如何在Vaadin8表单中验证TextField

public class Person {
    private String name;

    // getter and setter methods
}

public class MyForm extends VerticalLayout {
    private Binder<Person> binder = new Binder<>();

    public MyForm() {
        TextField nameField = new TextField("Name");
        binder.bind(nameField, Person::getName, Person::setName);

        // 添加验证规则
        binder.forField(nameField)
              .asRequired("Name is required")
              .withValidator(name -> name.length() >= 3, "Name must be at least 3 characters long")
              .bind(Person::getName, Person::setName);

        addComponent(nameField);
    }
}

Button submitButton = new Button("Submit", event -> {
    if (binder.validate().isOk()) {
        // 表单验证通过，执行提交操作
        // ...
    }
});