<!-- pom.xml -->
<dependencies>
    <!-- Spring Boot Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <!-- MyBatis & MySQL -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.2.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    
    <!-- 支付寶SDK -->
    <dependency>
        <groupId>com.alipay.sdk</groupId>
        <artifactId>alipay-sdk-java</artifactId>
        <version>4.35.0.ALL</version>
    </dependency>
    
    <!-- Lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
</dependencies>

@Configuration
public class AlipayConfig {

    @Value("${alipay.app_id}")
    private String appId;
    
    @Value("${alipay.merchant_private_key}")
    private String merchantPrivateKey;
    
    @Value("${alipay.alipay_public_key}")
    private String alipayPublicKey;
    
    @Value("${alipay.notify_url}")
    private String notifyUrl;
    
    @Value("${alipay.return_url}")
    private String returnUrl;
    
    @Value("${alipay.gateway_url}")
    private String gatewayUrl;
    
    @Value("${alipay.sign_type}")
    private String signType;
    
    @Value("${alipay.charset}")
    private String charset;

    @Bean
    public AlipayClient alipayClient() {
        return new DefaultAlipayClient(
            gatewayUrl,
            appId,
            merchantPrivateKey,
            "json",
            charset,
            alipayPublicKey,
            signType
        );
    }
}

// 訂單實體
@Data
public class Order {
    private Long id;
    private String orderNo;   // 商戶訂單號
    private BigDecimal amount;// 支付金額
    private Integer status;   // 0-待支付, 1-已支付
    private LocalDateTime createTime;
}

// MyBatis Mapper
@Mapper
public interface OrderMapper {
    @Insert("INSERT INTO orders(order_no, amount, status, create_time) " +
            "VALUES(#{orderNo}, #{amount}, 0, NOW())")
    @Options(useGeneratedKeys = true, keyProperty = "id")
    void insert(Order order);
    
    @Update("UPDATE orders SET status = #{status} WHERE order_no = #{orderNo}")
    void updateStatus(@Param("orderNo") String orderNo, @Param("status") int status);
}

@Service
public class PayService {

    @Autowired private AlipayClient alipayClient;
    @Autowired private OrderMapper orderMapper;
    @Value("${alipay.return_url}") private String returnUrl;
    @Value("${alipay.notify_url}") private String notifyUrl;

    // 創(chuàng)建支付訂單
    public String createPayOrder(Order order) throws AlipayApiException {
        orderMapper.insert(order); // 保存訂單到數(shù)據(jù)庫
        
        AlipayTradePagePayRequest request = new AlipayTradePagePayRequest();
        request.setReturnUrl(returnUrl);
        request.setNotifyUrl(notifyUrl);
        
        // 構造業(yè)務參數(shù)
        JSONObject bizContent = new JSONObject();
        bizContent.put("out_trade_no", order.getOrderNo());
        bizContent.put("total_amount", order.getAmount());
        bizContent.put("subject", "商品支付");
        bizContent.put("product_code", "FAST_INSTANT_TRADE_PAY"); // 電腦網站支付
        
        request.setBizContent(bizContent.toString());
        
        return alipayClient.pageExecute(request).getBody();
    }

    // 處理異步通知
    public boolean handleNotify(Map<String, String> params) throws AlipayApiException {
        // 1. 驗證簽名
        boolean signVerified = AlipaySignature.rsaCheckV1(
                params,
                alipayPublicKey,  // 注入支付寶公鑰
                charset,
                signType
        );
        
        if (!signVerified) return false;

        // 2. 驗證交易狀態(tài)
        String tradeStatus = params.get("trade_status");
        if (!"TRADE_SUCCESS".equals(tradeStatus)) return false;

        // 3. 更新訂單狀態(tài)
        String orderNo = params.get("out_trade_no");
        orderMapper.updateStatus(orderNo, 1); // 更新為已支付
        
        return true;
    }
}

@RestController
@RequestMapping("/pay")
public class PayController {

    @Autowired private PayService payService;

    // 創(chuàng)建支付訂單
    @PostMapping("/create")
    public String createOrder(@RequestParam BigDecimal amount) 
        throws AlipayApiException {
        
        Order order = new Order();
        order.setOrderNo(UUID.randomUUID().toString().replace("-", ""));
        order.setAmount(amount);
        
        return payService.createPayOrder(order); // 返回支付頁面表單
    }

    // 支付寶異步通知（需公網可訪問）
    @PostMapping("/notify")
    public String alipayNotify(HttpServletRequest request) 
        throws UnsupportedEncodingException, AlipayApiException {
        
        Map<String, String> params = parseRequestParams(request);
        boolean success = payService.handleNotify(params);
        return success ? "success" : "failure"; // 通知支付寶處理結果
    }

    // 支付寶同步跳轉
    @GetMapping("/return")
    public String alipayReturn(HttpServletRequest request) {
        // 簡單展示支付結果（實際需要驗簽和狀態(tài)檢查）
        return "支付完成！訂單號：" + request.getParameter("out_trade_no");
    }

    // 解析請求參數(shù)
    private Map<String, String> parseRequestParams(HttpServletRequest request) {
        // 轉換參數(shù)Map（參考支付寶示例代碼）
    }
}

# application.properties
# 支付寶配置
alipay.app_id=2021000123456789
alipay.merchant_private_key=MIIEvQIBADANB...
alipay.alipay_public_key=MIIBIjANBgkq...
alipay.notify_url=http://your-domain.com/pay/notify
alipay.return_url=http://your-domain.com/pay/return
alipay.gateway_url=https://openapi.alipay.com/gateway.do
alipay.sign_type=RSA2
alipay.charset=UTF-8

# MySQL配置
spring.datasource.url=jdbc:mysql://localhost:3306/alipay_demo
spring.datasource.username=root
spring.datasource.password=123456