So I want read a image file in scala worksheet but I don't want use absolute path so others no need to change the code before run, how can I achieve that? the following method return the IDE path, not my project path.
the image file and the worksheet file are in same directory
val path = File(".").toAbsolute //D:\app\idea2016\bin\
System.getProperty("user.dir") //D:\app\idea2016\bin\
Related
I am trying to write a file to a directory without setting an absolute path. I have multi-project build in Intellij and I have a separate directory for files:
-Intellij project
---project-1
---project-2
---project-3
---test-files
And I want to write a file to the files directory without defining an absolute path because I am going to run it on the cluster, where I do not know build path. However, I was able only to reach the root project directory. How can I save files to test-files folder?
Here is the code I use. It saved the file to simply project-1 directory:
val directory = new File("./").getCanonicalPath
import java.io.PrintWriter
val printWriter = new PrintWriter(s"$directory/file.txt")
printWriter.write("This is my string")
printWriter.close()
Try specifying parent directory .. like so
val directory = new File("../test-files")
I'm currently developing a scala library and wanted to get a file that is inside it, event when compiled as a Jar dependency. The problem is that when executed from another project where the library is imported, the path is relative to that project. Here is the code to get the file :
private val pathToDocker: Path = Paths.get("src", "main", "resources", "docker-compose")
What can I do to look for my file inside the imported dependency ?
The file won't be in a file system -- it'll be in the compiled JAR.
You can get a JAR resource using a class loader. Here's an example of how to do that in another codebase.
Utility function:
https://github.com/hail-is/hail/blob/6db198ae06/hail/src/main/scala/is/hail/utils/package.scala#L468
Usage to load version info:
https://github.com/hail-is/hail/blob/6db198ae06/hail/src/main/scala/is/hail/package.scala#L21
There is a JarUtil - from an answer of access-file-in-jar-file translate to Scala:
import java.util.jar.JarFile
val jar = new JarFile("path_to_jar/shapeless_2.12-2.3.3.jar")
val entry = jar.getEntry("shapeless/Annotation.class")
val inStream = jar.getInputStream(entry)
As you mentioned scala.io.Source.fromResource works only within your project:
Source.fromResource("tstdir/source.txt")
Make sure the file is in the resources directory, like:
The way I found to achieve getting the path inside a jar depedency was creating a singleton (scala object) that has a method that loads the files. Since it is inside the Jar, the resulting path is relative to the jar itself. Here is the code :
object ClassLoaderTest {
def dockerFile: File =
new File(getClass.getClassLoader.getResource("docker/docker-compose.yml").getPath)
}
When called from a Trait (or an interface), the resulting path is :
jar:file:/home/myname/.ivy2/cache/com.mypackage/libraryname/jars/libraryname.libraryversion.jar!/docker/docker-compose.yml
I have a Scala script that I want to call from sbt. This Scala script refers to some dependencies. One of those dependencies uses a properties file. This properties file is provided by the run time as this dependency is run as a separate application.
Just to have the possibility to run that property-using dependency as a standalone, I wrote this Scala script that I want to call from sbt.
val fis = new FileInputStream("my.properties") // Fails here
val props = new Properties()
When I run the above code, it fails with an exception in my dependency where the properties file is loaded.
How to make this properties file available to the script under sbt?
Place the file my.properties in src/main/resources and use Source.fromURL(getClass.getResource("/my.properties")) instead (as it gives you more flexibility in where you can place the file on file systems as long as it's on CLASSPATH).
As a helper, use the following code to learn about the place where the file is expected when a "bare" File* types are in use:
println(new java.io.File("my.properties").getAbsolutePath)
Since the current working directory is the top-level directory of a project, the file is searched in $PROJECT_ROOT_DIR/my.properties.
I have directory structure like this
src
main
resources
text.txt
scala
hello
world.scala
test
same as main folder
pom.xml
When in IDE (Intellij10), I could access it with relative path ("src/main/resource/text.txt") but it seems I can not do that when I compile in jar. How to read that file ?
also, I found that test.txt is copy into root of jar. Is this normal behavior ? Since I fear this will be clash with other resources file in src/test/resources.
thanks
From http://www.java-forums.org/advanced-java/5356-text-image-files-within-jar-files.html -
Once the file is inside the jar, you cannot access it with standard FileReader streams since it is treated as a resource. You will need to use Class.getResourceAsStream().
The test.txt being copied into the root is not normal behavior and is probably a setting with your IDE.
8 years later, I am also facing the same question. To ease the life of future developers, here is the answer:
Being copied into the root is normal behaviour, as:
the resources folder is like a src folder and so the content is
copied, not the folder itself.
Now concerning the how-to question:
import scala.io.Source
val name = "text.txt"
val source: Source = Source.fromInputStream(getClass.getClassLoader.getResourceAsStream(name))
// Add the new line character as a separator as by getLines removes it
val resourceAsString: String = source.getLines.mkString("\n")
// Don't forget to close
source.close
I recently decided to use SBT to build an existing project.
In this project I have some .glsl files within the scala packages which I need to copy during the compilation phase.
The project is structured like this :
- myapp.opengl
- Shader.scala
- myapp.opengl.shaders
- vertex_shader.glsl
- fragment_shader.glsl
Is this file structure correct for SBT or do I need to put the .glsl files into an other directory. And do you know a clean way to copy these files into the target folder ?
I would prefer not putting these files into the resources directory since they are (non-compiled) sources files
Thanks
I would not recommend putting those files into src/main/scala as they do not belong there. If you want to keep them separate from your resource files, you can put them in a custom path, e.g. src/main/glsl and add the following lines to your project definition to have them copied into output directory:
val shaderSourcePath = "src"/"main"/"glsl"
// use shaderSourcePath as root path, so directory structure is
// correctly preserved (relative to the source path)
def shaderSources = (shaderSourcePath ##) ** "*.glsl"
override def mainResources = super.mainResources +++ shaderSources