struct2(六) 为表单添加验证

@Override
    public void validate() {
        if (personBean.getFirstName() == null ||
                personBean.getFirstName().length() == 0) {
            addFieldError("personBean.firstName", "First name is required.");
        }

        if (personBean.getEmail() == null ||
                personBean.getEmail().length() == 0) {
            addFieldError("personBean.email", "Email is required.");
        }

        if (personBean.getEmail() != null &&
                !personBean.getEmail().matches(
                        "^\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$")) {
            addFieldError("personBean.email", "Email format must be right.");
        }
        
        if (personBean.getAge() < 18) {
            addFieldError("personBean.age",
                    "Age is required and must be 18 or older");
        }

    }