SpringBoot:MissingServletRequestParameterException:Erforderlicher Anforderungsparameter „itemId“ für den Methodenparamet ⇐ Java

[Anonymous]

Ich versuche, eine Anwendung in Spring Boot zu erstellen. Ich definiere die Methoden „updateBasket“ und „removeItem“, aber sie scheinen Probleme zu haben. Als ich das Projekt ausführte und im Formular auf „Menge aktualisieren“ klickte, wurde mir ein Whitelabel-Fehler mit der Meldung „Ungültiger Anforderungstyp, Status 400“ angezeigt. In den Tomcat-Serverprotokollen wird Folgendes angezeigt:
„Behoben [org.springframework.web.bind.MissingServletRequestParameterException: Erforderlicher Anforderungsparameter ‚itemId‘ für den Methodenparametertyp Long ist vorhanden, aber in Null konvertiert]“
package com.example.test1.controller;

import com.example.test1.model.Beverage;
import com.example.test1.model.OrderItem;
import com.example.test1.model.Order;
import com.example.test1.service.BeverageService;
import com.example.test1.service.OrderItemService;
import com.example.test1.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import jakarta.servlet.http.HttpServletRequest;
// Import the HttpServletRequest

import java.text.DecimalFormat;

import jakarta.servlet.http.HttpSession;
import java.util.List;
import java.util.ArrayList;

@Controller
public class BasketController {

@Autowired
private BeverageService beverageService;

@Autowired
private OrderItemService orderItemService;

@Autowired
private OrderService orderService;

@GetMapping("/basket")
public String showBasket(HttpSession session, Model model) {
// Retrieve the basket from the session
List basket = (List) session.getAttribute("basket");

// If the basket is null (i.e., no items in the basket), initialize it
if (basket == null) {
basket = new ArrayList();
}

// Calculate the total price
double totalPrice = 0;
for (OrderItem item : basket) {
totalPrice += item.getPrice();
}

// Add the basket and the total price to the model so it can be accessed in the Thymeleaf template
model.addAttribute("items", basket);
model.addAttribute("totalPrice", totalPrice);

// Return the name of the Thymeleaf template to render
return "basket"; // This refers to the "basket.html" template
}

// Add beverage to basket
// BasketController.java
@PostMapping("/add-to-basket")
public String addToBasket(@RequestParam Long beverageId, HttpSession session) {
Beverage beverage = beverageService.getBeverageById(beverageId);

OrderItem orderItem = new OrderItem();
orderItem.setBeverage(beverage);
orderItem.setPrice(beverage.getPrice());

// Retrieve the current basket from the session or create a new one
List basket = (List) session.getAttribute("basket");
if (basket == null) {
basket = new ArrayList();
}

// Add the new OrderItem to the basket
basket.add(orderItem);

// Save the updated basket back into the session
session.setAttribute("basket", basket);

return "redirect:/basket"; // Redirect to the basket page to view the updated contents
}

@PostMapping("/submit-order")
public String submitOrder(HttpSession session, Model model) {
List basket = (List) session.getAttribute("basket");

if (basket != null && !basket.isEmpty()) {
// Create a new Order and set total price, etc.
Order order = new Order();
double totalPrice = 0;
for (OrderItem item : basket) {
totalPrice += item.getPrice(); // Calculate total price for the basket
}
order.setPrice(totalPrice); // Set the price of the order

// Save the order
orderService.saveOrder(order);

// Associate OrderItems with the Order
for (OrderItem item : basket) {
item.setOrder(order); // Link each item to the order
orderItemService.saveOrderItem(item); // Save the OrderItem
}

// Remove the basket from the session
session.removeAttribute("basket");

// Add order details to the model for the confirmation page
model.addAttribute("totalPrice", totalPrice); // Pass total price to the view
model.addAttribute("orderItems", basket); // Pass order items to the view
}

return "order-confirmation"; // Redirect to the order confirmation page
}

@PostMapping("/update-basket")
public String updateBasket(@RequestParam Long itemId, @RequestParam int quantity, HttpSession session, HttpServletRequest request) {
// Debugging: Print received itemId and quantity
System.out.println("Received itemId: " + itemId + ", quantity: " + quantity);

// Invalidate the current session and create a new one to avoid any session inconsistencies
session.invalidate(); // Clears the current session
session = request.getSession(true); // Creates a new session

// Retrieve the basket from session
List basket = (List) session.getAttribute("basket");

if (basket != null && !basket.isEmpty()) {
// Look for the OrderItem by id
for (OrderItem item : basket) {
System.out.println("Checking item with ID: " + item.getId());

if (item.getId() != null && item.getId().equals(itemId)) {
// Found the correct item, update its quantity and price
item.setQuantity(quantity);
item.setPrice(item.getBeverage().getPrice() * quantity);

// Debugging: print updated item details
System.out.println("Updated item: " + item.getId() + ", Quantity: " + item.getQuantity() + ", Price: " + item.getPrice());
break;
}
}

// Save the updated basket back into the session
session.setAttribute("basket", basket);
}

// Redirect back to the basket page to reflect the changes
return "redirect:/basket";
}

@PostMapping("/remove-item")
public String removeItem(@RequestParam Long itemId, HttpSession session) {
List basket = (List) session.getAttribute("basket");
if (basket != null) {
basket.removeIf(item -> item.getId().equals(itemId)); // Remove item by itemId
session.setAttribute("basket", basket); // Save updated basket in session
}
return "redirect:/basket"; // Redirect back to basket page
}
}

Dies ist die BasketController.java-Datei, in der ich die Logik definiere.
basket.html:




Your Basket


Your Basket



Your basket is empty. Add some beverages to your basket first.


<


Basket.html Form
Ensure your form is correctly structured. Specifically, ensure that the input fields for itemId and quantity are correctly named and bound:

html
Copy code




Quantity

Update Quantity





Remove






Place Order





und die Modellklasse OrderItem.java:
package com.example.test1.model;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.ManyToOne;
import jakarta.persistence.JoinColumn;

@Entity
public class OrderItem {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

private String position;

private double price;

private int quantity = 1; // Default quantity

@ManyToOne
@JoinColumn(name = "beverage_id")
private Beverage beverage; // This is the reference to the Beverage entity

@ManyToOne
@JoinColumn(name = "order_id")
private Order order; // The order to which this item belongs

// Getters and Setters

public int getQuantity() {
return quantity;
}

public void setQuantity(int quantity) {
this.quantity = quantity;
}

public Long getId() {
return id;
}

public void setId(Long id) {
this.id = id;
}

public String getPosition() {
return position;
}

public void setPosition(String position) {
this.position = position;
}

public double getPrice() {
return price * quantity; // Return price based on quantity
}

public void setPrice(double price) {
this.price = price;
}

public Beverage getBeverage() {
return beverage;
}

public void setBeverage(Beverage beverage) {
this.beverage = beverage;
}

public Order getOrder() {
return order;
}

public void setOrder(Order order) {
this.order = order; // Set the order for the order item
}
}

Es gibt auch einige andere Modellklassen und Controller in meinem Projekt, aber ich denke, dass diese zum Verständnis des Problems ausreichen sollten. Warum wird die ID als Null zurückgegeben?