Spring绑定列表<Object>到Form:复选框

Question

我似乎无法将我的表单绑定到复选框控件.我在这里阅读了很多帖子并尝试了一些技巧但没有运气.也许一双新鲜的眼睛会有所帮助.

我的控制器:

public String editAccount(@RequestParam("id") String id, Model model) {
    model.addAttribute("account", accountService.getAccount(id));
    model.addAttribute("allRoles", roleService.getRoles());
    return EDIT_ACCOUNT;
}

我的jsp:

<form:form action="" modelAttribute="account">
<form:checkboxes items="${allRoles}" path="roles" itemLabel="name" itemValue="id" delimiter="<br/>"/>
</form>

生成的html:

<span><input id="roles1" name="roles" type="checkbox" value="1"/><label for="roles1">User</label></span><span><br/><input id="roles2" name="roles" type="checkbox" value="2"/><label for="roles2">Admin</label></span><span><br/><input id="roles3" name="roles" type="checkbox" value="3"/><label for="roles3">SuperAdmin</label></span<input type="hidden" name="_roles" value="on"/>

我为每个循环使用了一秒(未显示)以确保模型对象包含角色.确实如此,但是没有选中复选框,当我提交角色对象时总是为空.有人可以告诉我我错过了什么吗？

谢谢

编辑

抱歉,我们意识到查看帐户和角色对象可能会有所帮助:

public class Account {

    private String username, firstName, lastName, email;
    private List<Role> roles;

    @NotNull
    @Size(min = 1, max = 50)
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @NotNull
    @Size(min = 1, max = 50)
    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @NotNull
    @Size(min = 1, max = 50)
    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @NotNull
    @Size(min = 6, max = 50)
    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public List<Role> getRoles() {
        return roles;
    }

    public void setRoles(List<Role> roles) {
        this.roles = roles;
    }

    public String toString() {
        return ReflectionToStringBuilder.toString(this);
    }

}

public class Role {

private int id;
private String name;

public Role() {}

public Role(int id, String name) {
    this.id = id;
    this.name = name;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

@NotNull
@Size(min = 1, max = 50)
public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

}

编辑#2

控制器发布方法

@RequestMapping(value = "edit", method = RequestMethod.POST)
public String updateAccount(@RequestParam("id") String id, @ModelAttribute("account") @Valid AccountEditForm form, BindingResult result) {
    System.out.println("FORM VALUES AFTER: " + form);
    return (result.hasErrors() ? EDIT_ACCOUNT : ACCOUNT_REDIRECT);
}

AccountEditForm是表单支持对象.当我执行GET时,我会抓取一个Account对象,并在显示屏幕之前将值传递给AccountEditForm.为了清楚起见,我将附上AccountEditForm.它与帐户对象非常相似.我刚碰巧从模型对象中分离出我的表单对象.

public class AccountEditForm {

    private String username, firstName, lastName, email;
    private List<Role> roles = new ArrayList<Role>();

    @NotNull
    @Size(min = 1, max = 50)
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @NotNull
    @Size(min = 1, max = 50)
    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @NotNull
    @Size(min = 1, max = 50)
    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @NotNull
    @Size(min = 6, max = 50)
    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public List<Role> getRoles() {
        return roles;
    }

    public void setRoles(List<Role> roles) {
        this.roles = roles;
    }

    public String toString() {
        return ReflectionToStringBuilder.toString(this);
    }

}

编辑#3角色属性编辑器

public class RolePropertyEditor extends PropertyEditorSupport {

    private Map<Integer, Role> roleMap = new HashMap<Integer, Role>();

    public RolePropertyEditor(List<Role> roleList) {
        for (Role r : roleList) roleMap.put(r.getId(), r);
    }

    public void setAsText(String incomingId) {
        Role role = roleMap.get(incomingId);
        System.out.println("PROPERTY EDITOR ROLE " + role);
        setValue(role);
    }

    public String getAsText() {
        System.out.println("PROPERTY EDITOR ID " + ((Role)getValue()).getId());
        return String.valueOf(((Role)getValue()).getId());
    }
}

在我的控制器中定义如下:

@InitBinder
public void initBinder(WebDataBinder binder) {
    binder.setAllowedFields(new String[] {
            "username", "password", "confirmPassword", "firstName", "lastName", "email", "acceptTerms", "currentPassword"
    });
    binder.registerCustomEditor(Role.class, new RolePropertyEditor(roleService.getRoles()));
}

编辑#4新ProeprtyEditor

public class SecurityRolePropertyEditor extends PropertyEditorSupport {

    private RoleService roleService;

    public SecurityRolePropertyEditor(RoleService roleService) {
        this.roleService = roleService;
    }

    public void setAsText(final String name) {
        Role role = roleService.getRoleByName(name);
        setValue(role);
    }
}

Answer 1

将 equals 方法添加到您的 Roles 实体。

请参阅此答案（Spring MVC Pre Populate Checkboxes）：类似问题的更多详细信息。