work

// OddEven.java
import javax.swing.JOptionPane;

public class OddEven {
    /**
     * "input" is the number that the user gives to the computer
     */
    private int input; // a whole number("int" means integer)

    /**
     * This is the constructor method. It gets called when an object of the OddEven type
     * is being created.
     */
    public OddEven() {
    /*
     * In most Java programs constructors can initialize objects with default values, or create
     * other objects that this object might use to perform its functions. In some Java programs, the
     * constructor may simply be an empty function if nothing needs to be initialized prior to the
     * functioning of the object.  In this program's case, an empty constructor would suffice, even if
     * it is empty. A constructor must exist, however if the user doesn't put one in then the compiler
     * will create an empty one.
     */
    }

    /**
     * This is the main method. It gets called when this class is run through a Java interpreter.
     * @param args command line arguments (unused)
     */
    public static void main(final String[] args) {
        /*
         * This line of code creates a new instance of this class called "number" (also known as an
         * Object) and initializes it by calling the constructor.  The next line of code calls
         * the "showDialog()" method, which brings up a prompt to ask you for a number
         */
        OddEven number = new OddEven();
        number.showDialog();
    }

    public void showDialog() {
        /*
         * "try" makes sure nothing goes wrong. If something does,
         * the interpreter skips to "catch" to see what it should do.
         */
        try {
            /*
             * The code below brings up a JOptionPane, which is a dialog box
             * The String returned by the "showInputDialog()" method is converted into
             * an integer, making the program treat it as a number instead of a word.
             * After that, this method calls a second method, calculate() that will
             * display either "Even" or "Odd."
             */
            this.input = Integer.parseInt(JOptionPane.showInputDialog("Please Enter A Number"));
            this.calculate();
        } catch (final NumberFormatException e) {
            /*
             * Getting in the catch block means that there was a problem with the format of
             * the number. Probably some letters were typed in instead of a number.
             */
            System.err.println("ERROR: Invalid input. Please type in a numerical value.");
        }
    }

    /**
     * When this gets called, it sends a message to the interpreter.
     * The interpreter usually shows it on the command prompt (For Windows users)
     * or the terminal (For *nix users).(Assuming it's open)
     */
    private void calculate() {
        if ((this.input % 2) == 0) {
            JOptionPane.showMessageDialog(null, "Even");
        } else {
            JOptionPane.showMessageDialog(null, "Odd");
        }
    }
}

 ___________________________________________________________________


 // Hello.java
import java.io.*;
import javax.servlet.*;

public class Hello extends GenericServlet
{
    public void service(final ServletRequest request,final ServletResponse response)
            throws ServletException, IOException
     {
       response.setContentType("text/html");
       final PrintWriter pw = response.getWriter();
       try {
           pw.println("Hello, world!");
       } finally {
           pw.close();
       }
   }
}