Java Spring@Autowired服务奇怪地为空，尽管它在所有地方都使用了必填字段

我正在使用pojo处理表单请求，并尝试使用Autowired访问服务。但不管我试图改变什么，它总是返回null。我会发布我所有的代码，请看一下

类别及格式：

在这个页面中，我尝试使用categoryService，但它似乎是空的（null），当我尝试使用服务中的任何函数时，我得到了nullpointerexception。我没有尝试在任何地方初始化autowired类

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@Component
public class CategoryAddForm {
    private Long id;
    private String title;
    private String description;
    private String language;
    private String image_url;

    @Autowired
    CategoryService categoryService;

    public Category save() {
        Category category;
        if(this.id==null) {
            if(this.language==null || this.language.trim().equals("en")) {
                category = Category.builder()
                        .title_en(this.title)
                        .description_en(this.description)
                        .image_url(this.image_url)
                        .en_available(true)
                        .count(0l).build();
                System.out.println("New for English: \n id: "+this.id+" \n title:"+this.title+"\n description: "+this.description+"\n language: "+this.language);
                System.out.println(categoryService);
//                categoryService.save(category);
            }
            else {
                category = Category.builder()
                        .title_np(this.title)
                        .description_np(this.description)
                        .np_available(true)
                        .en_available(false)
                        .count(0l).build();
                System.out.println("New for Nepali: \n id: "+this.id+" \n title:"+this.title+"\n description: "+this.description+"\n language: "+this.language);
                System.out.println(categoryService);
//                categoryService.save(category);
            }
        }
        else {
            if(this.language==null || this.language.trim().equals("en")) {
                category = Category.builder()
                        .id(this.id)
                        .title_en(this.title)
                        .description_en(this.description)
                        .en_available(true)
                        .image_url(this.image_url).build();
            }
            else {
                category = Category.builder()
                        .id(this.id)
                        .title_np(this.title)
                        .description_np(this.description)
                        .np_available(true)
                        .image_url(this.image_url).build();
            }
        }
        System.out.println(category);
    return categoryService.save(category);

    }
}

表格页：

此页面将categoryForm对象发送到/保存在控制器中，该控制器调用CategoryAddForm中的save函数

            <form th:action="@{'/admin/category/save'}" method="post" th:object="${categoryForm}">
                <div class="form-group my-1 p-2 row">
                    <label for="categoryTitle">Title</label>
                    <input type="title" class="form-control" name="title" id="categoryTitle" th:field="*{title}">
                </div>
                <div class="form-group my-1 p-2 row">
                    <label for="categoryDescription">Description</label>
                    <textarea rows="5" type="description" class="form-control" name="description" id="categoryDescription" th:field="*{description}">
                    </textarea>
                </div>
                <div class="form-check my-1 p-2 row">
                    <label for="languages">Select Language</label>
                    <div id="languages" class="row ml-2">

                        <div class="col-2" >
                            <input class="form-check-input" type="radio" value="en" th:field="*{language}" id="englishLanguage" th:selected="selected">
                            <label class="form-check-label" for="englishLanguage">
                                English
                            </label>
                        </div>
                        <div class="col-2" >
                            <input class="form-check-input" type="radio" value="ne" th:field="*{language}" id="nepaliLanguage">
                            <label class="form-check-label" for="nepaliLanguage">
                                Nepali
                            </label>
                        </div>
                    </div>
                </div>
                <button type="submit" class="btn btn-primary m-2">Submit</button>
            </form>

---

问题是，每次进行reuqest时，您都在创建一个新的CategoryAddForm，并且您没有让spring管理您的bean。如果您正在创建CategradForm的新实例，spring将不知道需要将您的服务注入其中。我认为您可以尝试通过构造函数进行注入。

您在项目中定义了CategoryRepository吗？请共享项目生成堆栈跟踪。

@Service
public class CategoryServiceImpl implements CategoryService {
    @Autowired
    private CategoryRepository repository;
    @Override
    public Category save(Category document) {
        return repository.save(document);
    }

    @Override
    public Category getById(Long id) {
        return repository.getOne(id);
    }

    @Override
    public void delete(Category document) {
        repository.delete(document);
    }

    @Override
    public void deleteById(Long id) {
        repository.deleteById(id);
    }

    @Override
    public List<Category> getAllCategories() {
        return repository.findAll();
    }
}

@PostMapping(value = "/save")
public ModelAndView submitCategory(@ModelAttribute("categoryForm") CategoryAddForm categoryForm, BindingResult result){
    categoryForm.save();
    if(result.hasErrors()){
        return new ModelAndView("redirect:/admin/category/add?error");
    }
    return new ModelAndView("redirect:/admin/category/add");
}