JPA属性java.net.URL [英] JPA property java.net.URL

问题描述

HI，

我有一个对象，其中包含一段与之关联的URL信息。
目前我将此URL保存在一个简单的String属性中，但是java.net.URL会为
提供额外的好处，例如检测格式错误的URL等。

I have an object which has a piece of URL-Information associated with it. Currently I save this URL in a simple String property, but java.net.URL would provide me with additional goodies such as detection of malformed URLs etc.

另一方面，如果JPA只是为URL-Object创建了一个LOB，我认为它非常难看。有没有人知道java.net.URL类型的属性将如何通过兼容的JPA提供程序持久保存到
数据库？

On the other hand I would consider it very ugly, if JPA simply created a LOB for the URL-Object. Does anyone know how a property of the type java.net.URL will be persisted to the database by compliant JPA providers?

推荐答案

根据JPA规范：

的持久性字段或属性实体可能具有以下类型：
Java原始类型; java.lang.String中;
其他Java可序列化类型
（包括原始
类型的包装，java.math.BigInteger，
java.math.BigDecimal，java.util.Date，
java.util.Calendar [7]，java.sql.Date，
java.sql.Time，java.sql.Timestamp，
user-de fi ned serializable types，byte []，
Byte []，char []和字符[]）;
enums;实体类型和/或
实体类型集合;和
嵌入类（参见
2.1.5节）。

The persistent fields or properties of an entity maybe of the following types: Java primitive types; java.lang.String; other Java serializable types (including wrappers of the primitive types, java.math.BigInteger, java.math.BigDecimal, java.util.Date, java.util.Calendar[7], java.sql.Date, java.sql.Time, java.sql.Timestamp, user-defined serializable types, byte[], Byte[], char[], andCharacter[]); enums; entity types and/or collections of entity types; and embeddable classes (see section 2.1.5).

加上对集合的支持。但没有 URL 的原始支持。然而，它们将被支持为 Serializable ，我想这将导致你提到的LOB。

Plus the support for collections. But no primitive support of URL. They would however be supported as Serializable, which I guess would result in a LOB as you mentioned.

但您应该能够轻松规避：您可以在一个字段中将URL作为 String 但是，getter / setter可以从 String 转换为 URL 。然后使用注释映射该字段。

But you should be able to easily circumvent that: you can have the URL as a String in a field and a getter/setter that convert from String to URL though. Then you map the field with the annotation.

或相反：字段中的 java.lang.URL ，以及从<转换的getter / setter code> URL 到 String ，然后使用注释映射getter / setter。我认为它也有效。

Or the opposite: the java.lang.URL in a field, and getter/setter to convert from URL to String, then you map the getter/setter with the annotation. I think it works as well.

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