here's my code below and i cant seem to find out how to return to public static void main after selecting yes in the dialog box. this cud be a very damn question however i get confuse about how to resolve this. thanks. 
by the way, this program is still incomplete. iam just stuck with the dialog box to return to main (); Hope you could assist,thanks.
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package midterm_exercise_2;

import java.util.Iterator;
import java.util.List;
import javax.swing.*;

public class Main {

    public static void
            main(String[] args) {

         int m = Integer.parseInt(JOptionPane.showInputDialog("--MENU--\n\n"
                 + "[1] PreEmptive Scheduling Algorithm\n"
                 + "[2] Non-PreEmptive Scheduling Algorithm\n"
                 + "\nEnter Choice:"));
               
         if (m ==1){
             PreEmpt();
             YesNo();
         }
         else
             NonPreEmpt();



    }


  public static void YesNo(){

        System.out.printf("JOptionPane.YES_OPTION    = %d%n" +
                          "JOptionPane.NO_OPTION     = %d%n" +
                          "JOptionPane.CLOSED_OPTION = %d%n",
                           JOptionPane.YES_OPTION,
                           JOptionPane.NO_OPTION,
                           JOptionPane.CLOSED_OPTION);
        int more = JOptionPane.YES_OPTION;
        do {
            more = JOptionPane.showConfirmDialog(null, "Do you want to go back to Main Menu?", "Confirmation",
                                      JOptionPane.YES_NO_OPTION);
            System.out.println("more = " + Main ());
        } while(more == JOptionPane.YES_OPTION);

        
  }

  public static void PreEmpt() {

        int m = Integer.parseInt(JOptionPane.showInputDialog("--MENU--\n\n"
                + "[1] First Come - First Served\n"
                + "[2] Shortest Job First\n"
                + "[3] Priority Scheduling\n"
                + "Enter Choice:"));


        if (m == 1) {
            FCFS();
        } else if (m == 2) {
            SJF();
        } else if (m == 3) {
            P();
        } else {
            JOptionPane.showMessageDialog(null, "Error Message", "Error!", JOptionPane.ERROR_MESSAGE);
        }
    }


  public static void NonPreEmpt() {

        int m = Integer.parseInt(JOptionPane.showInputDialog("--MENU--\n\n"
                + "[1] First Come - First Served\n"
                + "[2] Shortest Job First\n"
                + "[3] Priority Scheduling\n"
                + "Enter Choice:"));


        if (m == 1) {
            FCFS();
        } else if (m == 2) {
            SJF();
        } else if (m == 3) {
            P();
        } else {
            JOptionPane.showMessageDialog(null, "Error Message", "Error!", JOptionPane.ERROR_MESSAGE);
        }
    }

//FIRST COME FIRST SERVED SCHEDULING
    public static void FCFS() {

        int bt[] = new int[4], wt[] = new int[4], twt = 0, awt, num;
        String output1[] = new String[10];

        for (num = 0; num <= 3; num++) {
            bt[num] = Integer.parseInt(JOptionPane.showInputDialog("\nEnter Burst time for P" + (num + 1) + " : "));
        }

        for (num = 0; num <= 3; num++) {
            if (num == 0) {
                wt[num] = 0;
            } else {
                wt[num] = wt[num - 1] + bt[num - 1];
                output1[num] = "\nWaiting time for P" + (num + 1) + " = " + wt[num];
            }
        }

        for (num = 0; num <= 3; num++) {
            twt += wt[num];
        }
        awt = twt / 4;

        JOptionPane.showMessageDialog(null, output1, "FCFS", JOptionPane.INFORMATION_MESSAGE);
        JOptionPane.showMessageDialog(null, "\nAverage Waiting Time =" + awt, "FCFS", JOptionPane.INFORMATION_MESSAGE);
    
        
    }

//SHOTEST JOB FIRST
    public static void SJF() {

        int bt[] = new int[4], wt[] = new int[4], twt = 0, awt, x, num, temp = 0, p[] = new int[4];
        boolean found = false;
        String output1[] = new String[10];

        for (num = 0; num <= 3; num++) {
            bt[num] = Integer.parseInt(JOptionPane.showInputDialog("\nEnter Burst time for P" + (num + 1) + " : "));
        }

        for (num = 0; num <= 3; num++) {
            p[num] = bt[num];
        }

        for (x = 0; x <= 2; x++) {
            for (num = 0; num <= 2; num++) {
                if (p[num] > p[num + 1]) {
                    temp = p[num];
                    p[num] = p[num + 1];
                    p[num + 1] = temp;
                }
            }
        }

