java.lang.IllegalArgumentException : no product found

Question

嗨，在学习 spring 时，我陷入了以下代码，不确定这段代码有什么问题

@Repositiry

 @Repository
    public class ProductRepositiryImpl implements ProductRepositiry {

        private List<Product> listOfAllProducts = null;

        public ProductRepositiryImpl() {
            listOfAllProducts = new LinkedList<>();

            Product iphone = new Product("A1232", "iPhone", new BigDecimal(500));
            iphone.setDescription("iPhone 6s with 5.2' FHD Screen");
            iphone.setManfactuer("Apple");
            iphone.setCategory("Smart Phone");
            iphone.setUnitsInStock(699);

            listOfAllProducts.add(iphone);
        }

        @Override
        public List<Product> getAllProducts() {
            return listOfAllProducts;
        }

        @Override
        public Product getProductsById(String productId) {
            Product productById = null;
            for (Product product : listOfAllProducts) {
                if (product != null && product.getProductId() != null && product.getProductId().equals(productId)) {
                    productById = product;
                    break;
                }

                if (productById == null)
                    throw new IllegalArgumentException("no product found " + productId);

            }
            return productById;

        }

    }


**Service**



@Service
public class ProductServiceImpl implements ProductService {

    @Autowired
ProductRepositiry productRepositiry;

@Override
public void processOrder(String productId, long count) {
    System.out.println("inside Process Order");

    Product getProductByid = productRepositiry.getProductsById(productId);
    System.out.println("get product by id");
    System.out.println(getProductByid);
    if (getProductByid.getUintsInOrder() < getProductByid.getUnitsInStock()) {
        throw new IllegalArgumentException("OUT OF STOCK" + getProductByid.getUintsInOrder());
    } 
        getProductByid.setUintsInOrder(getProductByid.getUintsInOrder() - count);
}
**@controller**



@Controller
public class OrderController {

    @Autowired
    OrderService orderService;

    @RequestMapping("/order/A1234/2")
    public String processOrder() {
        System.out.println("process order");
        orderService.processOrder("A1232", 2);
        return "redirect:/product";
    }
}

StackTrack

SEVERE: Servlet.service() for servlet [dispatcherServlet] in context with path [/web_Store] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: no product found A1233] with root cause java.lang.IllegalArgumentException: no product found A1233 at com.webstore.repoImpl.ProductRepositiryImpl.getProductsById(ProductRepositiryImpl.java:58) at com.webstore.serviceImpl.OrderServiceImpl.processOrder(OrderServiceImpl.java:20) at com.webstore.controller.OrderController.processOrder(OrderController.java:18) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source)

在类 ProductRepositiryImpl 中，每当我尝试执行方法 getProductsById(String ProductId) 并且在调试时，我都会得到 productById = Product; 持有有效值，那么它应该退出循环为什么它仍然收到 IllegalArgumentException任何帮助将不胜感激

最诚挚的问候

Answer 1

public ProductRepositiryImpl() {
            listOfAllProducts = new LinkedList<>();

            Product iphone = new Product("A1232", "iPhone", new BigDecimal(500));
            iphone.setDescription("iPhone 6s with 5.2' FHD Screen");
            iphone.setManfactuer("Apple");
            iphone.setCategory("Smart Phone");
            iphone.setUnitsInStock(699);

            listOfAllProducts.add(iphone);
    }

您正在添加ID A1232的产品

@RequestMapping("/order/A1234/2")
    public String processOrder() {
        System.out.println("process order");
        orderService.processOrder("A1233", 2);
        return "redirect:/product";
    }

您正在尝试获取ID A1233的产品

编辑1:

如@Florian在上面的评论中说道。将 productById == null 的检查移到 for 循环之外

public Product getProductsById(String productId) {
            Product productById = null;
            for (Product product : listOfAllProducts) {
                if (product != null && product.getProductId() != null && product.getProductId().equals(productId)) {
                    productById = product;
                    break;
                }              
            }
            if (productById == null)
                    throw new IllegalArgumentException("no product found " + productId);

           return productById;

}