Validating that a file exists

[Jacob Sousie]

Hey everyone!  me and my friend are writing a program that reads test scores form a file, prints them, and then averages them out and prints that.  

So we have it working, but we want to add something.

We want to make it that if the user inputs a invalid file path they will get an error and then asked to write a valid one without running the program again.  

Here's our code so far:

import java.util.Scanner;
import javax.swing.JOptionPane;
import java.io.*;

public class DGrade {

	public static void main(String[] args) throws IOException {

		String filename;
		filename = JOptionPane.showInputDialog("Please enter the file path.");
		File grades = new File(filename);
		Scanner scores = new Scanner(grades);
		
		
		int testscore = scores.nextInt();
		int testscore2 = scores.nextInt();
		int testscore3 = scores.nextInt();
		int testscore4 = scores.nextInt();
		int testscore5 = scores.nextInt();
		displayHeader();

		determineGrade(testscore);
		determineGrade(testscore2);
		determineGrade(testscore3);
		determineGrade(testscore4);
		determineGrade(testscore5);
		calcAverage(testscore, testscore2, testscore3, testscore4, testscore5);

		scores.close();

	}

	public static void displayHeader() {
		System.out.println("Score\t\tLetter Grade\n------\t\t-----------");
	}

	public static void determineGrade(double grade) {

		if (grade < 60)
			System.out.println(grade + "\t\t F");
		else if (grade < 70)
			System.out.println(grade + "\t\t D");
		else if (grade < 80)
			System.out.println(grade + "\t\t C");
		else if (grade < 90)
			System.out.println(grade + "\t\t B");
		else
			System.out.println(grade + "\t\t A");

	}

	// file path C:\Users\playe\Desktop\Java\Scores.txt
	public static void calcAverage(double testscore, double testscore2, double testscore3, double testscore4,
			double testscore5) {

		for (int i = 0; i <= 27; i++) {
			System.out.print("-");
			
		}
		System.out.println("\nAverage Score " + ((testscore + testscore2 + testscore3 + testscore4 + testscore5) / 5));
		
	

	}

}

Thanks in advance!

[Junilu Lacar]

Have you looked through the java.io.File API documentation?

[Jacob Sousie]

Junilu Lacar wrote:Have you looked through the java.io.File API documentation?

I Just did,  I'm new to Java and I don't understand a lot of those examples...lol

All I want to do is that if a user inputs something invalid or an invalid file path I could give them a message.

[Paul Clapham]

Jacob Sousie wrote:

Junilu Lacar wrote:Have you looked through the java.io.File API documentation?

I Just did,  I'm new to Java and I don't understand a lot of those examples...lol

The method you're looking for is named "exists()".