vaadin - 如何将 Vaadin DateField 绑定(bind)到 LocalDateTime

Question

Vaadin docs显示如何将 DateField 与 java.util.Date 一起使用，但我想将 DateField 与 BeanFieldGroup 绑定(bind)到 Java 8 类型 java.time.LocalDateTime 的 bean 属性。我怎样才能做到这一点？

Answer 1

似乎是 Vaadin Converter是要走的路:

package org.raubvogel.fooddiary.util;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.util.Date;
import java.util.Locale;

import com.vaadin.data.util.converter.Converter;

/**
 * Provides a conversion between old {@link Date} and new {@link LocalDateTime} API.
 */
public class LocalDateTimeToDateConverter implements Converter<Date, LocalDateTime> {

    private static final long serialVersionUID = 1L;

    @Override
    public LocalDateTime convertToModel(Date value, Class<? extends LocalDateTime> targetType, Locale locale)
            throws com.vaadin.data.util.converter.Converter.ConversionException {

        if (value != null) {
            return value.toInstant().atZone(ZoneOffset.systemDefault()).toLocalDateTime();
        }

        return null;
    }

    @Override
    public Date convertToPresentation(LocalDateTime value, Class<? extends Date> targetType, Locale locale)
            throws com.vaadin.data.util.converter.Converter.ConversionException {

        if (value != null) {
            return Date.from(value.atZone(ZoneOffset.systemDefault()).toInstant());
        }

        return null;
    }

    @Override
    public Class<LocalDateTime> getModelType() {
        return LocalDateTime.class;
    }

    @Override
    public Class<Date> getPresentationType() {
        return Date.class;
    }

}

灵感来自 this link在 LocalDate 和 Date 之间转换。需要通过 setConverter 或通过 converter factory 将转换器设置为 DateField .