Question

我需要帮助我的多对多映射，我想通过表单将项目列表添加到类中。我正在制作电影和演员的数据库，以及电影＆＃39;电影＆＃39; class I有一个包含该电影中的actor的列表，该列表被映射到＆＃39; Actor＆＃39;类。

这是为了添加电影：

<body>
Add Movie
<form:form modelAttribute="movie">
Title:
<form:input path="title" /><br />
Rating:
<form:input path="rating" /><br />
Year:
<form:input path="year" /><br />

<form:select path="actors">
    <c:forEach items="${actor}" var="p">
        <form:option value="${???}">${p.name}</form:option>
    </c:forEach>
</form:select>

<input type="submit" value="Save movie" />

首先我输入新电影的值（标题，评级和发布的年份），然后我有一个选择表格，列出一组演员，想法是选择电影中的演员，但我不知道该怎么做。

控制器：

    @RequestMapping(value="/add", method = RequestMethod.GET)
public Movie showMAddForm(Model model){
    List<Actor> actor = actorService.list();
    model.addAttribute("actor", actor);
    return new Movie();
}

@RequestMapping(value="/add", method = RequestMethod.POST)
public String saveMAddForm(Movie m){
    movieService.saveMovie(m);
    return "saved";
}

我需要做什么才能在新制作的电影中选择我想要的演员？

编辑：这是我的演员类

@Entity
@Table
public class Actor {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column
private int actor_id;
private String name;
private String age;
private String link;

private List<Movie> movies = new ArrayList<Movie>();

// Setters and Getters

@ManyToMany(fetch = FetchType.EAGER, mappedBy = "actors")
public List<Movie> getMovies(){
    return this.movies;
}

public void setMovies(List<Movie> movies){
    this.movies = movies;
}

}

这是Movie类，所以你可以看到映射是如何

@Entity
@Table
public class Movie {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column
private int movie_id;
private String title;
private String rating;
private String year;

private List<Actor> actors = new ArrayList<Actor>();

// Setters and getters

@ManyToMany(fetch = FetchType.EAGER, targetEntity = com.springapp.mvc.Actor.class)
@JoinTable(name= "ActorList", joinColumns = {@JoinColumn(name="actor_id")},
        inverseJoinColumns= {@JoinColumn(name="movie_id")})
public List<Actor> getActors(){
    return this.actors;
}
public void setActors(List<Actor> actors){
    this.actors = actors;
}

}

Answer 1

我不知道你是否确实需要这个，但我正在尝试，所以如果有任何问题，请告诉我，我会根据你的要求进行编辑：

person model class：Person.java

@Entity
@Table(name="person")
public class Person implements UserDetails{

 @Id
    @Column(name="id")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "person_seq_gen")
    @SequenceGenerator(name = "person_seq_gen",sequenceName = "person_seq")
    private int id;

    @Valid
    @NotEmpty @Email(message = "email.empty")
    @Column(name = "username")
    private String username;

    @Valid
    @Size(min = 6)
    @NotEmpty(message = "Password may not be empty")
    @Column(name = "password")
    private String password;

  @OneToMany(mappedBy = "person1",fetch = FetchType.EAGER)
    private Set<Canvas> canvas1 = new HashSet<Canvas>();

    public Set<Canvas> getCanvas1() {
        return canvas1;
    }

    public void setCanvas1(Set<Canvas> canvas1) {

        this.canvas1 = canvas1;
    }
}

@Entity
@Table(name = "canvas")
public class Canvas {

    @Id
    @Column(name="canvasid")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "canvas_gen")
    @SequenceGenerator(name = "canvas_gen",sequenceName = "canvas_seq")
    private int canvasid;

    @Column(name = "canvasname")
    private String canvasname;
 @ManyToOne
    @JoinColumn(name = "id",nullable = false)
    private Person person1;

    public Person getPerson1() {
        return person1;
    }

    public void setPerson1(Person person1) {
        this.person1 = person1;
    }

    public int getPerson1id(){
        return this.person1.getId();
    }
}

PersonDAOImpl：此类将人员保存在数据库中：

@Transactional
@Repository
public class PersonDAOImpl implements PersonDAO{

    private SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory sf){
        this.sessionFactory = sf;
    }

    private Session session;

    public void setSession(Session session){this.session = session;}


    @Override
    @Transactional
    public void addPerson(Person p) {

        if( session == null) {
            session = this.sessionFactory.openSession();
        }else {
            session = this.sessionFactory.getCurrentSession();
        }
        session.saveOrUpdate(p);

    }
}

CanvasDAOImpl：此类保存画布

@Transactional
@Repository
public class CanvasDAOImpl implements CanvasDAO{

    private SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory sf){
        this.sessionFactory = sf;
    }

    private Session session;

    public void setSession(Session session){this.session = session;}

    @PreAuthorize("hasRole('ROLE_USER')")
    @Override
    public void addCanvas(Canvas canvas, Person person) {
        int id = person.getId();
        if( session == null) {
            session = this.sessionFactory.openSession();
        }else {
            session = this.sessionFactory.getCurrentSession();
        }
        Person person1 = (Person) session.get(Person.class,id);
        person.getCanvas1().add(canvas);
        canvas.setPerson1(person1);
       session.merge(canvas);

        session.flush();
    }
}

控制器方法：

@RequestMapping(value= "/person/add", method = RequestMethod.POST)
    public String addPerson(@Valid Person person,BindingResult bindingResult,@ModelAttribute("person") Person p,Model model){
        if(bindingResult.hasErrors()){

            model.addAttribute("errors",bindingResult.getAllErrors());
            return "redirect:/";
        }

            this.personService.addPerson(p);
            return "redirect:/";
    }


    @RequestMapping("/canvas/add")
    public String addCanvas(@ModelAttribute("canvases") Canvas canvas,Model model){
The method below uses Spring Security to find out who is logged in.
        Person person = personService.getCurrentlyAuthenticatedUser();
        model.addAttribute("canvases",new Canvas());
        model.addAttribute("listCanvas", this.canvasService.listCanvases());
        model.addAttribute("listCanvases",this.canvasService.listCanvasPerson(person));
        this.canvasService.addCanvas(canvas,person);
        return "redirect:/canvas/list";
    }

spring hibernate多对多映射表单输入

1 个答案: