问题描述
我在 Scala 中使用了一个库，比如 A，它依赖于另一个库的 x.11 版本，比如 Z.
I am using a library say A in Scala which is dependent on version x.11 of another library say Z.
现在，我还使用了一个库，比如 B，它依赖于 Z 的 x.31 版本.
Now, I am also using a library say B which is dependent on version x.31 of Z.
这会导致编译错误，因为我们将有两个版本的库 Z，如何在 Scala 的 sbt 中同时使用库 A 和 B?有什么办法可以指定.
This leads to compile error because we will have two versions of library Z, how can I use both libraries A and B in scala's sbt? Is there any way to specify it.
推荐答案
如果用更新的版本完全替换一个依赖项碰巧有效，那么 Sparko 的解决方案也有效.然而，情况并非总是如此.
If completely replacing one dependency with a newer version happens to work, then Sparko's solution works. However, that isn't always the case.
如果要在 sbt-assembly 生成的 uber-jar 中包含库的两个版本，则需要使用着色.请参阅这篇博文，了解什么是着色以及与之相关的一些缺点.
If you want to include both versions of a library in the uber-jar produced by sbt-assembly, you'll need to use shading. See this post for an overview of what shading is, and some of the drawbacks associated with it.
着色在 sbt-assembly 的文档这里中有介绍，但如果您是像我这样的人，他们的解释方式会让你比开始时更困惑.有一篇很好的博客文章，Spark, Uber Jars 和 Shading with sbt-assembly (waybackmachine 链接)，这有助于揭开它的神秘面纱.这是相关部分:
Shading is covered in sbt-assembly's documentation here, but if you're anything like me, their way of explaining it will leave you more confused than you started. There's a good blog post, Spark, Uber Jars and Shading with sbt-assembly (waybackmachine link), that helps to demystify it a bit. Here's the relevant section:
我可以遮蔽我的类型安全配置版本，给它一个不同的名称，因此 Spark 不会在版本之间混淆.我赶紧去了到我的 build.sbt 文件，并添加以下代码:
assemblyShadeRules in assembly := Seq(
ShadeRule.rename("com.typesafe.config.**"->"my_conf.@1").inLibrary("com.typesafe" % "config" % "1.3.0").inProject)
assemblyShadeRules in assembly := Seq(
ShadeRule.rename("com.typesafe.config.**" -> "my_conf.@1").inLibrary("com.typesafe" % "config" % "1.3.0").inProject )
根据文档，这应该将任何类放在com.typesafe.config 在新包 my_conf 下.
According to the documentation, this should place any class undercom.typesafe.config under the new package my_conf.
对于您的情况，解决方案是在您的 build.sbt 文件中添加如下内容:
For your case, the solution would be adding something like this to your build.sbt file:
assemblyShadeRules in assembly := Seq(
ShadeRule.rename("com.somecompany.**" -> "my_conf.@1")
.inLibrary("com.somecompany" % "libraryZ" % "0.11")
.inProject
)
这篇关于如何在 Scala 中使用多个版本的库?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！