【微信支付】Java实现微信APP支付流程

前言

微信登录网页授权与APP授权
微信JSAPI支付
微信APP支付
微信APP和JSAPI退款
支付宝手机网站支付
支付宝APP支付
支付宝退款
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官方文档

微信支付-APP支付文档

pay.weixin.qq.com/wiki/doc/ap…

APP端开发步骤

pay.weixin.qq.com/wiki/doc/ap…

后端代码实现

引入依赖

		<!-- 微信支付 -->
			<dependency>
				<groupId>com.github.wxpay</groupId>
				<artifactId>wxpay-sdk</artifactId>
				<version>0.0.3</version>
			</dependency>

配置参数

application.yml

# 微信相关配置
wx:
  #商户 ID（微信支付平台-账户中心-个人信息）
  MCH_ID: 
  # APP_ID(微信开放平台或公众号查找)
  A_APP_ID: 
  # 秘钥(微信开放平台或公众号查找)
  A_APP_SECRET: 
  # 支付秘钥KEY（微信支付平台-账户中心-api安全-api秘钥）
  A_KEY: 
  # 支付商户证书所载目录（微信支付平台-账户中心-api安全-API证书）
  A_CERT_PATH: 
  #支付成功回调地址
  WX_CALLBACK_URL: 

YmlParament

@Component
@Data
public class YmlParament {
	/*微信相关字段*/
	@Value("${wx.A_APP_ID}")
	private String a_app_id;
	@Value("${wx.A_APP_SECRET}")
	private String a_app_secret;
	@Value("${wx.MCH_ID}")
	private String mch_id;
	@Value("${wx.A_KEY}")
	private String a_key;
	@Value("${wx.A_CERT_PATH}")
	private String a_cert_path;
    @Value("${wx.WX_CALLBACK_URL}")
	private String wx_callback_url;

微信统一下单

微信统一下单接口文档：pay.weixin.qq.com/wiki/doc/ap…

• 初始化微信支付配置

@Component
public class WxConfig {
   @Autowired
   private YmlParament ymlParament;
   
@Bean(autowire = Autowire.BY_NAME,value = WxParament.APP_WX_PAY)
	public WXPay setAppWXPay() throws Exception {
		return new WXPay(new WxPayConfig(
				ymlParament.getA_cert_path(),
				ymlParament.getA_app_id(),
				ymlParament.getMch_id(),
				ymlParament.getA_key()));
	}

WxPayConfig

public class WxPayConfig implements WXPayConfig {
	private byte[] certData;
	private String appID;
	private String mchID;
	private String key;

	public WxPayConfig(String certPath, String appID,String mchID,String key) throws Exception {
		File file = new File(certPath);
		InputStream certStream = new FileInputStream(file);
		this.certData = new byte[(int) file.length()];
		certStream.read(this.certData);
		certStream.close();
		this.appID = appID;
		this.mchID = mchID;
		this.key = key;
	}
}

• 微信下单接口，关键代码（服务层）

@Resource(name = WxParament.APP_WX_PAY)
private WXPay wxAppPay;

/* 微信统一下单 */
   private Map<String, String> wxUnifiedOrder(String orderNo, String orderFee, String requestIp) throws RuntimeException {
      Map<String, String> data = new HashMap<String, String>();
      data.put("nonce_str", WXPayUtil.generateNonceStr());
      data.put("body", "我来下单啦");
      data.put("out_trade_no", orderNo);
      data.put("sign_type", "MD5");
      data.put("total_fee", orderFee);
      data.put("spbill_create_ip", requestIp);
      data.put("notify_url",ymlParament.getWx_callback_url());
      data.put("trade_type", "APP"); // 此处指定为APP支付
      Map<String, String> wxOrderResult = WxPay.unifiedorder(data,wxAppPay);
     if("FAIL".equals(wxOrderResult.get("return_code"))){
       throw new RuntimeException(wxOrderResult.get("return_msg"));
     }
        /* IsNull自定义，主要判断非空 */
      if (IsNull.isNull(wxOrderResult.get("prepay_id"))) {
         throw new RuntimeException("微信支付下单成功后，返回的prepay_id为空");
      }
      return wxOrderResult;

