Java Spring表单复选框-通过toString（）匹配，从而勾选错误的复选框

我有一个域对象ContactGroup，其中包含对另一个域对象Person的大量引用：

@Entity
public class ContactGroup {

@ManyToMany
private Set<Person> members = new HashSet<>();

  [...]
}

 <form:checkboxes path="members" multiple="true" items="${personList}" itemLabel="displayString" itemValue="id"/>

@InitBinder
public void initBinder(WebDataBinder binder) {
    binder.setValidator(validator);

    binder.registerCustomEditor(Person.class, new PropertyEditorSupport() {
        @Override
        public void setAsText(String text) throws IllegalArgumentException {
            setValue(personService.get(Long.parseLong(text)));
        }

    });

    binder.registerCustomEditor(Set.class, "members", new CustomCollectionEditor(Set.class) {
        @Override
        protected Object convertElement(Object element) {
            if (element instanceof Long) {
                return personService.get((Long) element);
            } else if (element instanceof String) {
                personService.get(Long.parseLong((String) element));
            } else if (element instanceof Person) {
                return element;
            }
            return null;
        }

    });
}