JAVA接入小程序微信支付
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一、准备所需账号以及配置信息
1、在 微信公众平台 注册应用，并保存好appId和appSecret
2、在微信支付商户平台 注册一个商户，保存好mchId（商户id）、api_key(支付密钥)、以及商户证书序列号。还需要将支付商户密钥文件下载放到项目resources目录中
项目结构
（结构中包含的其他内容与支付无关）
二、开发环境
1、导入jar包
com.github.wechatpay-apiv3
wechatpay-java
0.2.10
com.github.wxpay
wxpay-sdk
0.0.3
cn.hutool
hutool-all
5.6.1
com.alibaba.fastjson2
fastjson2
2.0.26
2、在yaml文件中配置参数
wechatpay: #应用编号 正式号id appId: XXXXXX # 小程序密钥 appSecret: XXXXXX #商户号 mchId: XXXXXX # APIv3密钥（在微信支付平台中自己设置） apiV3Key: XXXXXX # 支付成功后微信官方会自动调用我们设定的接口：域名/接口名 # 支付通知回调, 本地测试内网穿透地址（仅用于做本地测试） # notifyUrl: http://84cd47.natappfree.cc/wechatPay/notify-pay # 支付通知回调, 线上域名地址（正常使用服务器配置的域名即可），小程序上线后前后端访问数据时只能用https不能用http，因此还需要为域名配置SSL证书，可根据使用的服务器查看如何配置 notifyUrl: XXXXXX # 密钥路径,resources根目录下 keyPemPath: src/main/resources/wechatPay/apiclient_key.pem certPath: src/main/resources/wechatPay/apiclient_cert.pem certP12Path: src/main/resources/wechatPay/apiclient_cert.p12 # 商户证书序列号（可在微信支付平台商户信息中查看） serialNo: XXXXXXXXXX
3、将参数注入到配置类中
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
/**
* 微信支付配置类
*/
@Component
@Data
@ConfigurationProperties(prefix = "wechatpay")
public class WechatPayConfig {
/**
* 小程序appId
*/
private String appId;
/**
* 小程序密钥
*/
private String appSecret;
/**
* 商户号（微信支付平台设置）
*/
private String mchId;
/**
* APIv3密钥（微信支付平台设置）
*/
private String apiV3Key;
/**
* 支付成功回调地址
*/
private String notifyUrl;
/**
* 商户证书序列号
*/
private String serialNo;
}
4、支付工具类（目前只有支付，没有退款和查询）
import com.alibaba.fastjson2.JSON;
import com.project.config.WechatPayConfig;
import com.wechat.pay.java.core.RSAAutoCertificateConfig;
import com.wechat.pay.java.core.notification.NotificationConfig;
import com.wechat.pay.java.core.notification.NotificationParser;
import com.wechat.pay.java.core.notification.RequestParam;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.stereotype.Service;
import org.springframework.util.FileCopyUtils;
import javax.servlet.http.HttpServletRequest;
import java.nio.charset.StandardCharsets;
import java.util.Map;
@Service
public class WxPayUtil {
private final WechatPayConfig wechatPayConfig;
@Autowired
public WxPayUtil(WechatPayConfig wechatPayConfig) {
this.wechatPayConfig = wechatPayConfig;
}
public T getNotificationParser(HttpServletRequest request, Map body, Class clazz) throws Exception {
String privateKey = loadKeyByResource("wechatPay/apiclient_key.pem");
RequestParam requestParam = new RequestParam.Builder()
.serialNumber(request.getHeader("Wechatpay-Serial"))
.nonce(request.getHeader("Wechatpay-Nonce"))
.signature(request.getHeader("Wechatpay-Signature"))
.timestamp(request.getHeader("Wechatpay-Timestamp"))
.signType(request.getHeader("Wechatpay-Signature-Type"))
.body(JSON.toJSONString(body))
.build();
NotificationConfig config = new RSAAutoCertificateConfig.Builder()
.merchantId(wechatPayConfig.getMchId())
.privateKey(privateKey)
.merchantSerialNumber(wechatPayConfig.getSerialNo())
.apiV3Key(wechatPayConfig.getApiV3Key())
.build();
NotificationParser parser = new NotificationParser(config);
return parser.parse(requestParam, clazz);
}
/**
* 通过文件路径获取文件内容
* ClassPathResource可以在jar包中运行,但不能使用其中getFile().getPath()
* @param path 文件路径
* @return 文件内容
* @throws Exception 报错信息
*/
public static String loadKeyByResource(String path) throws Exception {
ClassPathResource resource = new ClassPathResource(path);
byte[] byteArray = FileCopyUtils.copyToByteArray(resource.getInputStream());
return new String(byteArray, StandardCharsets.UTF_8);
}
}
5、service和impl
//service
public interface WechatPayService {
}
//impl
import com.project.config.WechatPayConfig;
import com.project.service.WechatPayService;
import com.project.utils.WxPayUtil;
import com.project.vo.WechatPayVo;
import com.wechat.pay.java.core.Config;
import com.wechat.pay.java.core.RSAAutoCertificateConfig;
import com.wechat.pay.java.service.payments.jsapi.JsapiServiceExtension;
import com.wechat.pay.java.service.payments.jsapi.model.Amount;
import com.wechat.pay.java.service.payments.jsapi.model.Payer;
import com.wechat.pay.java.service.payments.jsapi.model.PrepayRequest;
