发者在微信商户平台查询)
    public static final String key = "";
    //支付成功后的服务器回调url（后台随便的一个接口能接收到就行，有效地址）
    public static final String notify_url = "";
    //签名方式，固定值
    public static final String SIGNTYPE = "MD5";
    //交易类型，小程序支付的固定值为JSAPI
    public static final String TRADETYPE = "JSAPI";
    //微信统一下单接口地址
    public static final String pay_url = "https://api.mch.weixin.qq.com/pay/unifiedorder";
}

WxPayDto类

package com.hn.yuan.entity;

import lombok.Data;

import java.io.Serializable;


@Data
public class WxPayDto implements Serializable {

    private static final long serialVersionUID = 1L;
    private String partyOrg;
    private String duesDate;
    private String money;   //缴费金额
    private String name;
    private String idCard;
    private String post;
    private String phone;
    private String orderId;
    private String receiverInfo;
    private String code;//获取openid临时凭证
    private String agyCode;
    private String agyName;

}

业务代码WxpayController

package com.hn.yuan.controller;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.hn.yuan.entity.WxPayDto;
import com.hn.yuan.wxinterface.*;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.math.BigDecimal;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.Map;

import static com.hn.yuan.wxinterface.WXPayConstants.RETURN_CODE;
import static com.hn.yuan.wxinterface.WechatConfig.APP_SECRET;

@CrossOrigin
@RestController
@RequestMapping("/wechatPay")
public class WxpayController {
    private static Logger logger = LoggerFactory.getLogger(WxpayController.class);

    @Autowired
    private HttpServletRequest request;

    @Resource
    private HttpServletResponse response;


    @PostMapping("/wxPay")
    public String wxPay(@RequestBody WxPayDto dto) {
        System.out.println("进来方法了");
        Object result = new Object();
        try {
            //获取客户端的ip地址
            String spbill_create_ip = getIpAddr(request);
            System.out.println("客户端Ip地址" + spbill_create_ip);
            System.out.println("code是什么样式的" + dto.getCode());
            //获取openid
            String openid = getOpenId(dto.getCode());
            //订单号  uuid  随机生成
            String outTradeNo = WXPayUtil.generateUUID();
            //支付业务
            result = wxPay(spbill_create_ip, openid, outTradeNo, dto);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return PayUtil.toJson(result);
    }


    //获取IP
    private String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            //多次反向代理后会有多个ip值，第一个ip才是真实ip
            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();
    }

    /**
     * 缴纳费用
     **/
    public Map wxPay(String spbill_create_ip, String openId, String orderNumber, WxPayDto dto) {
        Map<String, String> payMap = new HashMap<String, String>();//返回给小程序端需要的参数
        try {
            logger.info("【小程序支付】 统一下单开始, 订单编号=" + orderNumber);
            //商品名称
            String body = dto.getAgyName() + "-" + dto.getName() + "-测试费用";
            //获取客户端的ip地址
            BigDecimal money = new BigDecimal(dto.getMoney());
            //组装参数，用户生成统一下单接口的签名
            logger.info("----------下单接口签名-------");
            Map<String, String> packageParams = new HashMap<>();
            //微信分配的小程序ID
            packageParams.put("appid", WechatConfig.appid);
            //微信支付分配的商户号
            packageParams.put("mch_id", WechatConfig.mch_id);
            //随机字符串
            packageParams.put("nonce_str", System.currentTimeMillis() / 1000 + "");
            //签名类型
            packageParams.put("sign_type", "MD5");
            //充值订单 商品描述
            packageParams.put("body", body);
            //商户订单号
            packageParams.put("out_trade_no", orderNumber);
            //订单总金额，单位为分
            packageParams.put("total_fee", money.multiply(BigDecimal.valueOf(100)).intValue() + "");
            //终端IP
            packageParams.put("spbill_create_ip", spbill_create_ip);
            //通知回调地址
            packageParams.put("notify_url", WechatConfig.notify_url);
            //交易类型
            packageParams.put("trade_type", WechatConfig.TRADETYPE);
            //用户标识
            packageParams.put("openid", openId);
            //第一次签名
            String sign = WXPayUtil.generateSignature(packageParams, WechatConfig.key);
            System.out.println("第一签名打印的是个啥" + sign);
            packageParams.put("sign", sign);
            System.out.println("字符串是啥" + PaymentKit.toXml(packageParams));
            //调用支付定义下单API,返回预付单信息 prepay_id
            String result = HttpKit.post(WechatConfig.pay_url, PaymentKit.toXml(packageParams));
            logger.info("调试模式_统一下单接口 返回XML数据：" + result);
            // 将解析结果存储在HashMap中
            Map<String, String> map = PaymentKit.xmlToMap(result);
            String return_code = map.get("return_code");//返回状态码
            String result_code = map.get("result_code");//返回状态码
            if (return_code.equals("SUCCESS") || return_code.equals(result_code)) {
                //返回的预付单信息
                String prepay_id = map.get("prepay_id");
                payMap.put("appId", WechatConfig.appid);
                payMap.put("timeStamp", System.currentTimeMillis() / 1000 + "");
                payMap.put("nonceStr", System.currentTimeMillis() + "");
                payMap.put("package", "prepay_id=" + prepay_id);
                payMap.put("signType", "MD5");

                //再次签名，这个签名用于小程序端调用wx.requesetPayment方法
                String paySign = WXPayUtil.generateSignature(payMap, WechatConfig.key);
                System.out.println("第二签名打印的是个啥" + sign);
                logger.info("=======================第二次签名：", paySign + "============ ======");
                payMap.put("paySign", paySign);
                payMap.put("status", "success");
                //更新订单信息
            } else {
                logger.info("----------统一下单失败-------");
                payMap.put("status", "error");
                return payMap;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return payMap;
    }