        for (num = 0; num <= 3; num++) {
            if (num == 0) {
                for (x = 0; x <= 3; x++) {
                    if (p[num] == bt[x] && found == false) {
                        wt[num] = 0;
                        output1[num] = "\nWaiting time for P" + (num + 1) + " = " + wt[num];
                    }
                }
            } else {
                for (x = 0; x <= 3; x++) {
                    if (p[num] == bt[x] && found == false) {
                        wt[num] = wt[num - 1] + p[num - 1];
                        output1[num] = "\nWaiting time for P" + (num + 1) + " = " + wt[num];
                    }
                }
            }
        }

        for (num = 0; num <= 3; num++) {
            twt += wt[num];
        }

        awt = twt / 4;

        JOptionPane.showMessageDialog(null, output1, "SJF", JOptionPane.INFORMATION_MESSAGE);
        JOptionPane.showMessageDialog(null, "\n\nAverage waiting time: " + awt, "SJF", JOptionPane.INFORMATION_MESSAGE);
    }

//Priority Scheduling
    public static void P() {

        int bp[] = new int[4], wtp[] = new int[5], p[] = new int[4], sp[] = new int[4], twt = 0, awt, num, x, temp = 0;
        boolean found = false;

        String output1[]=new String[10];

        for (num = 0; num <= 3; num++) {
            bp[num] = Integer.parseInt(JOptionPane.showInputDialog("\nEnter Burst time for P" + (num + 1) + " : "));

        }

        for (num = 0; num <= 3; num++) {
            p[num] = Integer.parseInt(JOptionPane.showInputDialog("\nEnter Priority for P" + (num + 1) + " : "));

        }

        for (num = 0; num <= 3; num++) {
            sp[num] = p[num];
        }

        for (x = 0; x <= 2; x++) {
            for (num = 0; num <= 2; num++) {
                if (sp[num] > sp[num + 1]) {
                    temp = sp[num];
                    sp[num] = sp[num + 1];
                    sp[num + 1] = temp;
                }
            }
        }

        for (num = 0; num <= 3; num++) {
            if (num == 0) {
                for (x = 0; x <= 3; x++) {
                    if (sp[num] == p[x] && found == false) {
                        wtp[num] = 0;
                        output1[num] = "\nWaiting time for P" + (x + 1) + " = " + wtp[num];
                        temp=x;
                        p[x]=0;
                        found = true;
                    }
                }
                found = false;
            } else {
                for (x = 0; x <= 3; x++) {
                    if (sp[num] == p[x] && found == false) {
                        wtp[num] = wtp[num - 1] + bp[temp];
                        output1[num] = "\nWaiting time for P" + (x + 1) + " = " + wtp[num];
                        temp = x;
                        p[x] = 0;
                        found = true;
                    }
                }
                found = false;
            }
        }

        for (num = 0; num <= 3; num++) {
            twt = twt + wtp[num];
        }

        JOptionPane.showMessageDialog(null, output1, "Priority", JOptionPane.INFORMATION_MESSAGE);
        JOptionPane.showMessageDialog(null, "\n\nAverage waiting time: " + (awt = twt / 5), "Priority", JOptionPane.INFORMATION_MESSAGE);
    }

   

}

Here is an example of how to create a simple menu. You can put that in a method and call it. You can have different menus in different methods. And you can have those methods called from another menu-method:

void menu_1 () {

int choice = 0;
while (true) {
  // print the menu
  //get the input
  
  choice = ...;

  if (choice==1) {
    // do something
  } else if (choice==2) {
    //
  } .... else if (choice==4) {
    // exit the loop
    break;
  } else {
     System.out.println("Invalid choice");
  } 
}

}

You should make the necessary changes for your case.

And you can have 1 method with the main menu: PreEmptive / Non-PreEmptive

And 2 others with menus for PreEmptive and Non-PreEmptive

In the method with the main menu, at the ifs with the choices you can call the other menus:

if (choice==1) {
    // call menu of PreEmptive (different method with its own menu)
  } else if (choice==2) {
    // call menu of Non - PreEmptive (different method with its own menu)
  } .... else if (choice==3) {
    // exit the loop
    break;
  } else {
     System.out.println("Invalid choice");
  }

If you want to get some return values then you need to change "void" in methods you calling for whatever return type you need boolean/int/string/etc.

@javaAddict you been 1 second faster LOL

Edited 5 Years Ago by peter_budo: n/a

This question has already been answered. Start a new discussion instead.