java /WEB-INF/classes 与 /WEB-INF/lib
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/WEB-INF/classes vs /WEB-INF/lib
提问by andbi
I'd like to package my Java EE6web classes (beans, filters, servlets) into jar and place it into /WEB-INF/lib/directory along with other utility jars and abandon /WEB-INF/classes/directory totally.
我想将我的Java EE6Web 类（bean、过滤器、servlet）打包到 jar 中，并将其/WEB-INF/lib/与其他实用程序 jar 一起放入目录中，并/WEB-INF/classes/完全放弃目录。
Are there any substantial differences between the two in terms of classloading, acessing application context, etc?
两者在类加载、访问应用程序上下文等方面是否存在实质性差异？
Thanks.
谢谢。
PS: Whenever googling any of java specs I'm always redirected to Oracle documentation index which is dozen clicks away from original url. Anyone knows what's happening there?
PS：每当谷歌搜索任何 Java 规范时，我总是被重定向到 Oracle 文档索引，该索引与原始 url 相距数十次点击。有谁知道那里发生了什么？
回答by Bozho
I'd go for /WEB-INF/classes. It allows you to run your application in debug mode and hot-swap classes on change. If you package everything as a jar, you'd have to repackage and redeploy the app every time you change a class.
我会去的/WEB-INF/classes。它允许您在调试模式下运行您的应用程序，并在更改时热插拔类。如果将所有内容都打包为 jar，则每次更改类时都必须重新打包和重新部署应用程序。
回答by Maxym
Well, shortly: Imagine you have class org.example.Test.class, if you put it into jar and in WEB-INF/lib/directory, and copy the same class into WEB-INF/classes/then classloader of that application will use last one (from WEB-INF/classes/).
好吧，很快：想象一下你有 class org.example.Test.class，如果你把它放到 jar 和 WEB-INF/lib/目录中，并将同一个类复制到WEB-INF/classes/该应用程序的类加载器中，那么该应用程序的类加载器将使用最后一个（来自WEB-INF/classes/）。
Sometimes you can use it as advantage - I have a library, and it has a bug... I look for source of that class (where bug is; I miss the part of how I know that bug is in that class, that's another story), I add that class to the project with fixed code, and it is compiled into WEB-INF/classes/while library still exist in WEB-INF/lib/. Fixed class will be used until library will be fixed.
有时你可以将它用作优势 - 我有一个库，它有一个错误......我寻找那个类的源（错误在哪里；我错过了我如何知道那个错误在那个类中的部分，那是另一个story)，我把那个类添加到项目中，代码固定，WEB-INF/classes/在库仍然存在的时候编译成WEB-INF/lib/. 固定类将被使用，直到库被修复。
回答by ha9u63ar
In Tomcat Servlet container's definition: WEB-INF\classesis searched before WEB-INF\lib. You can choose to delegate your classloading to your custom classloader - even then the order above is maintained.
在 Tomcat Servlet 容器的定义中：WEB-INF\classes在WEB-INF\lib. 您可以选择将您的类加载委托给您的自定义类加载器 - 即使如此，上面的顺序也会保持不变。
If you choose to go with a different provider e.g. JBOss, Glassfish, Jetty it might have a different order, but I am not sure about those.
如果您选择使用不同的提供商，例如 JBOss、Glassfish、Jetty，它可能会有不同的顺序，但我不确定这些。
