Java 弹簧靴&x2B；事件应用程序中的休眠控制器

我想创建一个事件应用程序，用户可以使用它添加事件，然后添加注释。我的注释控制器有问题。我希望将注释添加到comments and events表中，并且注释与事件相关

我应该如何修改控制器

@Controller
@RequestMapping("/comments")
public class CommentController {
    @Autowired
    private CommentService commentService;
    @Autowired
    private EventService eventService;
    @GetMapping("/newComment")
    public String newComment(Model model) {

        Comment comment = new Comment();
        model.addAttribute("comment", comment);
        return "redirect:/list";
    }

    @PostMapping("/saveComment/{id}")
    public String createComment( @PathVariable long id, @ModelAttribute Comment comment) {
        // save comment to database
        model.addAttribute("event", event);
        commentService.saveComment(comment);
        List comments = new ArrayList();
        comments.add(commentService.createComment(comment));
        event.setComments(comments);
        return "redirect:/list";
    }

事件控制器：

@Controller
public class EventController {

    @Autowired
    private EventService eventService;

    // display list of events
    @GetMapping("/list")
    public String viewHomePage(Model model) {
        model.addAttribute("listEvents", eventService.getAllEvents());
        return "list";
    }

    @GetMapping("/showNewEventForm")
    public String showNewEventForm(Model model) {
        // create model attribute to bind form data
        Event event = new Event();
        model.addAttribute("event", event);
        return "new_event";
    }

    @PostMapping("/saveEvent")
    public String saveEvent(@ModelAttribute("event") Event event) {
        // save event to database
        eventService.saveEvent(event);
        return "redirect:/list";
    }

    @GetMapping("/showFormForUpdate/{id}")
    public String showFormForUpdate(@PathVariable( value = "id") long id, Model model) {

        // get event from the service
        Event event = eventService.getEventById(id);

        // set event as a model attribute to pre-populate the form
        model.addAttribute("event", event);
        return "update_event";
    }

    @GetMapping("/deleteEvent/{id}")
    public String deleteEvent(@PathVariable (value = "id") long id) {

        // call delete event method
        this.eventService.deleteEventById(id);
        return "redirect:/list";
    }

    @GetMapping("/showDescription/{id}")
    public String showDescription(@PathVariable( value = "id") long id, Model model, Model model2) {
        // get event from the service
        Event event = eventService.getEventById(id);
        Comment comment = new Comment();
        // set event as a model attribute to pre-populate the form
        model.addAttribute("event", event);
        model2.addAttribute("comment", comment);
        return "description";
    }
    }

注释实体：

@Entity
@Table(name = "comments")
public class Comment {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    @Column(name = "text")
    private String text;
    @Column(name = "rating")
    private int rating;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "eve_com")
    private Event event;
 
    public Comment() {
    }

  
    public long getId() {return id;}
    public void setId(long id) {this.id = id;}
    public String getText() {return text; }
    public void setText(String text) {this.text = text;}
    public int getRating() {return rating; }
    public void setRating(int rating) {this.rating = rating;}
    public Event getEvent() {
        return event;
    }

    public void setEvent(Event event) {
        this.event = event;
    }

}

评论服务：

@Service
public class CommentServiceImpl implements CommentService {

    @Autowired
    private CommentRepository commentRepository;

    @Override
    public List<Comment> getAllComment() {
        return commentRepository.findAll();
    }

    @Override
    public Object createComment(Comment comment) {
        this.commentRepository.save(comment);
        return null;
    }
}

@Service
public class EventServiceImpl implements EventService {

    @Autowired
    private EventRepository eventRepository;

    @Override
    public List <Event> getAllEvents() {
        return eventRepository.findAll();
    }

    @Override
    public void saveEvent(Event event) {
        this.eventRepository.save(event);
    }

    @Override
    @PutMapping
    public Event getEventById(long id) {
        Optional < Event > optional = eventRepository.findById(id);
        Event event = null;
        if (optional.isPresent()) {
            event = optional.get();
        } else {
            throw new RuntimeException("Event not found for id ::" + id);
        }
        return event;
    }

