无法从百里香叶触及物体

Question

I have a simple project with spring boot/thymeleaf and i have this problem about accessing an object from thymeleaf. I have my user and role objects. Here is my User entity:

@Entity
@Table(name = "users")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    @Column(unique = true)
    private String username;
    private String password;
    private int enabled;
    @ManyToOne
    private Role role;

    // getters and setters...

}

and Role entity:

@Entity
@Table(name = "roles")
public class Role {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String role;

    // getters and setters...
}

controller that i'm providing objects:

@RequestMapping(value = "edit", method = RequestMethod.GET)
public ModelAndView editRoles(){
    ModelAndView modelAndView= new ModelAndView();
    modelAndView.addObject("users", userService.getAll());
    modelAndView.addObject("roles", roleService.getAll());
    modelAndView.setViewName("editRole");
    System.out.println(userService.findUser(2).getRole().getRole());
    return modelAndView;
}

on the page, im trying to edit users roles with a select box. and i want it to show the users role as selected value. but it doesnt work. Here is that code:

<tr th:each="user : ${users}">
    <td >
        <select class="form-control" id="sel1" th:field="*{roles}" >
            <option th:each="role : ${roles}" th:value="${role.id}" th:text="${role.role}" th:selected="${user.role.role}">
            </option>
        </select>
    </td> 
</tr>

the problem is about that user.role.role part. It gives

SpringEL expression

error.

When i use user.role , i can access the role object; but i can't use role's attributes. And the funny part is when i use completely different entities with exactly same configurations, i'm not getting any errors.

Can anybody tell me what's the problem here?

Answer 1

Controller

@RequestMapping(value = "/create", method = RequestMethod.GET)
public String method1(Model model, Principal principal) {
    model.addAttribute("editRole", roles);
    return "HTML_NAME";
}

Controller 2

@RequestMapping(value = "/edit", method = RequestMethod.POST)
public String campaignPost(@ModelAttribute("roles") Roles roles,  Principal principal){
    roles.getName();
    //roles object can be accessed
}

HTML

<form th:action="@{/edit}" method="post" id="formName">
    <select class="form-control" th:value="${objectparamater}" name="gender" id="gender">
        <option disabled="disabled" selected="selected" > -- select the location --</option>
        <option>male</option>
        <option>female</option>
        <option>choose not to tell</option>
    </select>
</form>

I guess this might help You