   }

@Override
public Map<String, String> insertWxAppPay(String orderNo,String orderFee, String requestIp, String openid) {
	try {
		/* 微信下单 */
		Map<String, String> wxOrderResult = wxUnifiedOrder(orderNo, orderFee, requestIp, openid);
		Map<String, String> chooseWXPay = new HashMap<>();
        /* 这里的key值都是小写的，而JSAPI是驼峰式写法 */
		chooseWXPay.put("appid", ymlParament.getA_app_id());
		chooseWXPay.put("partnerid", ymlParament.getMch_id());
		chooseWXPay.put("prepayid", wxOrderResult.get("prepay_id"));
		chooseWXPay.put("package", "Sign=WXPay");
		chooseWXPay.put("noncestr", wxOrderResult.get("nonce_str"));
		chooseWXPay.put("timestamp", WxUtils.create_timestamp());
		String signature = WXPayUtil.generateSignature(chooseWXPay, ymlParament.getA_key());
		chooseWXPay.put("sign", signature);
		return chooseWXPay;
	} catch (Exception e) {
		e.printStackTrace();
		throw new RuntimeException(e.getMessage());
	}
}

• controller层（略）

微信支付成功回调

• 关键代码

   @Resource(name = WxParament.APP_WX_PAY)
   private WXPay wxAppPay;

   @ApiOperation("微信支付回调")
   @PostMapping("callback")
   public String callback(HttpServletRequest request) throws Exception {
   	try {
   		// 1、获取参数
   		Map<String, String> params = getMapByRequest(request);
   		log.info("微信回调回来啦！！！！" + params);
   		// 2、校验
           checkCallbackWxPay(params);
   		//业务逻辑
   		return wxPaySuccess();
   	} catch (Exception e) {
   		e.printStackTrace();
   		return wxPayFail(e.getMessage());
   	}
   }
   
/**
    * 获取微信过来的请求参数
    * @param request
    * @return
    * @throws Exception
    */
   private static Map<String, String> getMapByRequest(HttpServletRequest request) throws Exception{
   	InputStream inStream = request.getInputStream();
   	ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
   	byte[] buffer = new byte[1024];
   	int len = 0;
   	while ((len = inStream.read(buffer)) != -1) {
   		outSteam.write(buffer, 0, len);
   	}
   	Map<String, String> ret= WXPayUtil.xmlToMap(new String(outSteam.toByteArray(), "utf-8"));
   	outSteam.close();
   	inStream.close();
   	return ret;
   }	
   
   /*校验 */
   private void checkCallbackWxPay(Map<String, String> params)
   		throws Exception {
   	if ("FAIL".equals(params.get("result_code"))) {
   		throw new Exception("微信支付失败");
   	}
   	if (!checkWxCallbackSing(params, wxAppPay)) {
   		throw new Exception("微信支付回调签名认证失败");
   	}
   	//校验金额
       //判断订单是否重复
       //....业务逻辑
   }
   
/**
    * 检查微信回调签名 https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_7
    * 
    * @param wp 传入：@Autowired WXPay
    */
   private static boolean checkWxCallbackSing(Map<String, String> notifyMap, WXPay wp) throws Exception {
   	return wp.isPayResultNotifySignatureValid(notifyMap);
   }

   /**
    * 微信支付返回参数结果封装
    */
   private static String wxPaySuccess() throws Exception {
   	Map<String, String> succResult = new HashMap<String, String>();
   	succResult.put("return_code", "SUCCESS");
   	succResult.put("return_msg", "OK");
   	return WXPayUtil.mapToXml(succResult);
   }
   /**
    * @param mess 错误消息提示
    * @return 微信返回错我的提示
    * @throws Exception
    */
   private static String wxPayFail(String mess) throws Exception {
   	Map<String, String> succResult = new HashMap<String, String>();
   	succResult.put("return_code", "FAIL");
   	succResult.put("return_msg", IsNull.isNull(mess)?"自定义异常错误！":mess);
   	return WXPayUtil.mapToXml(succResult);
   }

补充

如果不想验证签名，还有一种方式判断是否支付成功，就是调用微信查询订单接口查看是否支付成功

• 关键代码

	/*调用微信查询订单接口*/
   			Map<String, String> orderqueryRes = orderquery(wXH5Pay,params.get("out_trade_no"));
   			/*交易成功*/
   			if (!"SUCCESS".equals(orderqueryRes.get("trade_state"))){
   				throw new Exception("<===微信支付失败====>订单号为【"+ params.get("out_trade_no")+ "】的订单");
   			}

   /**
    * 查询支付结果 https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_2
    */
   private static Map<String, String> orderquery(WXPay wxpay, String outTradeNo) throws Exception {
       Map<String, String> parament = new HashMap<String, String>();
   	parament.put("out_trade_no", outTradeNo);
   	return wxpay.orderQuery(parament);
   }