Java 在 IntelliJ 中找不到类文件
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Class file not found in IntelliJ
提问by homaxto
In IntelliJ I get this weird error when I try to compile.
在 IntelliJ 中，当我尝试编译时出现这个奇怪的错误。
Cannot find annotation method 'cascade()' in type 'javax.persistence.ManyToOne': class file for javax.persistence.ManyToOne not found
I know, it seems pretty obvious what the problem is, but having spent too much time on this problem I now turn my trust to you!
我知道，问题出在哪里似乎很明显，但是在这个问题上花费了太多时间，我现在将信任转向您！
I use ideaCommunity-9, where I have created a global library for JBoss, which contains all JBoss jars including ejb3-persistence.jar. My module includes this library, and I have moved it to the top of dependencies.
No otherwhere in classpath I have a javax.persistence.ManyToOne class, and it also opens up in IntelliJ without problems.
If I open the file where I get the compile error, IntelliJ shows no problems and also navigates to the class file on pressing Ctrl+B.
The code is also build with ant and here it works fine.
我使用ideaCommunity-9，我在其中为JBoss 创建了一个全局库，其中包含所有JBoss jar，包括ejb3-persistence.jar。我的模块包含这个库，我已经将它移到依赖项的顶部。在类路径中没有其他地方我有一个 javax.persistence.ManyToOne 类，它也在 IntelliJ 中打开没有问题。
如果我打开出现编译错误的文件，IntelliJ 不会显示任何问题，并且还会在按 Ctrl+B 时导航到类文件。
代码也是用 ant 构建的，在这里它工作正常。
Besides the above error I get six others along the same path (name in Table, etc.) - all related to JPA. I also get a message saying "Please file a bug to JDC yada yada yada."
除了上述错误之外，我还得到了其他六个相同路径（表中的名称等）——所有这些都与 JPA 相关。我还收到一条消息，说“请向 JDC yada yada yada 提交错误。”
采纳答案by Roman
Try to tick a checkbox "export" in your dependencies.
尝试在您的依赖项中勾选“导出”复选框。
I mean: "File" menu -> Project Structure -> Modules -> Dependencies, and there you can see libs included to the module. You should also see a checkbox near each lib in column 'Export'.
我的意思是：“文件”菜单 -> 项目结构 -> 模块 -> 依赖项，在那里你可以看到模块中包含的库。您还应该在“导出”列中的每个库附近看到一个复选框。
回答by VonC
Isn't that similar to this SO question?
这不是类似于this SO question吗？
The solution there was to add all JBoss jar (which you did), but also all persistent-related libraries (like Hibernate)
那里的解决方案是添加所有 JBoss jar（您所做的），以及所有与持久相关的库（如 Hibernate）
See this JBoss project configurationfor example:
例如，请参阅此JBoss 项目配置：
alt text http://jdick.co.uk/blog/wp-content/uploads/2008/12/projectstructure1.jpg
替代文字 http://jdick.co.uk/blog/wp-content/uploads/2008/12/projectstructure1.jpg
In short, ejb3-persistence.jarmight not be the problem here, just a symptom of otherelements missing.
Or, if it is the problem, it may be related to the fact that it is not deployed correctly (for the WebApp configuration).
简而言之，ejb3-persistence.jar可能不是这里的问题，只是缺少其他元素的症状。
或者，如果是问题，则可能与未正确部署有关（对于WebApp 配置）。
回答by Yuval F
Here's an idea:
Maybe you have multiple versions of your jar file.
Search your folder hierarchy for the file ejb3-persistence.jar,
using a file management tool such as Total Commander.
Multiple appearances of the file in your classpath may confuse IntelliJ Idea
into not recognizing the proper class in the proper jar.
这是一个想法：也许您有多个版本的 jar 文件。ejb3-persistence.jar使用文件管理工具（例如 Total Commander）搜索文件的文件夹层次结构。类路径中文件的多次出现可能会使 IntelliJ Idea 混淆，无法识别正确 jar 中的正确类。
回答by rogerdpack
had a similar problem ("cannot find class spring...DefaultResourceLoader even though it wasin my maven dependencies) and no amount of tweaking of revalidating caches seemed to help. Blowing away my $HOME/.Idea* paths and (basically) starting from scratch fixed it for me. At least for now...
也有类似的问题（“无法找到班春... DefaultResourceLoader即使它是在我的Maven依赖），并没有重新验证缓存的调整量似乎帮助。吹走我的$ HOME / .Idea *路径和（基本）开始从头开始为我修复它。至少现在......
回答by Buddha
I'm sure, it is too late to answer, but I had to follow a different approach for this error to resolve this issue.
我敢肯定，现在回答为时已晚，但我必须针对此错误采用不同的方法来解决此问题。
I had to create this as global library and add that library to the module, then only the error is resolved.
我必须将其创建为全局库并将该库添加到模块中，然后才解决了错误。
回答by Nick Grealy
I was getting the class not founderror message when trying to execute a .groovytest class, which referenced a .groovyfile (located in the root of the source directory of a submodule - i.e. no packages).
我class not found在尝试执行一个.groovy测试类时收到错误消息，该类引用了一个.groovy文件（位于子模块源目录的根目录中 - 即没有包）。
Moving the source file .groovyinto a package, fixed the issue for me.
将源文件移动.groovy到一个包中，为我解决了这个问题。
Move:
移动：
src/main/groovy/RunMe.groovy
to
到
src/main/groovy/somePackage/RunMe.groovy
回答by developer747
In intelliJ I got this problem when I built (ctrl+shift+F9) at the file level.
在 intelliJ 中，我在文件级别构建 (ctrl+shift+F9) 时遇到了这个问题。
The reason is, I had changes in other files in the same maven project, that were not getting picked.
原因是，我在同一个 Maven 项目中的其他文件中进行了更改，但没有被选中。
I solved it by building at the project level (Select the Maven project in intellij and press ctrl+shift+F9)
我通过在项目级别构建解决了它（在intellij中选择Maven项目并按ctrl+shift+F9）
回答by plosco
Just got this myself but non of those things were my issue. I downloaded a project from github, then opened in intelli J with the problem after trying to run a junit test.
我自己刚拿到这个，但这些都不是我的问题。我从github下载了一个项目，然后在尝试运行junit测试后在intelli J中打开了这个问题。
Solution: Project Structure -> Modules -> 'Project_Name' -> Sources (tab) -> click src folder -> Mark as: Sources
解决方案：项目结构 -> 模块 -> 'Project_Name' -> Sources (tab) -> 点击 src 文件夹 -> 标记为：Sources
This should highlight src to be blue and all the class files should be the circles with C instead of looking like normal files. Try running a test again and see if that does it.
这应该将 src 突出显示为蓝色，并且所有类文件都应该是带有 C 的圆圈，而不是看起来像普通文件。尝试再次运行测试，看看是否可以。