import com.wechat.pay.java.service.payments.jsapi.model.PrepayWithRequestPaymentResponse;
import com.wechat.pay.java.service.refund.RefundService;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
@Service
public class WechatPayServiceImpl implements WechatPayService {
public static JsapiServiceExtension jsapiServiceExtension;
public static RefundService refundService;
private final WechatPayConfig wechatPayConfig;
public static final String CNY = "CNY";
public WechatPayServiceImpl(WechatPayConfig wechatPayConfig) throws Exception {
this.wechatPayConfig = wechatPayConfig;
this.init();
}
@PostConstruct
public void init() throws Exception {
String privateKey = WxPayUtil.loadKeyByResource("wechatPay/apiclient_key.pem");
// 初始化商户配置
Config config =
new RSAAutoCertificateConfig.Builder()
.merchantId(wechatPayConfig.getMchId())
.privateKey(privateKey)
.merchantSerialNumber(wechatPayConfig.getSerialNo())
.apiV3Key(wechatPayConfig.getApiV3Key())
.build();
// 初始化服务
jsapiServiceExtension =
new JsapiServiceExtension.Builder()
.config(config)
.signType("RSA") // 不填默认为RSA
.build();
refundService = new RefundService.Builder().config(config).build();
}
/**
* JSAPI支付下单，并返回JSAPI调起支付数据
*
* // * @param details 订单描述
* // * @param outTradeNo id
* // * @param money 金额
* // * @param openId 用户openid
* // * @param orderBean 购买商品 goods、充值 charge+
*
* @return PrepayWithRequestPaymentResponse 支付信息
*/
public PrepayWithRequestPaymentResponse prepayWithRequestPayment(WechatPayVo wechatPayVo,String outTradeNo) {
PrepayRequest request = new PrepayRequest();
Amount amount = new Amount();
//支付金额
amount.setTotal((int) wechatPayVo.getPayMoney());
amount.setCurrency(CNY);
// 设置支付成功后的回调
request.setNotifyUrl(wechatPayConfig.getNotifyUrl());
request.setAmount(amount);
//支付项目的名称
request.setAttach(wechatPayVo.getName());
request.setAppid(wechatPayConfig.getAppId());
request.setMchid(wechatPayConfig.getMchId());
//自定义设置支付成功后的商户单号32位字符
request.setOutTradeNo(outTradeNo);
//订单描述
request.setDescription(wechatPayVo.getDetails());
Payer payer = new Payer();
//前端传递的openId
payer.setOpenid(wechatPayVo.getOpenId());
request.setPayer(payer);
// 调用接口
return jsapiServiceExtension.prepayWithRequestPayment(request);
}
}
6、自定义工具类（用于获取用户支付唯一标识的openId）
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.project.vo.IdCardInfo;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestBody;
import java.util.HashMap;
import java.util.Map;
@Slf4j
public class UtilClass {
/**
* 获取openid和session_key
*
* @param code 由前端传值
* @param appId
* @param appSecret
* @return
*/
public static JSONObject getOpenIdAndSessionKey(String code, String appId, String appSecret) {
JSONObject jsonObject = null;
try {
// 请求微信接口获取openid和session_key
String url = "https://api.weixin.qq.com/sns/jscode2session?appid=" + appId +
"&secret=" + appSecret + "&js_code=" + code + "&grant_type=authorization_code";
HttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(url);
HttpResponse response = httpClient.execute(httpGet);
String jsonString = EntityUtils.toString(response.getEntity());
jsonObject = JSONObject.parseObject(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
return jsonObject;
}
}
前端调起支付传递的对象参数
import lombok.Data;
/**
* 微信支付vo
*/
@Data
public class WechatPayVo {
/**
* 用户id
*/
private long userId;
/**
* 用户唯一标识
*/
private String openId;
/**
* 订单描述
*/
private String details;
/**
* 订单名称
*/
private String name;
/**
* 支付金额
*/
private double payMoney;
/**
* 支付时间（在支付成功的回调接口中获取数据后再赋值）
*/
private String payTime;
}
**注意：微信官方调用自定义的回调接口时会传递一个JSON对象，里面包含基础的支付时间、订单描述、官方的提供的交易订单号、支付成功等信息；但需要通过解密得到，因此还需要一个解密的工具类 AesUtil **
import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson2.JSONObject;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
/**
* 解密支付回调工具类
*/
public class AesUtil {
static final int KEY_LENGTH_BYTE = 32;
static final int TAG_LENGTH_BIT = 128;
private final byte[] aesKey;
/**
* 小程序支付密钥
*/
private final String APIv3Key = "";
public AesUtil(byte[] key) {
if (key.length != KEY_LENGTH_BYTE) {
throw new IllegalArgumentException("无效的ApiV3Key，长度必须为32个字节");
