IMPORTANT. DO: Unfinished Lab

package Java;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.Scanner;

import javax.swing.*;


public class Lab {

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

		PrintWriter waterbill = new PrintWriter("cust.txt");
		PrintWriter usage = new PrintWriter("custbill.txt");

		String lastname = JOptionPane.showInputDialog("Enter last name");
		String address = JOptionPane.showInputDialog("Enter Address");

		int prevusage = Integer.parseInt (JOptionPane.showInputDialog("Enter previous month's usage"));
		double currusage = Double.parseDouble (JOptionPane.showInputDialog("Enter current month's usage"));


		waterbill.println(lastname + " " + address + " " + prevusage + " " + currusage);
		waterbill.close();

		Scanner infile = new Scanner (new FileReader("cust.txt"));
		String fname, faddress;
		int fprevusage;
		double fcurrusage;

		 fname = infile.next();
		 faddress = infile.next();
		 fprevusage = infile.nextInt();
		 fcurrusage = infile.nextDouble();

		double usagecalc = fcurrusage - fprevusage;

		JOptionPane.showMessageDialog (null, "The total usage is " +usagecalc);

		if (faddress.equalsIgnoreCase("Maa"))
		{
			double costperunit = 4.5;

		}

		else if (faddress=="Buhangin")
		{
			double costperunit = 5.00;
		}
		else if (faddress =="Sasa")
		{
			double costperunit = 3.50;
		}
		else {
			double costperunit = 2.00;
		}

		usage.println(usagecalc);


		usage.close();


		// Incomplete / DO: if else, determine the cost per unit depending on address and calculate billing (billing = usage * costperunit)

		// Costperunit value
		// Maa = 4.50 / Buhangin = 5.00 / Sasa = 3.50 / any others = 2.00

		// DO: Using printwriter, write the following to custbill.txt == <lastname> <address> <usage> <billing>

	}

}