sbt run指定 main class

project中有多个class/object定义了main method, 可以这样指定要run的class

方法1：sbt console

sbt> runMain example.Hello

方法2：build.sbt

mainClass in (Compile, run) := Some("ch01.Upper"),
mainClass in (Compile, packageBin) := Some("ch01.Upper"),

sbt例子