}
this.aesKey = key;
}
public String decryptToString(byte[] associatedData, byte[] nonce, String ciphertext)
throws GeneralSecurityException, IOException {
try {
Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
SecretKeySpec key = new SecretKeySpec(aesKey, "AES");
GCMParameterSpec spec = new GCMParameterSpec(TAG_LENGTH_BIT, nonce);
cipher.init(Cipher.DECRYPT_MODE, key, spec);
cipher.updateAAD(associatedData);
return new String(cipher.doFinal(Base64.getDecoder().decode(ciphertext)), "utf-8");
} catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
throw new IllegalStateException(e);
} catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
throw new IllegalArgumentException(e);
}
}
/**
* 解密支付回调返回的resource对象
* 包含支付的所有信息
*/
public JSONObject decryptResource(JSONObject jsonObject) {
String json = jsonObject.toString();
//解密resource对象
String associated_data = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.associated_data");
String ciphertext = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.ciphertext");
String nonce = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.nonce");
String decryptData;
try {
decryptData = new AesUtil(this.APIv3Key.getBytes(StandardCharsets.UTF_8))
.decryptToString(associated_data.getBytes(StandardCharsets.UTF_8), nonce.getBytes(StandardCharsets.UTF_8), ciphertext);
} catch (GeneralSecurityException | IOException e) {
throw new RuntimeException(e);
}
return JSONObject.parseObject(decryptData, JSONObject.class);
}
}
7、controller层
import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson2.JSONObject;
import com.project.utils.UtilClass;
import com.wechat.pay.java.service.payments.jsapi.model.PrepayWithRequestPaymentResponse;
import com.project.config.WechatPayConfig;
import com.project.service.impl.WechatPayServiceImpl;
import com.project.utils.AesUtil;
import com.project.vo.WechatPayVo;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.security.GeneralSecurityException;
import java.util.UUID;
@RestController
@Api(tags = "微信支付接口")
@RequestMapping("wechatPay")
public class WechatPayController {
@Resource
private WechatPayServiceImpl wechatPayServiceImpl;
@Resource
private WechatPayConfig wechatPayConfig;
//前端首先调用此接口获取到用户唯一标识openId，用于后续调起支付的传参
@ApiOperation("获取openid和session_key")
@GetMapping("getOpenIdAndSessionKey")
public com.alibaba.fastjson.JSONObject getOpenIdAndSessionKey(String code) {
return UtilClass.getOpenIdAndSessionKey(code, wechatPayConfig.getAppId(), wechatPayConfig.getAppSecret());
}
@ApiOperation("调起支付")
@PostMapping("pay")
public synchronized PrepayWithRequestPaymentResponse prepayWithRequestPayment(@RequestBody WechatPayVo wechatPayVo) {
String outTradeNo = UUID.randomUUID().toString().replaceAll("-", "");
return wechatPayServiceImpl.prepayWithRequestPayment(wechatPayVo, outTradeNo);
}
//支付成功后微信会自动调用此接口
@ApiOperation("支付成功的回调")
@PostMapping("notify-pay")
public Object callBackWeiXinPay(@RequestBody JSONObject jsonObject) {
try {
String key = wechatPayConfig.getApiV3Key();
String json = jsonObject.toString();
//解密 jsonObject 对象
String associated_data = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.associated_data");
String ciphertext = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.ciphertext");
String nonce = (String) JSONUtil.getByPath(JSONUtil.parse(json), "resource.nonce");
String decryptData = new AesUtil(key.getBytes(StandardCharsets.UTF_8)).decryptToString
(associated_data.getBytes(StandardCharsets.UTF_8),
nonce.getBytes(StandardCharsets.UTF_8),
ciphertext);
JSONObject decryptDataObj = JSONObject.parseObject(decryptData, JSONObject.class);
if ("支付成功".equals(decryptDataObj.get("trade_state_desc"))) {
//支付成功后的业务操作
}
} catch (GeneralSecurityException | IOException e) {
throw new RuntimeException(e);
}
return new Object();
}
}
最后在本地测试时配置的内网穿透域名可通过 NATAPP内网穿透工具 设置，可在NATAPP官网学习使用
简单步骤：
1、注册登录
2、点击购买隧道——>免费隧道
3、根据教程下载以下文件并做简单配置后双击 natapp.exe
运行完成后如下，此时红圈内则是内网穿透的域名，拼接上我们的支付回调接口后 http://84cd47.natappfree.cc/wechatPay/notify-pay 即可使用
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