sbt命令抛出空指针异常

Question

我是scala和sbt的新手,我想运行sbt命令但是我得到一些Nullpointer异常,不知道为什么.

我在系统中安装了scala:

scala -version Scala代码运行器版本2.11.8 - 版权所有2002-2016,LAMP/EPFL

此外,如果我尝试检查sbt版本工作正常:

sbt --version sbt launcher version 0.13.5

但是当我运行sbt时,我得到一个例外:

  info] Loading project definition from /home/workspace/myproject
    java.lang.NullPointerException
        at java.util.regex.Matcher.getTextLength(java.base@9-internal/Matcher.java:1747)
        at java.util.regex.Matcher.reset(java.base@9-internal/Matcher.java:402)
        at java.util.regex.Matcher.<init>(java.base@9-internal/Matcher.java:244)
        at java.util.regex.Pattern.matcher(java.base@9-internal/Pattern.java:1108)
        at java.util.regex.Pattern.split(java.base@9-internal/Pattern.java:1221)
        at java.util.regex.Pattern.split(java.base@9-internal/Pattern.java:1288)
        at sbt.IO$.pathSplit(IO.scala:744)
        at sbt.IO$.parseClasspath(IO.scala:859)
        at sbt.compiler.CompilerArguments.extClasspath(CompilerArguments.scala:62)
        at sbt.compiler.MixedAnalyzingCompiler$.withBootclasspath(MixedAnalyzingCompiler.scala:189)
        at sbt.compiler.MixedAnalyzingCompiler$.searchClasspathAndLookup(MixedAnalyzingCompiler.scala:167)
        at sbt.compiler.MixedAnalyzingCompiler$.apply(MixedAnalyzingCompiler.scala:177)
        at sbt.compiler.IC$.incrementalCompile(IncrementalCompiler.scala:138)
        at sbt.Compiler$.compile(Compiler.scala:128)
        at sbt.Compiler$.compile(Compiler.scala:114)
        at sbt.Defaults$.sbt$Defaults$$compileIncrementalTaskImpl(Defaults.scala:814)
        at sbt.Defaults$$anonfun$compileIncrementalTask$1.apply(Defaults.scala:805)
        at sbt.Defaults$$anonfun$compileIncrementalTask$1.apply(Defaults.scala:803)
        at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
        at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
        at sbt.std.Transform$$anon$4.work(System.scala:63)
        at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
        at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
        at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
        at sbt.Execute.work(Execute.scala:235)
        at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
        at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
        at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
        at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
        at java.util.concurrent.FutureTask.run(java.base@9-internal/FutureTask.java:266)
        at java.util.concurrent.Executors$RunnableAdapter.call(java.base@9-internal/Executors.java:514)
        at java.util.concurrent.FutureTask.run(java.base@9-internal/FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@9-internal/ThreadPoolExecutor.java:1158)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@9-internal/ThreadPoolExecutor.java:632)
        at java.lang.Thread.run(java.base@9-internal/Thread.java:804)
    [error] (compile:compileIncremental) java.lang.NullPointerException

知道如何解决这个问题吗？

Answer 1

堆栈跟踪

Loading project definition from /home/workspace/myproject
    java.lang.NullPointerException
        at java.util.regex.Matcher.getTextLength(java.base@9-internal/Matcher.java:1747)
        at java.util.regex.Matcher.reset(java.base@9-internal/Matcher.java:402)
        at java.util.regex.Matcher.<init>(java.base@9-internal/Matcher.java:244)
        at java.util.regex.Pattern.matcher(java.base@9-internal/Pattern.java:1108)
        at java.util.regex.Pattern.split(java.base@9-internal/Pattern.java:1221)
        at java.util.regex.Pattern.split(java.base@9-internal/Pattern.java:1288)

表示您尝试在 JDK 9 下运行 sbt 0.13.5，当时该版本不受支持。正如渴求乌鸦在评论中所建议的，推荐的做法是使用 JDK 8。

如果您使用的是 JDK 9 或 10，则使用最新的启动脚本，sbt 1.1.6 或更高版本应该可以更好地工作。