    @Override
    public void deleteEventById(long id) {
        this.eventRepository.deleteById(id);
    }
}

@服务
公共类CommentServiceImpl实现CommentService{
@自动连线
私有评论库；
@凌驾
公共列表getAllComment（）{
返回commentRepository.findAll（）；
}
@凌驾
公共对象createComment（Comment）{
this.commentRepository.save（comment）；
返回null；
}
}

事件实体：

@Entity
@Table(name = "events")
public class Event {

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

    @Column(name = "name")
    private String name;

    @Column(name = "city")
    private String city;

    @Column(name = "date")
    private String date;

    @Column(name = "description")
    private String description;

    // one to many relationship with messages
    @OneToMany(cascade = CascadeType.ALL)
    List<Comment> comments = new ArrayList<>();
    
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() { return name;}
    public void setName(String name) {
        this.name = name;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getDate() {
        return date;
    }
    public void setDate(String date) {
        this.date = date;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public List<Comment> getComments() { return comments;}
    public void setComments(List<Comment> comments) {this.comments = comments;}
}

@实体
@表（name=“events”）
公开课活动{
@身份证
@GeneratedValue（策略=GenerationType.IDENTITY）
私人长id；
@列（name=“name”）
私有字符串名称；
@列（name=“city”）
私人城市；
@列（name=“date”）
私有字符串日期；
@列（name=“description”）
私有字符串描述；
//与消息的一对多关系
@OneToMany（级联=级联类型.ALL）
列表注释=新建ArrayList（）；
公共长getId（）{
返回id；
}
公共无效集合id（长id）{
this.id=id；
}
公共字符串getName（）{return name；}
公共void集合名（字符串名）{
this.name=名称；
}
公共字符串getCity（）{
回归城市；
}
公共城市（字符串城市）{
this.city=城市；
}
公共字符串getDate（）{
返回日期；
}
公共无效设置日期（字符串日期）{
this.date=日期；
}
公共字符串getDescription（）{
返回说明；
}
公共void集合描述（字符串描述）{
this.description=描述；
}
public List getComments（）{return comments；}
public void setComments（列出注释）{this.comments=comments；}
}

活动及服务：

@Service
public class CommentServiceImpl implements CommentService {

    @Autowired
    private CommentRepository commentRepository;

    @Override
    public List<Comment> getAllComment() {
        return commentRepository.findAll();
    }

    @Override
    public Object createComment(Comment comment) {
        this.commentRepository.save(comment);
        return null;
    }
}

@Service
public class EventServiceImpl implements EventService {

    @Autowired
    private EventRepository eventRepository;

    @Override
    public List <Event> getAllEvents() {
        return eventRepository.findAll();
    }

    @Override
    public void saveEvent(Event event) {
        this.eventRepository.save(event);
    }

    @Override
    @PutMapping
    public Event getEventById(long id) {
        Optional < Event > optional = eventRepository.findById(id);
        Event event = null;
        if (optional.isPresent()) {
            event = optional.get();
        } else {
            throw new RuntimeException("Event not found for id ::" + id);
        }
        return event;
    }

    @Override
    public void deleteEventById(long id) {
        this.eventRepository.deleteById(id);
    }
}

@服务
公共类EventServiceImpl实现EventService{
@自动连线
私有事件存储库事件存储库；
@凌驾
公共列表getAllEvents（）{
返回eventRepository.findAll（）；
}
@凌驾
公共作废保存事件（事件）{
this.eventRepository.save（事件）；
}
@凌驾
@PutMapping
公共事件getEventById（长id）{
可选Optional=eventRepository.findById（id）；
事件=null；
if（可选的.isPresent（））{
event=optional.get（）；
}否则{
抛出新的RuntimeException（“未找到id:：“+id的事件”）；
}
返回事件；
}
@凌驾
public void deleteEventById（长id）{
this.eventRepository.deleteById（id）；
}
}
尝试在链接事件实体和注释实体时考虑@ MyTyOne注释。试着用谷歌搜索一下。然后，您可以保存特定事件的注释。