    /**
     * 小程序获取openid
     *
     * @return
     */
    public static String getOpenId(String code) throws NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
        RestTemplate restTemplate = new RestTemplate();
        String url = "https://api.weixin.qq.com/sns/jscode2session?appid=" + WechatConfig.appid + "&secret=" + APP_SECRET + "&js_code=" + code + "&grant_type=authorization_code";
        ResponseEntity<String> responseEntity =
                restTemplate.getForEntity(url, String.class);
        String body = responseEntity.getBody();
        JSONObject object = JSON.parseObject(body);
        String openId = object.getString("openid");// 获取openId
        System.out.println("该用户的openid——>" + openId);
        return openId;
    }


    /**
     * 功能描述: <小程序回调>
     *
     * @return:
     **/
    @GetMapping("/wxProPayNotify")
    public void wxProPayNotify() throws Exception {
        logger.info("进入微信小程序支付回调");
        String xmlMsg = HttpKit.readData(request);
        logger.info("微信小程序通知信息" + xmlMsg);
        Map<String, String> resultMap = PaymentKit.xmlToMap(xmlMsg);
        if (resultMap.get(RETURN_CODE).equals("SUCCESS")) {
            String orderNo = resultMap.get("out_trade_no");
            logger.info("微信小程序支付成功,订单号{}", orderNo);
            //通过订单号 修改数据库中的记录,业务操作
        }
        String result = "<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>";
        try {
            response.getWriter().write(result);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

工具类

• http,https-request类

package com.hn.yuan.wxinterface;

import javax.net.ssl.*;
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.Iterator;
import java.util.Map;

/**
 * http,https-request类
 **/
public class HttpKit {
    private static String CHARSET = "UTF-8";
    private static final SSLSocketFactory sslSocketFactory = initSSLSocketFactory();
    private static final TrustAnyHostnameVerifier trustAnyHostnameVerifier = new HttpKit().new TrustAnyHostnameVerifier();

    private HttpKit() {
    }

    private static SSLSocketFactory initSSLSocketFactory() {
        try {
            TrustManager[] e = new TrustManager[]{new HttpKit().new TrustAnyTrustManager()};
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init((KeyManager[])null, e, new SecureRandom());
            return sslContext.getSocketFactory();
        } catch (Exception var2) {
            throw new RuntimeException(var2);
        }
    }

    public static void setCharSet(String charSet) {
        if(charSet!=null && !charSet.equals("")) {
            throw new IllegalArgumentException("charSet can not be blank.");
        } else {
            CHARSET = charSet;
        }
    }

    private static HttpURLConnection getHttpConnection(String url, String method, Map<String, String> headers) throws IOException, NoSuchAlgorithmException, NoSuchProviderException, KeyManagementException {
        URL _url = new URL(url);
        HttpURLConnection conn = (HttpURLConnection)_url.openConnection();
        if(conn instanceof HttpsURLConnection) {
            ((HttpsURLConnection)conn).setSSLSocketFactory(sslSocketFactory);
            ((HttpsURLConnection)conn).setHostnameVerifier(trustAnyHostnameVerifier);
        }

        conn.setRequestMethod(method);
        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setConnectTimeout(19000);
        conn.setReadTimeout(19000);
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("AuthUser-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36");
        if(headers != null && !headers.isEmpty()) {
            Iterator i$ = headers.entrySet().iterator();

            while(i$.hasNext()) {
                Map.Entry entry = (Map.Entry)i$.next();
                conn.setRequestProperty((String)entry.getKey(), (String)entry.getValue());
            }
        }

        return conn;
    }

    public static String get(String url, Map<String, String> queryParas, Map<String, String> headers) {
        HttpURLConnection conn = null;
        String e;
        try {
            conn = getHttpConnection(buildUrlWithQueryString(url, queryParas), "GET", headers);
            conn.connect();
            e = readResponseString(conn);
        } catch (Exception var8) {
            throw new RuntimeException(var8);
        } finally {
            if(conn != null) {
                conn.disconnect();
            }
        }
        return e;
    }

    public static String get(String url, Map<String, String> queryParas) {
        return get(url, queryParas, (Map)null);
    }

    public static String get(String url) {
        return get(url, (Map)null, (Map)null);
    }

    public static String post(String url, Map<String, String> queryParas, String data, Map<String, String> headers) {
        HttpURLConnection conn = null;

        String var6;
        try {
            conn = getHttpConnection(buildUrlWithQueryString(url, queryParas), "POST", headers);
            conn.connect();
            OutputStream e = conn.getOutputStream();
            e.write(data.getBytes(CHARSET));
            e.flush();
            e.close();
            var6 = readResponseString(conn);
        } catch (Exception var10) {
            throw new RuntimeException(var10);
        } finally {
            if(conn != null) {
                conn.disconnect();
            }
        }
        return var6;
    }

    public static String post(String url, Map<String, String> queryParas, String data) {
        return post(url, queryParas, data, (Map)null);
    }

    public static String post(String url, String data, Map<String, String> headers) {
        return post(url, (Map)null, data, headers);
    }

    public static String post(String url, String data) {
        return post(url, (Map)null, data, (Map)null);
    }

    private static String readResponseString(HttpURLConnection conn) {
        StringBuilder sb = new StringBuilder();
        InputStream inputStream = null;

        try {
            inputStream = conn.getInputStream();
            BufferedReader e = new BufferedReader(new InputStreamReader(inputStream, CHARSET));
            String line = null;

            while((line = e.readLine()) != null) {
                sb.append(line).append("\n");
            }

            String var5 = sb.toString();
            return var5;
        } catch (Exception var14) {
            throw new RuntimeException(var14);
        } finally {
            if(inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException var13) {
                }
            }

