如何构建、编译和运行Scala项目？
我想评估我在Github上发现的一个Scala项目，即 我找到了构建文件如何构建、编译和运行Scala项目？,scala,sbt,Scala,Sbt,我想评估我在Github上发现的一个Scala项目，即 我找到了构建文件build.sbt。我设法通过自制安装了Scala和sbt，然后在项目根文件夹上运行命令sbt run。这样做会导致一个错误： java.lang.RuntimeException: No main class detected. at scala.sys.package$.error(package.scala:27) 现在，项目文件位于src/main/scala/io/mem0r1es/trank中，当我尝试
build.sbtsbt runjava.lang.RuntimeException: No main class detected.
at scala.sys.package$.error(package.scala:27)
src/main/scala/io/mem0r1es/trankscalacsbt run对象排名不是包io.mem0r1es.trank的成员
如果您能帮助我了解如何运行这个Scala项目，我将不胜感激。TRank是一个SBT项目。您需要从此站点安装SBT
然后您可以这样构建它：
sbt clean compile package
这将在目标/文件夹中为您创建一个jar文件。一旦获得jar文件，就可以像使用Java jar文件一样使用它（除了必须使用scala自动包含scala库jar之外）：
正如您已经注意到的，该项目由sbt管理
为了打包一个项目，即创建一个包含所有应该分发的项目工件的jar，您需要执行package
> package
[info] Updating {file:/Users/jacek/sandbox/TRank/}trank...
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[info] Done updating.
[info] Compiling 13 Scala sources to /Users/jacek/sandbox/TRank/target/scala-2.10/classes...
[warn] there were 1 deprecation warning(s); re-run with -deprecation for details
[warn] one warning found
[info] Packaging /Users/jacek/sandbox/TRank/target/scala-2.10/trank_2.10-1.0.jar ...
[info] Done packaging.
默认情况下，sbt管理src/main/scala
目录下的源。您可以在那里找到要运行的应用程序
对象
在sbt中，run
搜索src/main/scala
下的所有源以查找应用程序
> help run
Runs a main class, passing along arguments provided on the command line.
如果项目没有主类，则会打印错误：
> run
java.lang.RuntimeException: No main class detected.
at scala.sys.package$.error(package.scala:27)
[trace] Stack trace suppressed: run last compile:run for the full output.
[error] (compile:run) No main class detected.
[error] Total time: 0 s, completed Sep 24, 2014 9:40:52 PM
这确实意味着该项目没有主类，但还有其他方法可以“证明”API正常工作——使用测试
执行test
启动测试：
> test
[info] Compiling 5 Scala sources to /Users/jacek/sandbox/TRank/target/scala-2.10/test-classes...
[warn] there were 2 feature warning(s); re-run with -feature for details
[warn] one warning found
[info] ANC_DEPTHSpec:
[info] An ANC_DEPTH ranker
[info] - should rank types properly
[info] - should not fail when no types are provided
[info] ANCESTORSSpec:
[info] An ANCESTORS ranker
[info] - should rank types properly
[info] - should not fail when no types are provided
[info] DEPTHSpec:
[info] A DEPTH ranker
[info] - should rank types by maximum depth
[info] - should not fail when no types are provided
Loading classifier from edu/stanford/nlp/models/ner/english.all.3class.distsim.crf.ser.gz ... [info] PreProcessorSpec:
[info] A PreProcessor
[info] - should remove boilerplate from HTML content
[info] - should leave intact textual content
[info] - should not fail with empty content
done [2.8 sec].
[info] NERSpec:
[info] A NER
[info] - should extract entity labels
[info] - should not fail with content without Named Entities
[info] - should not fail with empty content
[info] Passed: Total 12, Failed 0, Errors 0, Passed 12
[success] Total time: 4 s, completed Sep 24, 2014 9:42:09 PM
因此，要了解该项目，您应该查看测试的来源（在src/test/scala
下）以及可以使用doc
任务生成的scaladoc：
> doc
[info] Main Scala API documentation to /Users/jacek/sandbox/TRank/target/scala-2.10/api...
model contains 20 documentable templates
[info] Main Scala API documentation successful.
[success] Total time: 1 s, completed Sep 24, 2014 9:43:22 PM
您还可以使用console
task来输入Scala REPL并自己处理这些类型
> console
[info] Starting scala interpreter...
[info]
Welcome to Scala version 2.10.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_20).
Type in expressions to have them evaluated.
Type :help for more information.
scala>
通过这些测试，scaladoc和Scala REPL，您应该已经准备好学习项目的API了。谢谢您的回答，我已经设法看到了.jar文件，但是当我尝试运行它时，我在trank_2.10-1.0.jar中没有主清单属性。mainscala-cp/path/to/trank_2.10-1.0.jar.com.example.SomeMainClassjava-jarscalajavaclass-TRanker（content:String）：save> console
[info] Starting scala interpreter...
[info]
Welcome to Scala version 2.10.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_20).
Type in expressions to have them evaluated.
Type :help for more information.
scala>