CREATE TABLE product (
  id INT PRIMARY KEY,
  name VARCHAR(100),
  price DECIMAL(10,2),
  stock INT
);
INSERT INTO product (id, name, price, stock) VALUES
  (1, '蘋果13', 10.99, 50),
  (2, '小米10', 19.99, 100),
  (3, '華為mate20', 5.99, 20);

public class Product {
    private Integer id;
    private String name;
    private BigDecimal price;
    private Integer stock;
}

@SpringBootApplication
@MapperScan("com.shoanjen.redis.mapper")
@EnableCaching
@EnableScheduling
@EnableAsync
public class RedisApplication {
	public static void main(String[] args) {
		SpringApplication.run(RedisApplication.class, args);
	}
}

@Component
public class ValidateTask {
    @Autowired
    private ProductMapper productMapper;
    //校驗(yàn)庫(kù)存功能
    @Async
    public Future<Boolean> validateStock(int productId, int quantity){
        //查詢數(shù)據(jù)庫(kù)中的商品
        Product product=productMapper.selectProductById(productId);
        //商品庫(kù)存校驗(yàn)
        if (product==null || product.getStock()<quantity){
            return new AsyncResult<>(false);
        }else {
            //模擬下單操作
            product.setStock(product.getStock()-quantity);
            //這里就演示訂單表保存數(shù)據(jù)了，直接更新庫(kù)存
            productMapper.updateProduct(product);
            return new AsyncResult<>(true);
        }
    }
}

@RestController
@RequestMapping("/api/v1/product")
public class ProductController {
    @Autowired
    private ValidateTask validateTask;
	//productId-商品id，quantity-購(gòu)買數(shù)量
    @RequestMapping("order")
    public JsonData order(@RequestParam int productId,@RequestParam int quantity) throws ExecutionException, InterruptedException {
    	//調(diào)用異步任務(wù)
        Future<Boolean> validateResult=validateTask.validateStock(productId,quantity);
        Boolean flag=false;
        //判斷異步任務(wù)是否完成
        if (validateResult.isDone()){
            try {
                flag=validateResult.get();
            } catch (Exception e) {
                flag=false;
            }
        }
        if (flag){
            return JsonData.buildSuccess("下單成功");
        }else {
            return JsonData.buildError("下單失敗，庫(kù)存不足");
        }
    }

<mapper namespace="com.shoanjen.redis.mapper.ProductMapper">
   <select id="selectProductById" resultType="com.shoanjen.redis.model.Product">
       select * from product where id=#{productId}
   </select>
    <update id="updateProduct" parameterType="com.shoanjen.redis.model.Product">
        update product set name=#{product.name},price=#{product.price},stock=#{product.stock} where id=#{product.id}
    </update>
</mapper>