How to read files from resources folder in Scala

Question

I have a folder structure like below   - main -- java -- resources  -- scalaresources --- commandFiles    and in that folders I have my files that I have to read  Here is the code   def readData runtype  String  snmphost  String  comstring  String  specificType   String   Unit       val realOrInvFile     commandFiles snmpcmds    runtype trim    these files are under commandFiles folder  which I have to read       try         if  specificType equalsIgnoreCase  Cisco              val specificDeviceFile  String     commandFiles snmpcmds   runtype trim    cisco          val realOrInvCmdsList   scala io Source fromFile realOrInvFile  getLines   toList filterNot line   gt  line startsWith       map              some code                    val specificCmdsList   scala io Source fromFile specificDeviceFile  getLines   toList filterNot line   gt  line startsWith       map              some code                         catch         case e  Exception   gt  e printStackTrace

User · Answer

For Scala    2 12  use Source fromResource   scala io Source fromResource  located in resouces any

User · Answer

Resources in Scala work exactly as they do in Java   It is best to follow the Java best practices and put all resources in src main resources and src test resources   Example folder structure   testing styles   -- build sbt  -- src         -- main             -- resources                    -- readme txt   Scala 2 12 x  amp  amp  2 13 x reading a resource  To read resources the object Source provides the method fromResource   import scala io Source val readmeText   Iterator String    Source fromResource  readme txt   getLines   reading resources prior 2 12  still my favourite due to jar compatibility   To read resources you can use getClass getResource and getClass getResourceAsStream    val stream  InputStream   getClass getResourceAsStream   readme txt   val lines  Iterator String    scala io Source fromInputStream  stream   getLines   nicer error feedback  2 12 x  amp  amp  2 13 x   To avoid undebuggable Java NPEs  consider   import scala util Try import scala io Source import java io FileNotFoundException  object Example      def readResourceWithNiceError resourcePath  String   Try Iterator String          Try Source fromResource resourcePath  getLines         recover throw new FileNotFoundException resourcePath        good to know  Keep in mind that getResourceAsStream also works fine when the resources are part of a jar  getResource  which returns a URL which is often used to create a file can lead to problems there    in Production  In production code I suggest to make sure that the source is closed again

User · Answer

import scala io Source  object Demo      def main args  Array String    Unit          val ipfileStream   getClass getResourceAsStream  quot  folder a-words txt quot       val readlines   Source fromInputStream ipfileStream  getLines     readlines foreach readlines   gt  println readlines

User · Answer

For Scala 2 11  if getLines doesn t do exactly what you want you can also copy the a file out of the jar to the local file system    Here s a snippit that reads a binary google  p12 format API key from  resources  writes it to  tmp  and then uses the file path string as an input to a spark-google-spreadsheets write   In the world of sbt-native-packager and sbt-assembly  copying to local is also useful with scalatest binary file tests  Just pop them out of resources to local  run the tests  and then delete   import java io  File  FileOutputStream  import java nio file  Files  Paths   def resourceToLocal resourcePath  String        val outPath     tmp     resourcePath   if   Files exists Paths get outPath          val resourceFileStream   getClass getResourceAsStream s    resourcePath        val fos   new FileOutputStream outPath      fos write        Stream continually resourceFileStream read  takeWhile -1     map   toByte  toArray           fos close         outPath    val filePathFromResourcesDirectory    google-docs-key p12  val serviceAccountId     something  drive-integration- something  iam gserviceaccount com  val googleSheetId    1nC8Y3a8cvtXhhrpZCNAsP4MBHRm5Uee4xX-rCW3CW 4  val tabName    Favorite Cities   import spark implicits val df   Seq   Brooklyn    New York                 New York City    New York                 San Francisco    California               toDF  City    State    df write    format  com github potix2 spark google spreadsheets      option  serviceAccountId   serviceAccountId     option  credentialPath   resourceToLocal filePathFromResourcesDirectory      save s   googleSheetId    tabName

User · Answer

The required file can be accessed as below from resource folder in scala  val file   scala io Source fromFile s src main resources app config   getLines   mkString

User · Answer

Onliner solution for Scala  gt   2 12 val source html   Source fromResource  quot file html quot   mkString

[scala] How to read files from resources folder in Scala?

Examples related to scala

Examples related to scala-collections