Reading text file works in IDE but not in .jar

I am using 

File file = new File("res/movies.txt");

to read text from a bundled .txt file. My code works perfectly when running the program within IntelliJ IDEA, but when I create a .jar file and run it, it gives a "File not found" error. What can I do to make the code work both in the IDE as well as in the jar file?

Jon Skeet
people
quotationmark

You need to load the file as a resource. You can use Class.getResourceAsStream or ClassLoader.getResourceAsStream; each will give return an InputStream for the resource.

Once you've got an InputStream, wrap it in an InputStreamReader (specifying the appropriate encoding) to read text from it.

If you need to sometimes read from an arbitrary file and sometimes read from a resource, it's probably best to use separate paths to either create a FileInputStream for the file or one of the methods above for a resource, then do everything else the same way after that.

Here's an example which prints each line from resources/names.txt which should be bundled in the same jar file as the code:

package example;

import java.io.*;
import java.nio.charset.*;

public class Test {
    public static void main(String[] args) throws IOException {
        try (BufferedReader reader = new BufferedReader(
            new InputStreamReader(
                Test.class.getResourceAsStream("/resources/names.txt"),
                StandardCharsets.UTF_8))) {
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        }
    }
}

people

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