支付宝小程序（支付）

1.首先要注册企业账号，并创建小程序，在支付宝开发工具中与项目做关联

2.配置环境https://docs.alipay.com/mini/introduce/pay根据步骤做小程序开发准备并签约小程序支付。

下面配置是小程序的信息，可根据https://blog.csdn.net/wwt1996/article/details/86065209对密钥进行配置，AES可以不设置

3.根据小程序授权的授权码获取buyer_id即返回的userId

package cn.icr.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.alipay.api.request.AlipaySystemOauthTokenRequest;
import com.alipay.api.request.AlipayTradeCreateRequest;
import com.alipay.api.response.AlipaySystemOauthTokenResponse;
import com.alipay.api.response.AlipayTradeCreateResponse;

import cn.icr.util.AlipayConfigApp;
import cn.icr.util.GenerateOrderNoUtil;

@RestController
@RequestMapping("/order")
public class PayController2 {
	private   GenerateOrderNoUtil  gu=new  GenerateOrderNoUtil();
	@RequestMapping("/getuserid")
	public   String   returncode(@RequestParam(value="token")String token){
	//向支付宝发送请求
    //获得初始化的AlipayClient
	//获得初始化的AlipayClient
    AlipayClient alipayClient = new DefaultAlipayClient(AlipayConfigApp.gatewayUrl, AlipayConfigApp.app_id, AlipayConfigApp.merchant_private_key, "json", AlipayConfigApp.charset, AlipayConfigApp.alipay_public_key, AlipayConfigApp.sign_type);
	AlipaySystemOauthTokenRequest request = new AlipaySystemOauthTokenRequest();
	request.setCode(token);//这个就是第一步获取的auth_code
	request.setGrantType("authorization_code");//这个固定值,参考https://docs.open.alipay.com/api_9/alipay.system.oauth.token
	try {
	    AlipaySystemOauthTokenResponse oauthTokenResponse = alipayClient.execute(request);
	    System.out.println(oauthTokenResponse.getBody());
	    System.out.println(oauthTokenResponse.getUserId());
	    return oauthTokenResponse.getUserId();
	} catch (AlipayApiException e) {
	    //处理异常
	    e.printStackTrace();
	}
	return "";

	}
	@RequestMapping("/pay")
	public   String   topay(@RequestParam(value="pid")String pid){
		String  out_trade_no=gu.gen("R",530L);
		System.out.println("买家账号"+pid);
		//实例化客户端
		 AlipayClient alipayClient = new DefaultAlipayClient(AlipayConfigApp.gatewayUrl, AlipayConfigApp.app_id, AlipayConfigApp.merchant_private_key, "json", AlipayConfigApp.charset, AlipayConfigApp.alipay_public_key, AlipayConfigApp.sign_type);
		//实例化具体API对应的request类,类名称和接口名称对应,当前调用接口名称：alipay.trade.create.
		AlipayTradeCreateRequest request = new AlipayTradeCreateRequest();
		//SDK已经封装掉了公共参数，这里只需要传入业务参数。
		request.setBizContent("{" +
				"\"out_trade_no\":\""+out_trade_no+"\"," +
				"\"total_amount\":0.01," +
				"\"subject\":\"买东西\"," +
				"\"buyer_id\":\""+pid+"\"" +
				"}");
		try {
		    //使用的是execute
		    AlipayTradeCreateResponse response = alipayClient.execute(request);
		    String trade_no = response.getTradeNo();//获取返回的tradeNO。
		    System.out.println("生成的单号"+trade_no);
		    return trade_no;
		} catch (AlipayApiException e) {
		    e.printStackTrace();
		}
		return "";

	}
}

4.开始前端处理唤起支付

//小程序中传入唤醒支付
 my.tradePay({
		tradeNO: '传入返回的trade_no',  
		success: function(res) {
			my.alert(res.resultCode);
		},
		fail: function(res) {
          my.alert(res.resultCode);
       },
	});