        }
    }

    private static String buildUrlWithQueryString(String url, Map<String, String> queryParas) {
        if(queryParas != null && !queryParas.isEmpty()) {
            StringBuilder sb = new StringBuilder(url);
            boolean isFirst;
            if(url.indexOf("?") == -1) {
                isFirst = true;
                sb.append("?");
            } else {
                isFirst = false;
            }

            String key;
            String value;
            for(Iterator i$ = queryParas.entrySet().iterator(); i$.hasNext(); sb.append(key).append("=").append(value)) {
                Map.Entry entry = (Map.Entry)i$.next();
                if(isFirst) {
                    isFirst = false;
                } else {
                    sb.append("&");
                }

                key = (String)entry.getKey();
                value = (String)entry.getValue();
                if(value!=null && !value.equals("")) {
                    try {
                        value = URLEncoder.encode(value, CHARSET);
                    } catch (UnsupportedEncodingException var9) {
                        throw new RuntimeException(var9);
                    }
                }
            }

            return sb.toString();
        } else {
            return url;
        }
    }

    public static String readData(HttpServletRequest request) {
        BufferedReader br = null;

        try {
            StringBuilder e = new StringBuilder();
            br = request.getReader();
            String line = null;

            while((line = br.readLine()) != null) {
                e.append(line).append("\n");
            }

            line = e.toString();
            return line;
        } catch (IOException var12) {
            throw new RuntimeException(var12);
        } finally {
            if(br != null) {
                try {
                    br.close();
                } catch (IOException var11) {
                }
            }

        }
    }

    /** @deprecated */
    @Deprecated
    public static String readIncommingRequestData(HttpServletRequest request) {
        return readData(request);
    }


    private class TrustAnyTrustManager implements X509TrustManager {
        private TrustAnyTrustManager() {
        }

        public X509Certificate[] getAcceptedIssuers() {
            return null;
        }

        public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        }

        public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        }
    }

    private class TrustAnyHostnameVerifier implements HostnameVerifier {
        private TrustAnyHostnameVerifier() {
        }

        public boolean verify(String hostname, SSLSession session) {
            return true;
        }
    }


}

• 微信支付api

package com.hn.yuan.wxinterface;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;


/**
 * 微信支付api
 * @author XIAOCAO
 * @version 2020/12/25
 **/
public class PaymentApi {

    private PaymentApi() {}

    // 文档地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_1
    private static String unifiedOrderUrl = "https://api.mch.weixin.qq.com/pay/unifiedorder";

    /**
     * 交易类型枚举
     * WAP的文档：https://pay.weixin.qq.com/wiki/doc/api/wap.php?chapter=15_1
     * @author L.cm
     * <pre>
     * email: 596392912@qq.com
     * site: http://www.dreamlu.net
     * date: 2015年10月27日 下午9:46:27
     * </pre>
     */
    public enum TradeType {
        JSAPI, NATIVE, APP, WAP, MWEB
    }

    /**
     * 统一下单
     * @param params 参数map
     * @return String
     */
    public static String pushOrder(Map<String, String> params) {
        return HttpKit.post(unifiedOrderUrl, PaymentKit.toXml(params));
    }

    private static Map<String, String> request(String url, Map<String, String> params, String paternerKey) {
        params.put("nonce_str", System.currentTimeMillis() + "");
        String sign = PaymentKit.createSign(params, paternerKey);
        params.put("sign", sign);
        String xmlStr = HttpKit.post(url, PaymentKit.toXml(params));
        return PaymentKit.xmlToMap(xmlStr);
    }

    /**
     * 文档说明：https://pay.weixin.qq.com/wiki/doc/api/wap.php?chapter=15_4
     * <pre>
     * @param appId 公众账号ID         是    String(32)    wx8888888888888888    微信分配的公众账号ID
     * 随机字符串         noncestr    是    String(32)    5K8264ILTKCH16CQ2502SI8ZNMTM67VS    随机字符串，不长于32位。推荐随机数生成算法
     * 订单详情扩展字符串    package        是    String(32)    WAP    扩展字段，固定填写WAP
     * @param prepayId 预支付交易会话标识    是    String(64)    wx201410272009395522657a690389285100    微信统一下单接口返回的预支付回话标识，用于后续接口调用中使用，该值有效期为2小时
     * 签名                 sign        是    String(32)    C380BEC2BFD727A4B6845133519F3AD6    签名，详见签名生成算法
     * 时间戳            timestamp    是    String(32)    1414561699    当前的时间，其他详见时间戳规则
     * @param paternerKey 签名密匙
     * </pre>
     * @return {String}
     */
    public static String getDeepLink(String appId, String prepayId, String paternerKey) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("appid", appId);
        params.put("noncestr", System.currentTimeMillis() + "");
        params.put("package", "WAP");
        params.put("prepayid", prepayId);
        params.put("timestamp", System.currentTimeMillis() / 1000 + "");
        String sign = PaymentKit.createSign(params, paternerKey);
        params.put("sign", sign);

        String string1 = PaymentKit.packageSign(params, true);

        String string2 = "";
        try { string2 = PaymentKit.urlEncode(string1); } catch (UnsupportedEncodingException e) {}

        return "weixin://wap/pay?" + string2;
    }

    // 文档地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_2
    private static String orderQueryUrl = "https://api.mch.weixin.qq.com/pay/orderquery";

    /**
     * 根据商户订单号查询信息
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param transaction_id 微信订单号
     * @return 回调信息
     */
    public static Map<String, String> queryByTransactionId(String appid, String mch_id, String paternerKey, String transaction_id) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("appid", appid);
        params.put("mch_id", mch_id);
        params.put("transaction_id", transaction_id);
        return request(orderQueryUrl, params, paternerKey);
    }

