File exists but program throws a FileNotFoundException - try-catch

Question

/*
*This program checks type casting from String to int/double from a file
*/
import java.io.*;
import java.lang.String;
public class ConvertingStringsToNums {
public static void main (String[] args){
File dataFile = new File("/files/scores.dat");
FileReader in;
BufferedReader readFile;
String score;
double avgScore, totalScores = 0;
int numScores = 0;
//------------------------------------------------------------
try {
in = new FileReader(dataFile);
readFile = new BufferedReader(in);
while((score = readFile.readLine()) != null) {
numScores += 1;
System.out.println(score);
totalScores += Double.parseDouble(score);
}
avgScore = totalScores / numScores;
readFile.close();
in.close();
} catch(FileNotFoundException e) {
System.err.println("FileNotFoundException: " + e.getMessage());
} catch (IOException e) {
System.err.println("IOException: " + e.getMessage());
} //end try/catch
}
}

Answer 1

1) If you wish to open a file at an absolute file path on your hard drive:
br = new BufferedReader (
new FileReader(
new File ("/files/scores.dat")));
2) If you wish to open a file at an relative path relative to where you started your app:
br = new BufferedReader (
new FileReader(
new File ("files/scores.dat")));
3) If you wish to open a file at an relative path relative to your class files (particularly relevant for packages and/or for executing from a .jar or a .war):
this.getClass().getResourceAsStream ("files/scores.dat");
'Hope that helps

Answer 2

The reason is can be that you wont be having permission to open the file.
try chmod 755 scores.dat from terminal in order to change the permissions and see if the error still exist.

Answer 3

The answer to this problem exists in the javadocs for the File class:
For UNIX platforms, the prefix of an absolute pathname is always "/". Relative pathnames have no prefix. The abstract pathname denoting the root directory has the prefix "/" and an empty name sequence.
In your code, you have the following:
File dataFile = new File("/files/scores.dat");
According to the documentation, this is an absolute path, which means Java is looking for a folder at the root of the filesystem called "files" and then looking for scores.dat in that folder.
If you instead expect to search for a files directory that is relative to the current directory, you'd need to omit the first /:
File dataFile = new File("files/scores.dat");
The other option is to use an absolute path to your data file, but you may run into problems if you change the location of your project or put the class files in a JAR file.
Try turning up your logging level to DEBUG or ALL so that you can see exactly where the program is trying to look. This will help you adjust your code to target the right folder.