Accessing a txt file in the src folder

Question

I just need to access a txt file. My File object constructor cannot find a txt file I had already created and placed in the src folder. I want to avoid typing in the entire file path, as this project will be used between multiple computers where writing a file path starting back at the local drive will not work. The given image shows the situation. The left has my file paths, the bottom has the specific error message, and the center holds my code u to this point.

Frankly, I am just looking for what to put in the File constructor and not change code outside of it. However, any and all help would be appreciated.

https://i.stack.imgur.com/GoNgZ.png

Is this text file supposed to be a (read-only) resource, or an (read-write) external file? — Slaw, Sep 28 '21 at 05:27
@FoxVocs if you want to read and write to a file do not keep it inside your application. Keep I an external folder where the user executing the application has read and write permission. — seenukarthi, Sep 28 '21 at 05:54

julien.giband · Accepted Answer · 2021-10-07T14:14:26.860

As you wish to be able to read/write to this file, you should keep it external from your code. This means that your BufferedReader will have to be created from a filesystem path. Now there are several ways you could that, but you should preferably use java.nio API rather than the older java.io.File.

I can see mainly 3 scenarios here:

Use a relative path from working directory ., that is your project's location (NOT src) when debuging from IDE, or right next to your jar once it has been made:

try (BufferedReader br = Files.newBufferedReader(Paths.get("./test.txt"), StandardCharsets.UTF_8)) {
  //Do your stuff
}

Or if your file's in [projectDir]/pingus (still NOT src)

try (BufferedReader br = Files.newBufferedReader(Paths.get("./pingus/test.txt"), StandardCharsets.UTF_8)) {
  //Do your stuff
}

Note it will depend on where your application was launched from, but it's generally fine.

Use an absolute path generated from your code's storage location:

package pingus;
import java.io.BufferedReader;
import java.io.IOException;
import java.net.URISyntaxException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Pongus {

  public static void main(String[] args) throws URISyntaxException, IOException {
    //Find codebase directory
    Path codebase = Paths.get(Pongus.class.getProtectionDomain().getCodeSource().getLocation().toURI());
    Path absdir = codebase.getParent().normalize().toAbsolutePath();
    System.out.println("Working from " + absdir);
    //Path to your file
    Path txtFilePath = absdir.resolve("pingus/test.txt");
    System.out.println("File path " + txtFilePath);
    //Read
    try (BufferedReader rdr = Files.newBufferedReader(txtFilePath, StandardCharsets.UTF_8)) {
      System.out.println("Printing first line:");
      System.out.println("\t" + rdr.readLine());
    }
  }

}

Note this will definitely work when running from a jar. It will work during debugging using Eclipse in its default configuration, as codebase will initially point to the bin sub-folder in your project's path. It might not work with other IDE configurations where your compiled class can be stored elsewhere

Use an absolute path on your filesystem, either hard-coded or from some configuration.

try (BufferedReader rdr = Files.newBufferedReader(Paths.get("C:\\mydirs\\pingus\\test.txt"), StandardCharsets.UTF_8)) {
  //Do your stuff
}

score 0 · Answer 2 · answered Sep 28 '21 at 05:39

The way you want to do this is to keep the file in src/main/resources folder and use ClassPathResource class to find it. It's already answered here

Basically just replace line 10 with this to get your file (Credits to the poster):

  Resource resource = new ClassPathResource("jsonSchema.json");
  FileInputStream file = new FileInputStream(resource.getFile());

Extra: If you want to share files in test folders, put the files in src/test/resources instead

Accessing a txt file in the src folder

2 Answers2