    /**
     * 根据商户订单号查询信息
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param out_trade_no 商户订单号
     * @return 回调信息
     */
    public static Map<String, String> queryByOutTradeNo(String appid, String mch_id, String paternerKey, String out_trade_no) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("appid", appid);
        params.put("mch_id", mch_id);
        params.put("out_trade_no", out_trade_no);
        return request(orderQueryUrl, params, paternerKey);
    }

    // 文档地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_3
    private static String closeOrderUrl = "https://api.mch.weixin.qq.com/pay/closeorder";

    /**
     * 关闭订单
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param out_trade_no 商户订单号
     * @return 回调信息
     */
    public static Map<String, String> closeOrder(String appid, String mch_id, String paternerKey, String out_trade_no) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("appid", appid);
        params.put("mch_id", mch_id);
        params.put("out_trade_no", out_trade_no);
        return request(closeOrderUrl, params, paternerKey);
    }

    // 申请退款文档地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_4
    public static String refundUrl = "https://api.mch.weixin.qq.com/secapi/pay/refund";

//    /**
//     * 申请退款，内部添加了随机字符串nonce_str和签名sign
//     * @param params 参数map，内部添加了随机字符串nonce_str和签名sign
//     * @param paternerKey 商户密钥
//     * @param certPath 证书文件目录
//     * @return  map
//     */
//    public static Map<String, String> refund(Map<String, String> params, String paternerKey, String certPath) {
//        params.put("nonce_str", System.currentTimeMillis() + "");
//        String sign = PaymentKit.createSign(params, paternerKey);
//        params.put("sign", sign);
//        String partner = params.get("mch_id");
//        String xmlStr = HttpKit.delegate.postSSL(refundUrl, PaymentKit.toXml(params), certPath, partner);
//        return PaymentKit.xmlToMap(xmlStr);
//    }

    // 查询退款文档地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_5
    private static String refundQueryUrl = "https://api.mch.weixin.qq.com/pay/refundquery";

    private static Map<String, String> baseRefundQuery(Map<String, String> params, String appid, String mch_id, String paternerKey) {
        params.put("appid", appid);
        params.put("mch_id", mch_id);
        return request(refundQueryUrl, params, paternerKey);
    }

    /**
     * 根据微信订单号查询退款
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param transaction_id 微信订单号
     * @return map
     */
    public static Map<String, String> refundQueryByTransactionId(String appid, String mch_id, String paternerKey, String transaction_id) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("transaction_id", transaction_id);
        return baseRefundQuery(params, appid, mch_id, paternerKey);
    }

    /**
     * 根据微信订单号查询退款
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param out_trade_no 商户订单号
     * @return map
     */
    public static Map<String, String> refundQueryByOutTradeNo(String appid, String mch_id, String paternerKey, String out_trade_no) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("out_trade_no", out_trade_no);
        return baseRefundQuery(params, appid, mch_id, paternerKey);
    }

    /**
     * 根据微信订单号查询退款
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param out_refund_no 商户退款单号
     * @return map
     */
    public static Map<String, String> refundQueryByOutRefundNo(String appid, String mch_id, String paternerKey, String out_refund_no) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("out_refund_no", out_refund_no);
        return baseRefundQuery(params, appid, mch_id, paternerKey);
    }

    /**
     * 根据微信订单号查询退款
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 商户密钥
     * @param refund_id 微信退款单号
     * @return map
     */
    public static Map<String, String> refundQueryByRefundId(String appid, String mch_id, String paternerKey, String refund_id) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("refund_id", refund_id);
        return baseRefundQuery(params, appid, mch_id, paternerKey);
    }

    private static String downloadBillUrl = "https://api.mch.weixin.qq.com/pay/downloadbill";

    /**
     * <pre>
     * ALL，返回当日所有订单信息，默认值
     * SUCCESS，返回当日成功支付的订单
     * REFUND，返回当日退款订单
     * REVOKED，已撤销的订单
     * </pre>
     */
    public static enum BillType {
        ALL, SUCCESS, REFUND, REVOKED
    }

    /**
     * 下载对账单
     * <pre>
     * 公众账号ID    appid        是    String(32)    wx8888888888888888    微信分配的公众账号ID（企业号corpid即为此appId）
     * 商户号        mch_id        是    String(32)    1900000109    微信支付分配的商户号
     * 设备号        device_info    否    String(32)    013467007045764    微信支付分配的终端设备号
     * 随机字符串    nonce_str    是    String(32)    5K8264ILTKCH16CQ2502SI8ZNMTM67VS    随机字符串，不长于32位。推荐随机数生成算法
     * 签名        sign        是    String(32)    C380BEC2BFD727A4B6845133519F3AD6    签名，详见签名生成算法
     * 对账单日期    bill_date    是    String(8)    20140603    下载对账单的日期，格式：20140603
     * 账单类型        bill_type    否    String(8)
     * </pre>
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 签名密匙
     * @param billDate 对账单日期
     * @return String
     */
    public static Map<String,String> downloadBill(String appid, String mch_id, String paternerKey, String billDate) {
        return downloadBill(appid, mch_id, paternerKey, billDate, null);
    }

