Get user input and find file and read it.....argh

Question

Ok, so I have to write a program that asks a user for the name of the file they want opened and then it is to read it and then display the max score and the minimum score on the file. also to display the average score on the file. Along with that it is supposed to display how many As, Bs, Cs, Ds, and Fs were on the file IE: a: 1 b: 3 c: 0 d: 4 f: 1. etc.
Also, the next part is to have the program open the input file and then write all the information to an output file. I was able to do this and have the output file show the peoples names and their score along wtih their grade adn then the whole score average at the end of the output file....
My question is how do I do the first part by asking the user for the name of file and then for the program to find the file and then display the max, min, average and how many letter grades the class got?

Answer 1

this is what i have so far and the code before didnt work with JCreator, came up with lots of errors......
What do i have to do to get the max value and min value to display along with the amount of As, Bs, Cs, Ds, and Fs????
import java.io.*;
class extest
public static void main(String [] args) throws IOException
// First, open the input file
TextReader filein = new TextReader(new FileInputStream("test.txt"));
// Read our number
int x;
x = filein.readInt();
String [] first=new String[x];
String [] last=new String[x];
int [] score=new int[x];
// load data from the input file test1.txt
for (int i=0; i<x; i++)
first=filein.readWord();
last[i]=filein.readWord();
score[i]=filein.readInt();
     WriteTestFile(first, last, score, x);
public static void WriteTestFile(String f[], String last[], int score[], int x)
double average=0;
// Next, open the output file
try
PrintWriter fileout = new PrintWriter(
new FileWriter("grade.txt") );
// OK, now write to the file
fileout.println(x);
for (int i=0; i<x; i++)
average=average+score[i];
if (score[i]>90)
fileout.println(f[i]+" "+last[i]+" " + score[i] +": "+"A");
else if (score[i]>80)
fileout.println(f[i]+" "+last[i]+ " " + score[i] + ": "+"B");
else if (score[i]>70)
fileout.println(f[i]+" "+last[i]+ " " +score[i] + ": "+"C");
else if (score[i]>60)
fileout.println(f[i]+" "+last[i]+ " " +score[i] + ": "+"D");
else
fileout.println(f[i]+" "+last[i]+" " +score[i] + ": "+"F");
fileout.println("The average score of the class is "+average/x);
// we're done with the output file
fileout.close();
catch (IOException e)
throw new RuntimeException(e.toString());
System.out.println("***** Welcome to the Grade Program! *****");
     System.out.println("");
     System.out.println("Please enter the name of the file you want to open: ");
     TextReader input = new TextReader(System.in);
     String fileName = input.readLine();
System.out.println("The average of the scores is: "+average/x);
System.out.println("The maximum score is: ");
System.out.println("The minimum score is: ");
System.out.println("Number of scores by letter grade:");
System.out.println("A: ");
System.out.println("B: ");
System.out.println("C: ");
System.out.println("D: ");
System.out.println("F: ");