path: root/src/compiler/scala/tools/nsc/ObjectRunner.scala

package scala.tools.nsc
import java.net.URLClassLoader
import java.io.File
import java.lang.reflect.{Method,Modifier}

/** An object that runs another object specified by name. */
object ObjectRunner {
  def isMainMethod(meth: Method): Boolean = {
    def paramsOK(params: Array[Class]): Boolean = {
      (params.length == 1) &&
      (params(0) == classOf[Array[String]])
    }
    meth.getName == "main" &&
    Modifier.isStatic(meth.getModifiers) &&
    paramsOK(meth.getParameterTypes)
  }

  def run(
      classpath: List[String],
      objectName: String,
      arguments: Seq[String]): Unit =
  {
    val classpathURLs = classpath.map(s => new File(s).toURL).toArray
    val mainLoader  = new URLClassLoader(classpathURLs, null)
    val clsToRun = Class.forName(objectName, true, mainLoader)

    val method = clsToRun.getMethods.find(isMainMethod) match {
      case Some(meth) => meth
      case None => {
        throw new Error("no main method in object " + objectName)
      }
    }
    val res = method.invoke(null, List(arguments.toArray).toArray)
    ()
  }
}