Water Billing SystemV3

/**
 *This application, Water Billing System, will figure out how much a customer pays based on a particular reading.
 * As well as creating or updating an account, they can also perform a search using it's feature.
 */


import java.util.Scanner;
import java.util.ArrayList; //arraylist stores data and uses non primitive data type


public class Defense_WaterBilling {   //class

    static ArrayList<String> name = new ArrayList<String> ();           //setting arraylist as a global varibale to access in the whole parts of the program
    static ArrayList<String> address = new ArrayList<String> ();
    static ArrayList<Double> prevMreading = new ArrayList<Double> ();   //Uses wrapper classes
    static ArrayList<Double> currMreading = new ArrayList<Double> ();
    static ArrayList<Double> Dues = new ArrayList<Double> ();
    static ArrayList<Double> consumption = new ArrayList<Double> ();
    static ArrayList<String> discount = new ArrayList<String> ();
    static Scanner scr = new Scanner(System.in);     // initializing the scanner as a global variable also

    public static void main(String[] args) {   //the main method includes the while loop for looping the main menu and uses switch statement

        int mainMenu = -5; //initialize mainMenu = -1
        while (mainMenu != 0) {   //while loop for looping the menu until the user press exit
            menu();  //calling the menu user defined method
            mainMenu = scr.nextInt(); //getting user choice
            scr.nextLine();
            switch (mainMenu) {
                case 0:
                         exit();
                         break;//calling the userdefined methods
                case 1:
                         add();
                         break;//calling the userdefined methods
                case 2:
                         update();
                         break;//calling the userdefined methods
                case 3:
                         display();
                         break;//calling the userdefined methods
                case 4:
                         search();
                         break;//calling the userdefined methods
                default: System.out.println("Out of range");
            }
        }
    }

        static void menu() {                   //the menu output
        System.out.println("-------[Water Billing System]-------");
        System.out.println("[1] Create a new user account.");
        System.out.println("[2] Update a current account");
        System.out.println("[3] Show accounts for all users.");
        System.out.println("[4] Try looking for an account here.");
        System.out.println("[0] Exit");
        System.out.print("Enter Your Choice: ");

    }

        static void add() {  //method to add data to the arraylist
        String Name, Address;
        double prev, curr,consumed, due, sub = 0.0;
        int rate;
            System.out.println("------Create a new user account!------");
            System.out.println("Name: ");
            Name = scr.nextLine();
            Defense_WaterBilling.name.add(Name); //insert the element to the arraylist
            System.out.println("Address: ");
            Address = scr.nextLine();             //getting String input from the user
            Defense_WaterBilling.address.add(Address); //insert the element to the arraylist
            System.out.println("Previous reading: ");
            prev = scr.nextDouble();             //getting input from the user
            prevMreading.add(prev);                   //insert the element to the arraylist
            System.out.println("Current reading: ");
            curr = scr.nextDouble();              //getting input from the user
            currMreading.add(curr);                 //insert the element to the arraylist
            System.out.println("[1] Residential");
            System.out.println("[2] Business");
        rate = scr.nextInt();                 //getting input from the user
        consumed = curr - prev;
        consumption.add(consumed);           //insert the element to the arraylist
        if (rate == 1) {                    //nested if to get the sub value
            if (consumed > 10) {
                sub = 200 + ((consumed - 10) * 30);
            }
            if (consumed <= 10) {
                sub = 200;
            }
        } else if (rate == 2) {
            if (consumed > 20) {
                sub = 500 + ((consumed - 20) * 50);
            }
            if (consumed <= 20) {
                sub = 500;
            }
        }
        int yearser;
        System.out.println("how many years in using the service?");
        yearser = scr.nextInt();         //getting input from the user
        if (yearser >= 15 ) {
            due = sub - (sub * .15);
            discount.add("15% promo discount applied!");
        } else {
            due = sub;
            discount.add("No promo discount appllied!");
        }
        Dues.add(due);   //insert the element to the arraylist
    }

        static void update() { //function will update name and address only
        String namess, newName, newAddress;
        System.out.println("------Update a current account------!");
        System.out.println("Enter the name of the current Account: ");
        namess = scr.nextLine();
        int position = 0; //initialize postion to 0 value
        boolean matched = false; //initialize matched to false value
        for (String profile : Defense_WaterBilling.name) {  // uses for each loop to get the element,The loop goes through each index of array name
            if (profile.contains(namess)) {  //check if the element is present in the array and exactly the same as the current index in names list
                matched = true;
                position = Defense_WaterBilling.name.indexOf(profile); // return the position of the element
                break;
            } else
            {
                matched = false;
                System.out.println("No data found !!!!!");
            }
        }
        if (matched == true)
        {
                    System.out.println("New name: ");
                    newName = scr.nextLine(); //getting the new name input from the user
                    Defense_WaterBilling.name.set(position, newName); // Set newName as new data for name and the index is equal to the value of position
                    System.out.println("New address: ");
                    newAddress = scr.nextLine(); //getting the new address input from the user
                    address.set(position, newAddress);
        }
    }

        static void display()
    {
        System.out.println("------Show accounts for all users!------");
        for (int i = 0; i < name.size(); i++)   //uses for loop
        {
            System.out.println("Name: " + name.get(i)); // i is the index of the array name
            System.out.println("Address: " + address.get(i)); //get, is a method in arraylist
            System.out.println("Previous reading: " + prevMreading.get(i));
            System.out.println("Current reading: " + currMreading.get(i));
            System.out.println("Current consumption: " + consumption.get(i));
            System.out.println("Total payment due: " + Dues.get(i));
            System.out.println("Promo: " + discount.get(i));
            System.out.println("");


        }
    }

        static void search()
    {
        int position = 0; //initialize postion to 0 value
        String names;
        boolean matched = false; //initialize matched to false value
        System.out.println("------Try looking for an account here!------");
                System.out.println("Name: ");
                names = scr.nextLine();
                for (String profile : Defense_WaterBilling.name) { // uses for each loop to run from index 0 to the last until matched == true
                    if (profile.contains(names)) //check if the element is present in the array and exactly the same as the current index in names list
                    {
                        matched = true; //change value matched to true
                        position = Defense_WaterBilling.name.indexOf(profile); //position = index where the profile is
                        break;
                    } else
                    {
                        matched = false; // if not matched keep to false
                         System.out.println("Not found!!!!!!!");
                    }
        }

        if (matched == true) {
            System.out.println("");
            System.out.println("Name: " + Defense_WaterBilling.name.get(position)); //print where the index of the searched element
             System.out.println("Address: " + Defense_WaterBilling.address.get(position));
              System.out.println("Previous reading: " + prevMreading.get(position));
               System.out.println("Current reading: " + currMreading.get(position));
                 System.out.println("Current consumption: " + consumption.get(position));
                  System.out.println("Total payment due: " + Dues.get(position));
                    System.out.println("Promo: " + discount.get(position));
                     System.out.println("");

        }
    }

        static int exit() { //exit method
        return 0;
    }

}