    /**
     * 下载对账单
     * <pre>
     * 公众账号ID    appid        是    String(32)    wx8888888888888888    微信分配的公众账号ID（企业号corpid即为此appId）
     * 商户号        mch_id        是    String(32)    1900000109    微信支付分配的商户号
     * 设备号        device_info    否    String(32)    013467007045764    微信支付分配的终端设备号
     * 随机字符串    nonce_str    是    String(32)    5K8264ILTKCH16CQ2502SI8ZNMTM67VS    随机字符串，不长于32位。推荐随机数生成算法
     * 签名        sign        是    String(32)    C380BEC2BFD727A4B6845133519F3AD6    签名，详见签名生成算法
     * 对账单日期    bill_date    是    String(8)    20140603    下载对账单的日期，格式：20140603
     * 账单类型        bill_type    否    String(8)
     * </pre>
     * @param appid 公众账号ID
     * @param mch_id 商户号
     * @param paternerKey 签名密匙
     * @param billDate 对账单日期
     * @param billType 账单类型
     * @return String
     */
    public static Map<String,String> downloadBill(String appid, String mch_id, String paternerKey, String billDate, BillType billType) {
        Map<String, String> params = new HashMap<String, String>();
        params.put("appid", appid);
        params.put("mch_id", mch_id);
        params.put("nonce_str", System.currentTimeMillis() + "");
        params.put("bill_date", billDate);
        if (null != billType) {
            params.put("bill_type", billType.name());
        } else {
            params.put("bill_type", BillType.ALL.name());
        }
        String sign = PaymentKit.createSign(params, paternerKey);
        params.put("sign", sign);
        String str = HttpKit.post(downloadBillUrl, PaymentKit.toXml(params));
        return PaymentKit.xmlToMap(str);

    }

}

• 微信支付的统一下单工具类

package com.hn.yuan.wxinterface;


import org.apache.commons.io.Charsets;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;



/**
 * 微信支付的统一下单工具类
 * @author XIAOCAO
 * @version 2020/12/24
 **/
public class PaymentKit {

    /**
     * 组装签名的字段
     * @param params 参数
     * @param urlEncoder 是否urlEncoder
     * @return String
     */
    public static String packageSign(Map<String, String> params, boolean urlEncoder) {
        // 先将参数以其参数名的字典序升序进行排序
        TreeMap<String, String> sortedParams = new TreeMap<String, String>(params);
        // 遍历排序后的字典，将所有参数按"key=value"格式拼接在一起
        StringBuilder sb = new StringBuilder();
        boolean first = true;
        for (Entry<String, String> param : sortedParams.entrySet()) {
            String value = param.getValue();
            if (Tools.isEmpty(value)) {
                continue;
            }
            if (first) {
                first = false;
            } else {
                sb.append("&");
            }
            sb.append(param.getKey()).append("=");
            if (urlEncoder) {
                try { value = urlEncode(value); } catch (UnsupportedEncodingException e) {}
            }
            sb.append(value);
        }
        return sb.toString();
    }

    /**
     * urlEncode
     * @param src 微信参数
     * @return String
     * @throws UnsupportedEncodingException 编码错误
     */
    public static String urlEncode(String src) throws UnsupportedEncodingException {
        return URLEncoder.encode(src, Charsets.UTF_8.name()).replace("+", "%20");
    }

    /**
     * 生成签名
     * @param params 参数
     * @param paternerKey 支付密钥
     * @return sign
     */
    public static String createSign(Map<String, String> params, String paternerKey) {
        // 生成签名前先去除sign
        params.remove("sign");
        String stringA = packageSign(params, false);
        String stringSignTemp = stringA + "&key=" + paternerKey;
        return Tools.md5(stringSignTemp).toUpperCase();
    }

    /**
     * 支付异步通知时校验sign
     * @param params 参数
     * @param paternerKey 支付密钥
     * @return {boolean}
     */
    public static boolean verifyNotify(Map<String, String> params, String paternerKey){
        String sign = params.get("sign");
        String localSign = PaymentKit.createSign(params, paternerKey);
        return sign.equals(localSign);
    }

    /**
     * 微信下单，map to xml
     * @param params 参数
     * @return String
     */
    public static String toXml(Map<String, String> params) {
        StringBuilder xml = new StringBuilder();
        xml.append("<xml>");
        for (Entry<String, String> entry : params.entrySet()) {
            String key   = entry.getKey();
            String value = entry.getValue();
            // 略过空值
            if (Tools.isEmpty(value)) continue;
            xml.append("<").append(key).append(">");
            xml.append(entry.getValue());
            xml.append("</").append(key).append(">");
        }
        xml.append("</xml>");
        return xml.toString();
    }

    /**
     * 针对支付的xml，没有嵌套节点的简单处理
     * @param xmlStr xml字符串
     * @return map集合
     */
    public static Map<String, String> xmlToMap(String xmlStr) {
        XmlHelper xmlHelper = XmlHelper.of(xmlStr);
        return xmlHelper.toMap();
    }

}

• 支付签名常用类

package com.hn.yuan.wxinterface;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import org.apache.commons.codec.digest.DigestUtils;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.*;

/**
 * 支付签名常用类
 * @author XIAOCAO
 * @version 2020/12/24
 **/
public class PayUtil {
    /**
     * 签名字符串
     *
     * @param text          需要签名的字符串
     * @param key           密钥
     * @param input_charset 编码格式
     * @return 签名结果
     */
    public static String sign(String text, String key, String input_charset) {
        text = text + "&key=" + key;
        return DigestUtils.md5Hex(getContentBytes(text, input_charset));
    }

    /**
     * 签名字符串
     *
     * @param text          需要签名的字符串
     * @param sign          签名结果
     * @param key           密钥
     * @param input_charset 编码格式
     * @return 签名结果
     */
    public static boolean verify(String text, String sign, String key, String input_charset) {
        text = text +"&key=" + key;
        String mysign = DigestUtils.md5Hex(getContentBytes(text, input_charset)).toUpperCase();
        if (mysign.equals(sign)) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * @param content
     * @param charset
     * @return
     * @throws java.security.SignatureException
     * @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签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:" + charset);
        }
    }

    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;// 简体中文汉字编码
        return false;
    }

    /**
     * 除去数组中的空值和签名参数
     *
     * @param sArray 签名参数组
     * @return 去掉空值与签名参数后的新签名参数组
     */
    public static Map<String, String> paraFilter(Map<String, String> sArray) {
        Map<String, String> result = new HashMap<String, String>();
        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;
    }

