Question

我有简单的实体（例如）

 import java.util.Date;
 class People implements Serializable{
   ...
   private Date birthdate; //(getters, setters)
   ...}

UI代码：

 final Binder<People> binder = new Binder<People>(People.class);  ...
 People bean=new  People();
 binder.setBean(bean);
 DateField birthdate = new DateField("date of birth");
 binder.bind(birthdate, "birthdate");

当我从UI中的日历中选择日期时，我得到：

 Caused by: java.lang.ClassCastException: Cannot cast java.time.LocalDate to java.util.Date
at java.lang.Class.cast(Class.java:3369)
at com.vaadin.data.Binder$BindingBuilderImpl.lambda$createConverter$f6099586$1(Binder.java:800)
at com.vaadin.data.Converter.lambda$null$fdd4de71$1(Converter.java:105)
at com.vaadin.data.Result.of(Result.java:91)

我尝试使用

 DateField birthdate = new DateField("birthdate");
 binder.bind(birthdate, "birthdate");
 binder.forField(birthdate).withConverter(new LocalDateToDateConverter());

但结果相同。如何正确地将Date绑定到DateField？

Answer 1

问题在于你如何使用binder。而是尝试

DateField birthdate = new DateField("birthdate");
binder.forField(birthdate).withConverter(new LocalDateToDateConverter()).bind("birthdate");

forField方法返回构建器设计模式后面的对象。这意味着你在该对象上调用一些（链式）方法，并通过调用bind来完成它。

vaadin8 DateField：无法将java.time.LocalDate强制转换为java.util.Date

1 个答案: