Java Spring启动验证批注@Valid无效

下面给出的是我的主控制器，我从中调用submitWatchlistItemForm方法

package com.openclassrooms.watchlist;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.view.RedirectView;


@Controller
public class WatchlistController {

    private List<WatchlistItem> watchlistItems = new  ArrayList<WatchlistItem>();
    private static int index = 1;
    
    @PostMapping("/watchlistItemForm")
    public ModelAndView submitWatchlistItemForm(@Valid WatchlistItem watchlistItem, BindingResult bindingResult) {
    
        if(bindingResult.hasErrors()) {
            return new ModelAndView("watchlistItemForm");
        }
        
        WatchlistItem existingItem = findWatchlistItem(watchlistItem.getId());

下面是绑定到命令对象WatchlistItem的my表单

<form action="#" method="post" th:action="@{/watchlistItemForm}" th:object="${watchlistItem}" >
            <h2 class = "mt-4">Submit an item</h2>
            <hr/>
            <!-- Form levels error messages here -->
            <div class = "form-group row ">
               <div class="col-sm-8">
                    <span class="text-danger" > </span>      
                </div>
            </div>
            <div class = "form-group row ">
               <label for = "title" class = "col-sm-2 col-form-label">Title</label>
               <div class = "col-sm-4">
                  <input th:field="*{title}" type = "text" class = "form-control" placeholder = "Mandatory">
               </div>
               <div class="col-sm-4">
                    <span class="text-danger" th:errors="*{title}"> </span>            
                </div>
            </div>
            
            <div class = "form-group row ">
               <label for = "rating" class = "col-sm-2 col-form-label mr-0">Rating</label>
               <div class = "col-sm-4">
                  <input th:field="*{rating}" type = "text" class = "form-control" placeholder = "5.0 < Number < 10.0">
               </div>
               <div class="col-sm-4">
                    <span class="text-danger"> </span>      
                </div>
            </div>
               
            <div class = "form-group row ">
               <label for = "priority" class = "col-sm-2 col-form-label mr-0">Priority</label>
               <div class = "col-sm-4">
                  <input th:field="*{priority}" type = "text" class = "form-control" placeholder = "Low|Medium|High">
               </div>
               <div class="col-sm-4">
                    <span class="error-message" th:errors="*{priority}"></span>      
                </div>
            </div>
               
            <div class = "form-group row">
                <label for = "comments" class = "col-sm-2 col-form-label">Comments</label>
                <div class = "col-sm-4">
                    <textarea th:field="*{comment}" class = "form-control" rows = "3" placeholder = "Max. 50 chars"></textarea>
               </div>
               <div class="col-sm-4">
                    <span class="text-danger" th:errors="*{comment}"> </span>      
                </div>
            </div>
            
            <div class = "form-group row">
               <div class = "col-sm-10">
                  <input th:field="*{id}" type="hidden"></input>
                  <button type = "submit" class = "btn btn-primary">Submit</button>
               </div>            
            </div>
            
         </form>

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。 @有效的注释从不检测错误

但是，验证似乎不起作用，并且没有抛出任何验证错误。控制器bindingResult.hasErrors（）的第27行始终为false。我错过了什么？感谢您的帮助

---

从spring boot 2.3开始，您需要添加spring boot starter验证以使用@Valid

将此依赖项添加到pom.xml

<dependency> 
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring-boot-starter-validation</artifactId> 
</dependency>

---

嘿，你应该读书。不要发布代码的图像。发布实际代码。谢谢@Shawrup。我将依赖项添加到pom.xml中，这是我的工作。

<dependency> 
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring-boot-starter-validation</artifactId> 
</dependency>

public ModelAndView submitWatchlistItemForm(@Valid @RequestBody WatchlistItem watchlistItem, BindingResult bindingResult) {
    ...
}