I want my graphical user interface to accept an integer

Question

Hello I'm having trouble with my work. I want a graphical user interface to accpet a single statement in the form "insert name number" .

For example of such a command is " insert Whiz 105 "

I've programed Java to use "insert" word in the user input and also string. However I don't know how to make Java detect both string and integer in one statement.

How do I create a statement that allows me to separate String and Integers, when user enters both them in the GUI?. For example instead of creating a two inputs for String and Integers, I use one input instead to refer to both of them.

Here is my code, please base your answers to it.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

/**
   This class is used to demonstrate
   the operations in the LinkedList1 class.
*/

public class LinkedList1Demo extends JFrame
{    
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private LinkedList<String> names;


    private JTextArea  listView;
    private JTextField cmdTextField;
    private JTextField resultTextField;

    public LinkedList1Demo()
    {
       names = new LinkedList<String>(); 
       listView = new JTextArea();
       cmdTextField = new JTextField();
       resultTextField = new JTextField();       

       // Create a panel and label for result field
       JPanel resultPanel = new JPanel(new GridLayout(1,2));
       resultPanel.add(new JLabel("Command Result"));
       resultPanel.add(resultTextField);
       resultTextField.setEditable(false);
       add(resultPanel, BorderLayout.PAGE_START);

       // Put the textArea in the center of the frame
       add(listView);
       listView.setEditable(false);
       listView.setBackground(Color.WHITE);
       listView.setPreferredSize(new Dimension(200, 25));



       // Create a panel and label for the command text field
       JPanel cmdPanel = new JPanel(new GridLayout(1,2));
       cmdPanel.add(new JLabel("Command Name:"));
       cmdPanel.add(cmdTextField);
       add(cmdPanel, BorderLayout.PAGE_END);  
       cmdTextField.addActionListener(new CmdTextListener());
       cmdPanel.setPreferredSize(new Dimension(200, 25));

       // Set up the frame
       setTitle("Linked List Demo");
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       pack();
       setVisible(true);       
    }

    /**
       Private class that responds to the command that 
       the user types into the command entry text field.
    */

    private class CmdTextListener
            implements ActionListener
    {            
        public void actionPerformed(ActionEvent evt)
        {
            String cmdText = cmdTextField.getText();

            Scanner sc = new Scanner(cmdText);

            String cmd = sc.next();

            if (cmd.equals("insert"))
            {
                if (sc.hasNextInt())
                {
                    // add index element
                    int index = sc.nextInt();
                    String element = sc.next();
                    names.add(index, element);                
                }
                else
                {  
                    // add element
                    String element = sc.next();
                    names.add(element);                
                }
                listView.setText(names.toString());
                pack();
                return;
            }
            if (cmd.equals("remove"))
            {
                if (sc.hasNextInt())
                {
                    // remove index
                    int index = sc.nextInt();
                    Object obj = names.remove(index);
                    String res = obj.toString();
                    resultTextField.setText(res);              
                }
                else
                {
                    // remove element
                    String element = sc.next();
                    boolean res = names.remove(element);
                          String resText = String.valueOf(res);
                    resultTextField.setText(resText);
                }
                listView.setText(names.toString());
                pack();
                return;
            }
            if (cmd.equals("isempty"))
            {
                    String resText = String.valueOf(names.isEmpty());
                resultTextField.setText(resText);
                return;
            }
            if (cmd.equals("size"))
            {
                   String resText = String.valueOf(names.size());
               resultTextField.setText(resText);
               return;
            }

        }
    }

    /**
       The main method creates an instance of the 
       LinkedList1Demo class which causes it to 
       display its window.
    */

    public static void main(String [ ] args)
    {
        new LinkedList1Demo();

    }

}

Answer 1

I'd ask you to explain your requirement better. But a quick idea if you're sure you'll only get a bunch of strings and one integer, would be to separate the string by using a tokenizer or, preferably, the split method.

Then you iterate through each individual word and try with the "Integer.parseInt()" method. If a NumberFormatException raises, it's a string and you should append it to your string object. Otherwise, it's an integer and you can threat it as so.

Answer 2

Use the String method split to split the String.

String input = /* pull from the text box */.
String[] tokens = input.split("\\s");
if (tokens.length == 3)
{
     String command = tokens[0];
     String intValue= tokens[2];
}

Answer 3

You can try something like:

String cmd = sc.next();

try {

    int number = Integer.parseInt(cmd);

} catch (NumberFormatException e) {
     if (cmd.equals("insert"))
            {
                if (sc.hasNextInt())
                {
                    // add index element
                    int index = sc.nextInt();
                    String element = sc.next();
                    names.add(index, element);                
                }
                else
                {  
                    // add element
                    String element = sc.next();
                    names.add(element);                
                }
                listView.setText(names.toString());
                pack();
                return;
            }
            if (cmd.equals("remove"))
            {
                if (sc.hasNextInt())
                {
                    // remove index
                    int index = sc.nextInt();
                    Object obj = names.remove(index);
                    String res = obj.toString();
                    resultTextField.setText(res);              
                }
                else
                {
                    // remove element
                    String element = sc.next();
                    boolean res = names.remove(element);
                          String resText = String.valueOf(res);
                    resultTextField.setText(resText);
                }
                listView.setText(names.toString());
                pack();
                return;
            }
            if (cmd.equals("isempty"))
            {
                    String resText = String.valueOf(names.isEmpty());
                resultTextField.setText(resText);
                return;
            }
            if (cmd.equals("size"))
            {
                   String resText = String.valueOf(names.size());
               resultTextField.setText(resText);
               return;
            }
}

This will attempt to parse the input to an integer. If it is a number then it will succeed otherwise it will fail and enter your catch block and be processed as a string.