What's wrong with this code in java that uses FileReader?

Question

I have been trying to learn about FileReader and hence wanted to test it out. I created a class whose constructor takes in a string(name of the file) and creates a file and then reads from it and then prints the first character out, but my code is not working and is showing errors. This is my java code.

package test_3;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class Files {
    public Files(String s) throws FileNotFoundException, IOException{
        File f = new File(s);
        FileReader fr = new FileReader(f);
        System.out.println(fr.read());
    }

    public static void main(String args[]) throws FileNotFoundException,   IOException{
        Files myFile = new Files("input.txt");
    }
}

This is the error information

Exception in thread "main" java.io.FileNotFoundException: input.txt (The system cannot find the file specified)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(Unknown Source)
    at java.io.FileInputStream.<init>(Unknown Source)
    at java.io.FileReader.<init>(Unknown Source)
    at test_3.Files.<init>(Files.java:11)
    at test_3.Files.main(Files.java:16)

Answer 1

Because the file cannot be found. What you should do is get the path to where java is looking for the file, like so.

System.out.print(System.getProperty("user.dir"));

And then place "input.txt" within that directory (the directory that is printed when that code is ran).

Alternatively, use the full absolute path to input.txt