    /**
     * 把数组所有元素排序，并按照“参数=参数值”的模式用“&”字符拼接成字符串
     *
     * @param params 需要排序并参与字符拼接的参数组
     * @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) {// 拼接时，不包括最后一个&字符
                prestr = prestr + key + "=" + value;
            } else {
                prestr = prestr + key + "=" + value + "&";
            }
        }
        return prestr;
    }

    /**
     * @param requestUrl    请求地址
     * @param requestMethod 请求方法
     * @param outputStr     参数
     */
    public static String httpRequest(String requestUrl, String requestMethod, String outputStr) {
        // 创建SSLContext
        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();
            //往服务器端写内容
            if (null != outputStr) {
                OutputStream os = conn.getOutputStream();
                os.write(outputStr.getBytes("utf-8"));
                os.close();
            }
            // 读取服务器端返回的内容
            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();
        }
        return buffer.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,返回第一级元素键值对。如果第一级元素有子节点，则此节点的值是子节点的xml数据。
     *
     * @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);
        }

        //关闭流
        in.close();

        return m;
    }

    /**
     * 获取子结点的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());
    }

    /**
     * java对象转字符串
     * @param <T> 泛型占位符
     * @param obj T
     * @return String
     */
    public static <T> String toJson(T obj) {
        Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd HH:mm:ss").enableComplexMapKeySerialization().create();
        return gson.toJson(obj);
    }
}

• 支付常量

package com.hn.yuan.wxinterface;


/**
 * 支付常量
 *
 * @author XIAOCAO
 * @version 2020/12/24
 **/
public class WXPayConstants {

    public enum SignType {
        MD5, HMACSHA256
    }

    public static final String DOMAIN_API = "api.mch.weixin.qq.com";
    public static final String DOMAIN_API2 = "api2.mch.weixin.qq.com";
    public static final String DOMAIN_APIHK = "apihk.mch.weixin.qq.com";
    public static final String DOMAIN_APIUS = "apius.mch.weixin.qq.com";


    public static final String FAIL = "FAIL";
    /**
     * 成功的标识
     */
    public static final String SUCCESS = "SUCCESS";
    /**
     * 返回状态码的变量名
     */
    public static final String RETURN_CODE = "return_code";
    public static final String HMACSHA256 = "HMAC-SHA256";
    public static final String MD5 = "MD5";

    public static final String FIELD_SIGN = "sign";
    public static final String FIELD_SIGN_TYPE = "sign_type";

    public static final String MICROPAY_URL_SUFFIX = "/pay/micropay";
    public static final String UNIFIEDORDER_URL_SUFFIX = "/pay/unifiedorder";
    public static final String ORDERQUERY_URL_SUFFIX = "/pay/orderquery";
    public static final String REVERSE_URL_SUFFIX = "/secapi/pay/reverse";
    public static final String CLOSEORDER_URL_SUFFIX = "/pay/closeorder";
    public static final String REFUNDQUERY_URL_SUFFIX = "/pay/refundquery";
    public static final String DOWNLOADBILL_URL_SUFFIX = "/pay/downloadbill";

    // sandbox
    public static final String SANDBOX_MICROPAY_URL_SUFFIX = "/sandboxnew/pay/micropay";
    public static final String SANDBOX_UNIFIEDORDER_URL_SUFFIX = "/sandboxnew/pay/unifiedorder";
    public static final String SANDBOX_ORDERQUERY_URL_SUFFIX = "/sandboxnew/pay/orderquery";
    public static final String SANDBOX_REVERSE_URL_SUFFIX = "/sandboxnew/secapi/pay/reverse";
    public static final String SANDBOX_CLOSEORDER_URL_SUFFIX = "/sandboxnew/pay/closeorder";
    public static final String SANDBOX_REFUND_URL_SUFFIX = "/sandboxnew/secapi/pay/refund";
    public static final String SANDBOX_REFUNDQUERY_URL_SUFFIX = "/sandboxnew/pay/refundquery";
    public static final String SANDBOX_DOWNLOADBILL_URL_SUFFIX = "/sandboxnew/pay/downloadbill";
    public static final String SANDBOX_REPORT_URL_SUFFIX = "/sandboxnew/payitil/report";
    public static final String SANDBOX_SHORTURL_URL_SUFFIX = "/sandboxnew/tools/shorturl";
    public static final String SANDBOX_AUTHCODETOOPENID_URL_SUFFIX = "/sandboxnew/tools/authcodetoopenid";
}

• xpath解析xml

package com.hn.yuan.wxinterface;

import org.apache.commons.io.IOUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.namespace.QName;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.util.HashMap;
import java.util.Map;


/**
 * xpath解析xml
 * <pre>
 *     文档地址：
 *     http://www.w3school.com.cn/xpath/index.asp
 * </pre>
 * @author XIAOCAO
 * @version 2020/12/24
 **/
public class XmlHelper {
    private final XPath path;
    private final Document doc;

    private XmlHelper(InputSource inputSource) throws ParserConfigurationException, SAXException, IOException {
        DocumentBuilderFactory dbf = getDocumentBuilderFactory();
        DocumentBuilder db = dbf.newDocumentBuilder();
        doc = db.parse(inputSource);
        path = getXPathFactory().newXPath();
    }

    private static XmlHelper create(InputSource inputSource) {
        try {
            return new XmlHelper(inputSource);
        } catch (ParserConfigurationException e) {
            throw new RuntimeException(e);
        } catch (SAXException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static XmlHelper of(InputStream is) {
        InputSource inputSource = new InputSource(is);
        return create(inputSource);
    }

    public static XmlHelper of(String xmlStr) {
        StringReader sr = new StringReader(xmlStr.trim());
        InputSource inputSource = new InputSource(sr);
        XmlHelper xmlHelper = create(inputSource);
        IOUtils.closeQuietly(sr);
        return xmlHelper;
    }

    private Object evalXPath(String expression, Object item, QName returnType) {
        item = null == item ? doc : item;
        try {
            return path.evaluate(expression, item, returnType);
        } catch (XPathExpressionException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 获取String
     * @param expression 路径
     * @return String
     */
    public String getString(String expression) {
        return (String) evalXPath(expression, null, XPathConstants.STRING);
    }

