java - Vaadin 8 在一张表单上使用多个 Binder 的问题

Question

我在 Vaadin 8 中的单个表单上绑定(bind)多个 java 对象时遇到问题。

我不确定代码中缺少什么。

下面是我的代码片段:

public Component getSiteForm(SiteRequest requestData, LocationRequest locationRequest, boolean isReadOnly) {

    FormLayout siteForm = new FormLayout();
    siteForm.setStyleName("outlined");
    siteForm.setSizeFull();

    DefaultFormBuilder defaultSiteFormBuilder = new DefaultFormBuilder(siteForm, isReadOnly);
    final BeanValidationBinder<SiteRequest> siteBinder = new BeanValidationBinder<SiteRequest>(SiteRequest.class);
    siteBinder.setBean(requestData);

    final BeanValidationBinder<LocationRequest> locationBinder = new BeanValidationBinder<LocationRequest>(
            LocationRequest.class);
    locationBinder.setBean(locationRequest);

TextField nameField = defaultSiteFormBuilder.getTextField("Site Name");
    siteBinder.bind(nameField, "name");
    nameField.setWidth(SharkManagerConstant.DEFAULT_TEXT_FIELD_SIZE);

TextField zipcodeField = defaultSiteFormBuilder.getTextField("Zipcode");
    locationBinder.forField(zipcodeField).withNullRepresentation("560047")
            .withConverter(new StringToLongConverter("Please enter Zipcode")).bind("zipcode");
    zipcodeField.setWidth(SharkManagerConstant.DEFAULT_TEXT_FIELD_SIZE);
return siteForm;
}

SiteRequest类如下:

import java.io.Serializable;
import java.sql.Time;
import java.util.Date;

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;


public class SiteRequest implements Serializable {
/**
 * 
 */
private static final long serialVersionUID = 1L;

@NotNull
@Size(min = 1, max = 40)
private String name;

/**
 * @return the name
 */
public String getName() {
    return name;
}

/**
 * @param name
 *            the name to set
 */
public void setName(String name) {
    this.name = name;
}
}

LocationRequest类如下:

import java.io.Serializable;

import javax.validation.constraints.NotNull;

public class LocationRequest implements Serializable {

private static final long serialVersionUID = 1L;

private Long zipcode;

public Long getZipcode() {
    return zipcode;
}

public void setZipcode(Long zipcode) {
    this.zipcode = zipcode;
}

}

我在编辑表单时收到 ClassCastException。虽然我已经把 String 转换为 Long 了。

不确定这是否是 Vaadin 中的错误。

Answer 1

我猜你的 withNullRepresentation 和 withConverter 的交互在这里是有问题的(withNullRepresentation 创建了一个特定的转换器，所以这可能是它)。您可以尝试颠倒 withConverter 和 withNullRepresentation 调用的顺序，并使用 Long (目标数据类型)而不是 String 作为空表示。