Spiffy Program Running Software

Question

I am currently just fooling around trying to catch up on my Java. I created this little program that when you type something in it then loads up the program. I was wondering if anyone could tell me what was wrong with it, and tell me how to change it to an "exe" file so that I could run it off of my desktop.
Here is the Code:
import javax.swing.JOptionPane;
class runprogram {
     public static void main(String args[])  {
     JOptionPane.showInputDialog
                   ^----not a statement
        ("Input Command");
    if{
    else     (response.equals("RUN NOTEPAD"))
        Runtime.getRuntime().exec("notepad.exe");
    else
    if  (response.equals("null"))
         ^----cannot resolve symbol/variable response
{   JOptionPane.showMessageDialog
          ("Invalid Command");
System.exit (0);
}

Answer 1

1.
JOptionPane.showInputDialog
           ^----not a statement
        ("Input Command");
JOptionPane.showInputDialog("Input Command");
           ^----is a statement2.
if{
else     (response.equals("RUN NOTEPAD"))
        Runtime.getRuntime().exec("notepad.exe");
else
if  (response.equals("null"))
     ^----cannot resolve symbol/variable responseI can't see how that is the only error the compiler gave you.
Try it more like this:
String response = JOption.showInputDialog("Input Command");
if("RUN NOTEPAD".equals(response))
    Runtime.getRuntime().exec("notepad.exe");
else
    JOptionPane.showMessageDialog("Invalid Command");Doing the "RUN".equals(response) ensures we won't get a NullPointException if response is null (as we would if we did response.equals("RUN") style).