考虑一个注册表单,其中包含一些字段,如本bean所述
public class RegistrationEntity {
private Long accountNumber;
private String firstName;
private String middleName;
private String lastName;
private Long phoneNumber;
private String emailId;
private Long communicationHouseNo;
private String communicationStreet;
private Long communicationPincode;
private Long communicationLandLine;
private String communicationLandmark;
private Long permenantHouseNo;
private String permenantStreet;
private Long permenantPincode;
private Long permenantLandLine;
private String permenantLandmark;
}
以及由此
设计的组件 RegistrationEntity bean = new RegistrationEntity();
BeanItem<RegistrationEntity> item = new BeanItem<RegistrationEntity>(bean);
fieldGroup = new FieldGroup(item);
firstName = new TextField("First Name");
firstName.setRequired(true);
firstName.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(firstName, "firstName");
lastName = new TextField("Last Name");
lastName.setRequired(true);
lastName.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(lastName, "lastName");
dateOfBirth = new DateField("Date of birth");
dateOfBirth.setRequired(true);
dateOfBirth.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(dateOfBirth, "dateOfBirth");
mothersMaidenName = new TextField("Mother's Maiden name;");
mothersMaidenName.setRequired(true);
mothersMaidenName.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(mothersMaidenName, "motherName");
email = new TextField("User:");
email.setRequired(true);
email.setInputPrompt("Your username (eg. joe@email.com)");
email.addValidator(new EmailValidator(
"Username must be an email address"));
email.setInvalidAllowed(false);
email.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(email, "emailId");
panNo = new TextField("PAN:");
panNo.setRequired(true);
panNo.setWidth(COMMON_FIELD_WIDTH);
fieldGroup.bind(panNo, "panNumber");
这会在初始化时使用空值绑定组件 但我希望组件显示空值而不是null 当用户点击某个特定按钮时,只有这些值应绑定到bean,以后可用于持久性
答案 0 :(得分:0)
您可以使用setNullRepresentation()来实现此目的。
https://vaadin.com/de/book/-/page/components.textfield.html
这样,您可以告诉TextField当值为NULL时要显示的内容
答案 1 :(得分:0)
你应该使用
setNullRepresentation(&#34;&#34;);
例如:
firstName.setNullRepresentation(&#34;&#34;);
尝试这种方式,以便在您尝试注册时不会显示空值。