    /**
     * 获取Boolean
     * @param expression 路径
     * @return String
     */
    public Boolean getBoolean(String expression) {
        return (Boolean) evalXPath(expression, null, XPathConstants.BOOLEAN);
    }

    /**
     * 获取Number
     * @param expression 路径
     * @return {Number}
     */
    public Number getNumber(String expression) {
        return (Number) evalXPath(expression, null, XPathConstants.NUMBER);
    }

    /**
     * 获取某个节点
     * @param expression 路径
     * @return {Node}
     */
    public Node getNode(String expression) {
        return (Node) evalXPath(expression, null, XPathConstants.NODE);
    }

    /**
     * 获取子节点
     * @param expression 路径
     * @return NodeList
     */
    public NodeList getNodeList(String expression) {
        return (NodeList) evalXPath(expression, null, XPathConstants.NODESET);
    }


    /**
     * 获取String
     * @param node 节点
     * @param expression 相对于node的路径
     * @return String
     */
    public String getString(Object node, String expression) {
        return (String) evalXPath(expression, node, XPathConstants.STRING);
    }

    /**
     * 获取
     * @param node 节点
     * @param expression 相对于node的路径
     * @return String
     */
    public Boolean getBoolean(Object node, String expression) {
        return (Boolean) evalXPath(expression, node, XPathConstants.BOOLEAN);
    }

    /**
     * 获取
     * @param node 节点
     * @param expression 相对于node的路径
     * @return {Number}
     */
    public Number getNumber(Object node, String expression) {
        return (Number) evalXPath(expression, node, XPathConstants.NUMBER);
    }

    /**
     * 获取某个节点
     * @param node 节点
     * @param expression 路径
     * @return {Node}
     */
    public Node getNode(Object node, String expression) {
        return (Node) evalXPath(expression, node, XPathConstants.NODE);
    }

    /**
     * 获取子节点
     * @param node 节点
     * @param expression 相对于node的路径
     * @return NodeList
     */
    public NodeList getNodeList(Object node, String expression) {
        return (NodeList) evalXPath(expression, node, XPathConstants.NODESET);
    }

    /**
     * 针对没有嵌套节点的简单处理
     * @return map集合
     */
    public Map<String, String> toMap() {
        Element root = doc.getDocumentElement();
        Map<String, String> params = new HashMap<String, String>();

        // 将节点封装成map形式
        NodeList list = root.getChildNodes();
        for (int i = 0; i < list.getLength(); i++) {
            Node node = list.item(i);
            if (node instanceof Element) {
                params.put(node.getNodeName(), node.getTextContent());
            }
        }
        return params;
    }

    private static DocumentBuilderFactory getDocumentBuilderFactory(){
        return XmlHelperHolder.documentBuilderFactory;
    }

    private static XPathFactory getXPathFactory() {
        return  XmlHelperHolder.xPathFactory;
    }

    /**
     * 内部类单例
     */
    private static class XmlHelperHolder {
        private static DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        private static XPathFactory xPathFactory = XPathFactory.newInstance();
    }

}

• 常用工具类

package com.hn.yuan.wxinterface;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.StringWriter;
import java.security.MessageDigest;
import java.util.*;


/**
 * 常用工具类
 * @author XIAOCAO
 * @version 2020/12/24
 **/
public class WXPayUtil {

    /**
     * XML格式字符串转换为Map
     *
     * @param strXML XML字符串
     * @return XML数据转换后的Map
     * @throws Exception
     */
    public static Map<String, String> xmlToMap(String strXML) throws Exception {
        try {
            Map<String, String> data = new HashMap<String, String>();
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
            InputStream stream = new ByteArrayInputStream(strXML.getBytes("UTF-8"));
            org.w3c.dom.Document doc = documentBuilder.parse(stream);
            doc.getDocumentElement().normalize();
            NodeList nodeList = doc.getDocumentElement().getChildNodes();
            for (int idx = 0; idx < nodeList.getLength(); ++idx) {
                Node node = nodeList.item(idx);
                if (node.getNodeType() == Node.ELEMENT_NODE) {
                    org.w3c.dom.Element element = (org.w3c.dom.Element) node;
                    data.put(element.getNodeName(), element.getTextContent());
                }
            }
            try {
                stream.close();
            } catch (Exception ex) {
                // do nothing
            }
            return data;
        } catch (Exception ex) {
            WXPayUtil.getLogger().warn("Invalid XML, can not convert to map. Error message: {}. XML content: {}", ex.getMessage(), strXML);
            throw ex;
        }

    }

    /**
     * 将Map转换为XML格式的字符串
     *
     * @param data Map类型数据
     * @return XML格式的字符串
     * @throws Exception
     */
    public static String mapToXml(Map<String, String> data) throws Exception {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder= documentBuilderFactory.newDocumentBuilder();
        org.w3c.dom.Document document = documentBuilder.newDocument();
        org.w3c.dom.Element root = document.createElement("xml");
        document.appendChild(root);
        for (String key: data.keySet()) {
            String value = data.get(key);
            if (value == null) {
                value = "";
            }
            value = value.trim();
            org.w3c.dom.Element filed = document.createElement(key);
            filed.appendChild(document.createTextNode(value));
            root.appendChild(filed);
        }
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        DOMSource source = new DOMSource(document);
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        StringWriter writer = new StringWriter();
        StreamResult result = new StreamResult(writer);
        transformer.transform(source, result);
        String output = writer.getBuffer().toString(); //.replaceAll("\n|\r", "");
        try {
            writer.close();
        }
        catch (Exception ex) {
        }
        return output;
    }


