Eclipse警告：找不到类javax.persistence。* [英] Eclipse Warnings: class javax.persistence.* not found

问题描述

这是我第一次真正使用Eclipse进行Java开发。我正在尝试使用EclipseLink的JPA实现。我将所有实体都移到了一个单独的包实体中。我在一个名为dataModeling的单独JPA项目中有 persistence.xml 。

This is my first time really playing around with Java development using Eclipse. I am trying to use EclipseLink's implementation of the JPA. I moved all of my entities into a separate package "entities". I have the persistence.xml in a separate JPA project called "dataModeling".

所有内容都可以构建并运行良好。

Everything builds and runs fine.

几乎每个项目都取决于我的实体。但是，我看到一个警告未找到类javax.persistence.Entity - 继续使用存根。等，因为依赖项目不引用EclipseLink。

Just about every project depends on my entities. However, I'm seeing a warning Class javax.persistence.Entity not found - continuing with a stub., etc. showing up because the dependent projects don't reference EclipseLink.

解决方案是进入每个依赖项目的属性，在 Java构建路径>库下，单击添加库，然后单击用户库，然后选择 EclipseLink 。

The solution is to go into each dependent project's properties and under Java Build Path > Libraries, click Add Library, then User Library and then select EclipseLink.

但是，对我来说，在每个项目中引用EclipseLink都没有意义！这是一个实现细节我不想给其他项目增加负担。看起来这种情况正在发生，因为其他项目看到了注释并且无法识别它们。

However, to me, it doesn't make sense to reference EclipseLink in every project! That's an implementation detail I don't want to burden other projects with. It looks like this is happening because the other projects see the annotations and don't recognize them.

所以真正的问题是：我如何使用JPA（通过注释）没有其他项目需要引用我的JPA实现？

So the real question is: how can I use JPA (via annotations) without every other project needing to reference my JPA implementation?

推荐答案

感谢@ neil-stockton和@chris，我能够弄清楚发生了什么。大多数JPA实现都有一个javax.persistence JAR的副本在某处浮动。他们中的大多数都与其他一切捆绑在一起，导致我的依赖性噩梦。似乎没有一个事实上的实现浮动。

Thanks to @neil-stockton and @chris, I was able to figure out what was going on. Most JPA implementations have a copy of the javax.persistence JAR floating around somewhere. Most of them are bundled with everything else, leading to my dependency nightmare. There doesn't appear to be a de facto implementation floating around.

在我的情况下，我使用了我的Eclipse插件目录下显示的副本。这些注释真的是空的，因为没有任何不需要的依赖。 JAR文件（ javax.persistence ._< version> .jar ）仅在我添加Dali和EclipseLink插件（一个或另一个）后才出现。

In my case, I used the copy that showed up under my Eclipse plugins directory. These annotations were truly empty in that did not have any unwanted dependencies. The JAR file (javax.persistence._<version>.jar) only showed up after I added the Dali and EclipseLink plugins (one or the other).

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