无法将布尔值设置为空 [英] Cannot set boolean to null

问题描述

我有一个带有以下变量的商店：

  @Column（columnDefinition =bit）
 private boolean atShop; 
  

使用这个值，我使用HSQL从应用程序中检索这些信息

  from Person person 
 left join fetch person.shop 
  

当我尝试调用这个HSQL语句时，我得到以下错误：

$ p $ org.springframework。 orm.hibernate3.HibernateSystemException：无法通过com.test.dataobject.Shop.atShop的反射设置器设置字段值;嵌套异常是org.hibernate.PropertyAccessException：无法通过com.test.dataobject.Shop.atShop的反射设置器设置字段值


它抛出这个是因为它试图在HSQL中将布尔值设置为null。我可以通过更改私人布尔atShop; 到私人布尔atShop; 来解决这个问题，但我想保留这个作为 boolean 因为我将它保存在我的数据库中

有没有办法解决这个问题， code>布尔到布尔？

编辑：

我知道布尔值只能是true / false，布尔值可以设置为null，但是有没有办法让hibernate / spring设置这个值到假（我认为它应该自动执行），而不是试图将其设置为空，并引发此异常？

我也尝试添加注释来自动设置值为false，但这也不起作用

$ $ p $ $ $ c $ @Column（nullable = false，columnDefinition =bit default 0）
私人布尔atShop;

解决方案

- boolean 是一个原始类型，并且可以只有 true或false 。

- 鉴于布尔值是包装对象一个 null 值。

- 从 Java 1.5 提供了 AutoBoxing ，所以你可以将布尔转换为布尔值，然后返回布尔值，使用简单的赋值操作符（ = ），所以你可以在你想要布尔而不是布尔值的地方做到这一点。

I have a class Shop with the following variable

@Column(columnDefinition = "bit")
private boolean atShop;

Using this value, I am using HSQL to retrieve this information from the application

from Person person
left join fetch person.shop

when I try call this HSQL statement i get the following error

org.springframework.orm.hibernate3.HibernateSystemException: could not set a field value by reflection setter of com.test.dataobject.Shop.atShop; nested exception is org.hibernate.PropertyAccessException: could not set a field value by reflection setter of com.test.dataobject.Shop.atShop

It is throwing this because it is trying to set the boolean to null in the HSQL. I can solve this problem by changing private boolean atShop; to private Boolean atShop; but i want to keep this as a boolean as i am saving it as a bit in my database

Is there a way to solve this without changing boolean to Boolean?

EDIT:

I know that boolean can only be true/false and Boolean can be set to null, but is there a way to get hibernate/spring to set this value to false(which i thought it should do automatically) instead of trying to set it to null and throwing this exception?

I have also tried adding annotation to automatically set the value to false but this does not work either

@Column(nullable = false, columnDefinition = "bit default 0")
private boolean atShop;

解决方案

- boolean is a primitive type, and can have a value of only true or false.

- Whereas Boolean is a Wrapper Object and can be given a null value.

- From Java 1.5 AutoBoxing is provided, so you can convert boolean to Boolean and back to boolean with Simple assignment operator (=), So you can do this in places where you want Boolean instead of boolean.

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