    /**
     * 生成带有 sign 的 XML 格式字符串
     *
     * @param data Map类型数据
     * @param key API密钥
     * @return 含有sign字段的XML
     */
    public static String generateSignedXml(final Map<String, String> data, String key) throws Exception {
        return generateSignedXml(data, key, WXPayConstants.SignType.MD5);
    }

    /**
     * 生成带有 sign 的 XML 格式字符串
     *
     * @param data Map类型数据
     * @param key API密钥
     * @param signType 签名类型
     * @return 含有sign字段的XML
     */
    public static String generateSignedXml(final Map<String, String> data, String key, WXPayConstants.SignType signType) throws Exception {
        String sign = generateSignature(data, key, signType);
        data.put(WXPayConstants.FIELD_SIGN, sign);
        return mapToXml(data);
    }


    /**
     * 判断签名是否正确
     *
     * @param xmlStr XML格式数据
     * @param key API密钥
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(String xmlStr, String key) throws Exception {
        Map<String, String> data = xmlToMap(xmlStr);
        if (!data.containsKey(WXPayConstants.FIELD_SIGN) ) {
            return false;
        }
        String sign = data.get(WXPayConstants.FIELD_SIGN);
        return generateSignature(data, key).equals(sign);
    }

    /**
     * 判断签名是否正确，必须包含sign字段，否则返回false。使用MD5签名。
     *
     * @param data Map类型数据
     * @param key API密钥
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(Map<String, String> data, String key) throws Exception {
        return isSignatureValid(data, key, WXPayConstants.SignType.MD5);
    }

    /**
     * 判断签名是否正确，必须包含sign字段，否则返回false。
     *
     * @param data Map类型数据
     * @param key API密钥
     * @param signType 签名方式
     * @return 签名是否正确
     * @throws Exception
     */
    public static boolean isSignatureValid(Map<String, String> data, String key, WXPayConstants.SignType signType) throws Exception {
        if (!data.containsKey(WXPayConstants.FIELD_SIGN) ) {
            return false;
        }
        String sign = data.get(WXPayConstants.FIELD_SIGN);
        return generateSignature(data, key, signType).equals(sign);
    }

    /**
     * 生成签名
     *
     * @param data 待签名数据
     * @param key API密钥
     * @return 签名
     */
    public static String generateSignature(final Map<String, String> data, String key) throws Exception {
        return generateSignature(data, key, WXPayConstants.SignType.MD5);
    }

    /**
     * 生成签名. 注意，若含有sign_type字段，必须和signType参数保持一致。
     *
     * @param data 待签名数据
     * @param key API密钥
     * @param signType 签名方式
     * @return 签名
     */
    public static String generateSignature(final Map<String, String> data, String key, WXPayConstants.SignType signType) throws Exception {
        Set<String> keySet = data.keySet();
        String[] keyArray = keySet.toArray(new String[keySet.size()]);
        Arrays.sort(keyArray);
        StringBuilder sb = new StringBuilder();
        for (String k : keyArray) {
            if (k.equals(WXPayConstants.FIELD_SIGN)) {
                continue;
            }
            if(data.get(k).trim().length() > 0) // 参数值为空，则不参与签名
                sb.append(k).append("=").append(data.get(k).trim()).append("&");
        }
        sb.append("key=").append(key);
        if (WXPayConstants.SignType.MD5.equals(signType)) {
            return MD5(sb.toString()).toUpperCase();
        }
        else if (WXPayConstants.SignType.HMACSHA256.equals(signType)) {
            return HMACSHA256(sb.toString(), key);
        }
        else {
            throw new Exception(String.format("Invalid sign_type: %s", signType));
        }
    }


    /**
     * 获取随机字符串 Nonce Str
     *
     * @return String 随机字符串
     */
    public static String generateNonceStr() {
        return UUID.randomUUID().toString().replaceAll("-", "").substring(0, 32);
    }


    /**
     * 生成 MD5
     *
     * @param data 待处理数据
     * @return MD5结果
     */
    public static String MD5(String data) throws Exception {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] array = md.digest(data.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (byte item : array) {
            sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
        }
        return sb.toString().toUpperCase();
    }

    /**
     * 生成 HMACSHA256
     * @param data 待处理数据
     * @param key 密钥
     * @return 加密结果
     * @throws Exception
     */
    public static String HMACSHA256(String data, String key) throws Exception {
        Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
        SecretKeySpec secret_key = new SecretKeySpec(key.getBytes("UTF-8"), "HmacSHA256");
        sha256_HMAC.init(secret_key);
        byte[] array = sha256_HMAC.doFinal(data.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (byte item : array) {
            sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
        }
        return sb.toString().toUpperCase();
    }

    /**
     * 日志
     * @return
     */
    public static Logger getLogger() {
        Logger logger = LoggerFactory.getLogger("wxpay java sdk");
        return logger;
    }

    /**
     * 获取当前时间戳，单位秒
     * @return
     */
    public static long getCurrentTimestamp() {
        return System.currentTimeMillis()/1000;
    }

    /**
     * 获取当前时间戳，单位毫秒
     * @return
     */
    public static long getCurrentTimestampMs() {
        return System.currentTimeMillis();
    }

    /**
     * 生成 uuid， 即用来标识一笔单，也用做 nonce_str
     * @return
     */
    public static String generateUUID() {
        return UUID.randomUUID().toString().replaceAll("-", "").substring(0, 32);
    }

}