Missing return statement

package trianglecalculation;

import java.text.*;
import java.io.*;
import java.util.*;
 /* This class uses ArrayList of triangular objects to
    calculate their total area and perimeter.
*/
public class Main
{

    /* this method is used to read in the object sides,
    it needs additional validation */
    public static double input (BufferedReader r, String prompt) throws
IOException
    {
        double side=0.0;

        // handle the exceptions
        try {
            System.out.print( "Please enter " + prompt);
            String myString = r.readLine();
            side = Double.parseDouble(myString);
            }

        catch (NumberFormatException nfe)
                {
                    System.out.println("Please enter a number!\n" + nfe);
                }
        return side;
    } // end of input()

public static double main(String[] args) throws IOException // Array list
will be used instead of array?!
    {
        ArrayList aList = new ArrayList(); // Created with default size
(10).
        Triangle ob = new Triangle(); // will be used as work object

        int choice = 0; // for the user choice
        double side1, side2, side3;
        boolean exceptThrown = false; // if exception is thrown
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);

        do {
                try {
                        System.out.print(" Please choose a triangular
object to add: ");
                        System.out.println( " 1: General; 2: Equilateral;
3: Right; 0: None ");
                        String myString = br.readLine(); //reads a line
(string) from the buffer br
                        //Parses the string argument
                        choice = Integer.parseInt(myString);
                    }

                catch (NumberFormatException nfe)
                    {
                        exceptThrown = true;
                        System.out.println( "Please enter a number!\n" +
nfe);
                    }

                switch (choice)
                {
                  case 1: side1 = input(br, "side1: " );
                      side2 = input (br, "side2: " );
                      side3 = input (br, "side3: " );
                      Triangle tri = new Triangle(side1, side2, side3);
                      aList.add((Object) tri); //add to the list
                      break;

                  case 2: side1 = input(br, "side: ");
                        EquilateralTriangle equi = new
EquilateralTriangle(side1);
                        aList.add((Object) equi); //add to the list
                        break;

                  case 3: side1 = input(br, "side1: ");
                      side2 = input (br, "side2: ");
                      RightTriangle rig = new RightTriangle(side1,
side2);
                      aList.add((Object) rig); //add to the list
                      break;

                  case 0: break;
                    default: System.out.println( "\n Wrong choice!" );
                    exceptThrown = true;
                }

            } while (choice != 0 && !exceptThrown); //repeat the input

        if (!exceptThrown) // will skip, if an exception was thrown
            {
                double totalA, totalP; // for the total area and
perimeter
                System.out.println("\nObjects \t\t\t area \t\t
perimeter:");
                // To accumulate the total area and perimeter
                totalA = totalP =0.0;
                /* In this loop each object from the array list will be
extracted and its name, area, and perimeter printed out. */

                for(int i = 0; i < aList.size(); i++)
                    {
                        ob = (Triangle)aList.get(i); //casting to
Triangle
                        System.out.print (ob.displayName());
                        System.out.print ( "\t--> " + ob.area());
                        System.out.println ( " \t: " + ob.perimeter());
                        totalA += ob.area();
                        totalP += ob.perimeter();
                    }

                /* if you would like to specify the number of fraction
digits,
                  use the NumberFormat abstract class. */
                  NumberFormat nf; // this is not an object
                 //Returns a general-purpose number format for the current
default locale
                  nf = NumberFormat.getNumberInstance();
                  nf.setMaximumFractionDigits(3); // to specify the number
of fraction digits

                 String areaTotal = nf.format(totalA); // convert to
String
                 String perimTotal = nf.format(totalP);
                 System.out.print("\nTotal area and perimeter are:");
                 System.out.println("\t\t" +areaTotal+ " :
"+perimTotal);

            } // end if

     } // end main - here it says there is a missing return statement
} // end class

I don't need there to be an else, nor do I need an "=" within the if, so
any ideas what I can do to fix this?