How i can get lineNumber, function name, pkg name in scala? - scala

Question

I try to google it and search give me just java examples...
Thread.currentThread().getStackTrace()(2).getLineNumber
but in worksheet always returned 5, and in working project scala/playframework 2.5 - always 35
I try to play with level, but it does not work.

Answer 1

I understood, for example create services/Log.scala
package services
object Log {
def info(text: String) = {
val systemStr = makeSystemStr
Console.out.println(Console.BLUE + "[INFO] " + systemStr + Console.RESET + text)
}
def makeSystemStr() = {
val fileName = Thread.currentThread().getStackTrace()(3).getFileName
val lineNumber = Thread.currentThread().getStackTrace()(3).getLineNumber
val cnArr = Thread.currentThread().getStackTrace()(3).getClassName.split("[$]")
val pkgName = cnArr(0).split("[.]")(0)
val name = cnArr(0).split("[.]")(1)
val defName = cnArr(3)
s"$pkgName : $fileName : $name : $defName : line $lineNumber - "
}
}
Then in controller
package controllers
import play.api.mvc._
import services.Log
class SomeCtrl extends Controller {
def Index = Action { request =>
Log.info("some text")
Ok("ok")
}
}

Answer 2

use macro , you can easy to get lineNumber and fileName
//edit
import scala.language.experimental.macros
import scala.reflect.macros.blackbox
object SrcFile {
def currentLine: Int = macro SrcFileImpl.currentLine
def currentFileName: String = macro SrcFileImpl.currentFileName
def currentPackage: String = macro SrcFileImpl.currentPackage
def currentClassName: String = macro SrcFileImpl.currentClassName
def currentFuncName :String = macro SrcFileImpl.currentFuncName
}
class SrcFileImpl(val c: blackbox.Context) {
import c.universe._
def getPackage(symbol: Symbol): String =
if(symbol.isPackage) symbol.fullName else getPackage(symbol.owner)
def getClass(symbol: Symbol): String =
if(symbol.isClass) symbol.name.toTypeName.toString else getClass(symbol.owner)
def currentPackage: c.Expr[String] = c.Expr(q"${getPackage(c.internal.enclosingOwner)}")
def currentFileName: c.Expr[String] = c.Expr(q"${c.enclosingPosition.source.file.name}")
def currentLine: c.Expr[Int] = c.Expr(q"${c.enclosingPosition.line}")
def currentClassName: c.Expr[String] = c.Expr(q"${getClass(c.internal.enclosingOwner)}")
def currentFuncName: c.Expr[String] = c.Expr(q"${c.internal.enclosingOwner.name.toTermName.toString}")
}
// test
package so
object SrcFileTest extends App {
def f() = {
println(SrcFile.currentFileName)
println(SrcFile.currentLine)
println(SrcFile.currentPackage)
println(SrcFile.currentClassName)
println(SrcFile.currentFuncName)
}
f()
}