<!--        aliPay相關(guān)SDK-->
<dependency>
    <groupId>com.alipay.sdk</groupId>
    <artifactId>alipay-sdk-java</artifactId>
    <version>4.17.5.ALL</version>
</dependency>
​
<!--        二維碼生成器-->
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.3.0</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.3.0</version>
</dependency>

import java.io.FileWriter;
import java.io.IOException;
​
public class AlipayConfig {
    
//↓↓↓↓↓↓↓↓↓↓請?jiān)谶@里配置您的基本信息↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
​
    // 應(yīng)用ID,您的APPID，收款賬號既是您的APPID對應(yīng)支付寶賬號
    public static String app_id = "你的APPID";
    
    // 商戶私鑰，您的PKCS8格式RSA2私鑰
    public static String merchant_private_key = "你的私鑰";
    
    // 支付寶公鑰,查看地址：https://openhome.alipay.com/platform/keyManage.htm 對應(yīng)APPID下的支付寶公鑰。
    public static String alipay_public_key="你的應(yīng)用公鑰";
    // 下面是兩個(gè)回調(diào)地址，指支付成功后用戶會(huì)跳轉(zhuǎn)到哪些頁面，不填也可以
    // 服務(wù)器異步通知頁面路徑  需http://格式的完整路徑，不能加?id=123這類自定義參數(shù)，必須外網(wǎng)可以正常訪問
    public static String notify_url = "http://工程公網(wǎng)訪問地址/alipay.trade.page.pay-JAVA-UTF-8/notify_url.jsp";
    // 頁面跳轉(zhuǎn)同步通知頁面路徑 需http://格式的完整路徑，不能加?id=123這類自定義參數(shù)，必須外網(wǎng)可以正常訪問
    public static String return_url = "http://工程公網(wǎng)訪問地址/alipay.trade.page.pay-JAVA-UTF-8/return_url.jsp";
​
    // 簽名方式
    public static String sign_type = "RSA2";
    
    // 字符編碼格式
    public static String charset = "UTF-8";
    
    // 沙箱支付寶網(wǎng)關(guān) 正式支付網(wǎng)關(guān)是 https://openapi.alipay.com/gateway.do 千萬不要混淆了
    public static String gatewayUrl = "https://openapi.alipaydev.com/gateway.do";
    
    // 支付寶網(wǎng)關(guān)
    public static String log_path = "C:\\";
​
    // json格式
    public static String format = "json";
​
​
//↑↑↑↑↑↑↑↑↑↑請?jiān)谶@里配置您的基本信息↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
​
    /** 
     * 寫日志，方便測試（看網(wǎng)站需求，也可以改成把記錄存入數(shù)據(jù)庫）
     * @param sWord 要寫入日志里的文本內(nèi)容
     */
    public static void logResult(String sWord) {
        FileWriter writer = null;
        try {
            writer = new FileWriter(log_path + "alipay_log_" + System.currentTimeMillis()+".txt");
            writer.write(sWord);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}
​

import com.alipay.api.AlipayApiException;
import com.alipay.api.AlipayClient;
import com.alipay.api.DefaultAlipayClient;
import com.alipay.api.request.AlipayTradePagePayRequest;
​
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.data.domain.Pageable;
import lombok.RequiredArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.stereotype.Controller;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import io.swagger.annotations.*;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
​
/**
* @website https://el-admin.vip
* @author nijunwei
* @date 2021-10-18
**/
@Controller
@RequestMapping("/api/test")
public class TestController {
​​   
    @GetMapping("/transcation")
    public   void   doPost (HttpServletRequest httpRequest,
                            HttpServletResponse httpResponse)   throws ServletException, IOException  {
        AlipayClient alipayClient =  new DefaultAlipayClient( AlipayConfig.gatewayUrl , AlipayConfig.app_id, AlipayConfig.merchant_private_key,AlipayConfig.format , AlipayConfig.charset, AlipayConfig.alipay_public_key, AlipayConfig.sign_type);  //獲得初始化的AlipayClient
        AlipayTradePagePayRequest alipayRequest =  new  AlipayTradePagePayRequest(); //創(chuàng)建API對應(yīng)的request
​
        //商戶訂單號，商戶網(wǎng)站訂單系統(tǒng)中唯一訂單號，必填
        String out_trade_no = UUID.randomUUID().toString().substring(0,13);
        //付款金額，必填
        String total_amount = new String("88.88");
        //訂單名稱，必填
        String subject="冬天的第一杯奶茶";
        //商品描述，可空
        String body = new String("我的你的什么？你是我的優(yōu)樂美");
​
        String bizContent="{\"out_trade_no\":\""+ out_trade_no +"\","
                + "\"total_amount\":\""+ total_amount +"\","
                + "\"subject\":\""+ subject +"\","
                + "\"body\":\""+ body +"\","
                + "\"product_code\":\"FAST_INSTANT_TRADE_PAY\"}";
        alipayRequest.setBizContent(bizContent);
  
​
//        alipayRequest.setBizContent(json);
        String form= "" ;
        try  {
            form = alipayClient.pageExecute(alipayRequest).getBody();  //調(diào)用SDK生成表單
        }  catch  (AlipayApiException e) {
            e.printStackTrace();
        }
        // 頁面刷新會(huì)客戶端
        httpResponse.setCharacterEncoding("UTF-8");
        httpResponse.setContentType("text/html;charset=UTF-8");
        httpResponse.getWriter().write(form); //直接將完整的表單html輸出到頁面
        httpResponse.getWriter().flush();
        httpResponse.getWriter().close();
    }
​
}

out_tarde_no:支付單號，用于辨別是否重復(fù)確認(rèn)，支付寶那邊會(huì)有一套機(jī)制防止用戶重復(fù)支付一個(gè)單號的訂單。
total_amount:支付金額，單位為元，可達(dá)到小數(shù)點(diǎn)后兩位，如88.88表示88元8角8分。
subject：支付時(shí)顯示訂單標(biāo)題
body：商品的信息描述
product_code:此處固定為FAST_INSTANT_TRADE_PAY，對于其他代碼的含義可查看官方文檔

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;
​
import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
public class QRCodeGeneratorUtil {
    // 暫定圖片路徑
    private static final String QR_CODE_IMAGE_PATH = "D:\\eladmin\\eladmin\\QRCodePics\\test.png";
​
    private static void generateQRCodeImage(String text, int width, int height, String filePath) throws WriterException, IOException {
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
​
        BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height);
​
        Path path = FileSystems.getDefault().getPath(filePath);
​
        MatrixToImageWriter.writeToPath(bitMatrix, "PNG", path);
​
    }
​
    public static void main(String[] args) {
        try {
            generateQRCodeImage("http://192.168.137.1:8000/api/test/transcation", 350, 350, QR_CODE_IMAGE_PATH);
        } catch (WriterException e) {
            System.out.println("Could not generate QR Code, WriterException :: " + e.getMessage());
        } catch (IOException e) {
            System.out.println("Could not generate QR Code, IOException :: " + e.getMessage());
        }
​
    }
​
}