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import java.io.*;
import javax.swing.JFileChooser;
/** This program consists of one class with three methods and intends to use proper JavaDoc multiple line headers
* while allowing a user to choose a file of which the numbers will be
* averaged and the number of lines and mean will be displayed on the console.
*
* @author Cathy Ealy
*
*/
public class Week05 {
static int n;
//Declared a global int variable named “n” outside main
public static void main(String[] args) throws IOException {
JFileChooser jf = new JFileChooser();
int returnCode = jf.showDialog(null, null);
if (returnCode != JFileChooser.APPROVE_OPTION);{
System.exit(1);
//opens open dialog box for open file choice. Uses Chooser to allow the user to select a file.
}
String r;
r = jf.getSelectedFile().toString();//Saves the result of chooser in a string
//opens the dialog box so you can choose the file of which you want to open
double mean;
mean = calculateMean (r); //passes string into a method called calculateMean
displayResult (mean,n);
}
/**a method called calculateMean will:
1. Open the file, and read all the lines in the file (counting them as it goes, keeping the count in the global variable “n”):
2. Assume that each line of the file contains a number in a format that Double.parseDouble can handle. Use Double.parseDouble to convert each line of the file into a number
3. Add the value read from each line into a variable (initialized to zero, we call this type of variable an accumulator.)*/
public static double calculateMean(String r) throws IOException{
FileReader fr = new FileReader (r);
BufferedReader br = new BufferedReader (fr);
double sum = 0;
boolean repeat = true;
while (repeat){
String x;
x = br.readLine();
if (x != null){
double y;
y = Double.parseDouble (x);
sum = sum + y;
n = n+1;
}
else{
repeat = false;
}
}
br.close();
double mean;
mean = sum/n;
return mean;
}
/**a method called “displayResult”. (double, int) will:
1. display the mean on the console, with a string so that the user realizes that the mean is the mean.
2. Display the number of lines on the console, again, properly labeled. */
private static void displayResult(double mean, int n) {
System.out.println("The average was:" + " " + mean);
System.out.println("There were" + n + "lines in the file.");
}
}
MultiQuote
and to be honest I have never come across it before. I tried to Google around for a bit and I noticed that a similar thread on 
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