Home > Joptionpane Showmessagedialog > Joptionpane Showmessagedialog Null Error

Joptionpane Showmessagedialog Null Error

Method javax.swing Class JOptionPane java.lang.Object java.awt.Component java.awt.Container javax.swing.JComponent javax.swing.JOptionPane All Implemented Interfaces: ImageObserver, MenuContainer, Serializable, Accessible public class JOptionPane extends JComponent implements Accessible 7 makes it easy to pop up a standard dialog box that import joptionpane prompts users for a value or informs them of something. For information about

Joptionpane Showoptiondialog

using 6, see How to Make Dialogs, a section in The Java Tutorial. While the 5 class may appear joptionpane syntax complex because of the large number of methods, almost all uses of this class are one-line calls to one of the static 4 methods shown below: Method Name Description showConfirmDialog Asks a confirming

Joptionpane.showconfirmdialog Example

question, like yes/no/cancel. showInputDialog Prompt for some input. showMessageDialog Tell the user about something that has happened. showOptionDialog The Grand Unification of the above three. Each of these methods also comes in a 3 flavor, which uses an internal frame to hold the dialog box (see 2). Multiple convenience methods have also been defined -- overloaded versions of the basic methods that use different parameter lists. joptionpane output All dialogs are modal. Each 1 method blocks the caller until the user's interaction is complete. icon message input value option buttons The basic appearance of one of these dialog boxes is generally similar to the picture at the right, although the various look-and-feels are ultimately responsible for the final result. In particular, the look-and-feels will adjust the layout to accommodate the option pane's 0 property. Parameters: The parameters to these methods follow consistent patterns: parentComponent Defines the 9 that is to be the parent of this dialog box. It is used in two ways: the 8 that contains it is used as the 7 parent for the dialog box, and its screen coordinates are used in the placement of the dialog box. In general, the dialog box is placed just below the component. This parameter may be 6, in which case a default 5 is used as the parent, and the dialog will be centered on the screen (depending on the L&F). message A descriptive message to be placed in the dialog box. In the most common usage, message is just a 4 or 3 constant. However, the type of this parameter is actual

here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings

Joptionpane Yes No

and policies of this site About Us Learn more about Stack Overflow

Joptionpane Error Message

the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation joptionpane multiple input Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it https://docs.oracle.com/javase/7/docs/api/javax/swing/JOptionPane.html only takes a minute: Sign up JOptionPane.showMessageDialog() shows but without any message? up vote 3 down vote favorite In the following code, I call JOptionPane.showMessageDialog, inside a try/catch block. But when the error is caught, my JOptionPane is visible but without any message !!! Does someone knows why and how I can correct the problem ? Regards MyBoardJPannel.java package experimentations.gui; http://stackoverflow.com/questions/7312102/joptionpane-showmessagedialog-shows-but-without-any-message import java.awt.Graphics; import java.awt.Image; import java.io.InputStream; import javax.imageio.ImageIO; import javax.swing.JOptionPane; import javax.swing.JPanel; public class MyBoardPannel extends JPanel { @Override public void paint(Graphics grahics) { if (imageToShow == null) imageToShow = loadImage("sampleImage"); } /** * In fact, there are not any image in project => will go to catch clause. * @param imageName */ private void loadImage(String imageName) { InputStream imageStream = getClass().getResourceAsStream("/"+imageName+".png"); try { imageToShow = ImageIO.read(imageStream); } catch (Exception e) { String errorMessage = "Failed to load image "+imageName; System.err.println(errorMessage); JOptionPane.showMessageDialog(this, errorMessage, "Image loading error", JOptionPane.ERROR_MESSAGE); imageToShow = null; System.exit(1); } } private Image imageToShow; } JOptionPaneErrorShowing.java package experimentations.gui; import javax.swing.JFrame; public class JOptionPaneErrorShowing extends JFrame { public JOptionPaneErrorShowing(){ setTitle("JOptionPane experimentation"); setSize(300, 300); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLocationRelativeTo(null); add(new MyBoardPannel()); } /** * @param args */ public static void main(String[] args) { new JOptionPaneErrorShowing().setVisible(true); } } java swing joptionpane share|improve this question edited Sep 28 '11 at 12:43 Bill the Lizard 223k139448737 asked Sep 5 '11 at 19:37 loloof64 1,34841747 @mKorbel: Please stop adding the sscce tag to posts. It's a meta tag, so it isn't necessary. &ndas

here for a quick overview of the site Help Center Detailed answers to any questions you might http://stackoverflow.com/questions/27852444/java-joptionpane-showinputdialog-errors have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting https://gist.github.com/3082278 ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 joptionpane showmessagedialog million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Java - JOptionPane.showInputDialog errors up vote 0 down vote favorite Hello all I am experiencing issues with my JOptionPane.showInputDialog input field. The issue i am experiencing that is when the cancel button is selected or the OK button joptionpane showmessagedialog null is selected with empty or with categorical i am greeted with an error. Any suggestions. My first attempt at fixing this i changed the c int into an interger therefore i could use an if statement along with null such as Integer cInterger = new Integer(c); if (cInterger.equals(null)){ return;} Along with cInterger == null cInterger !=null But to no avail int a = 0; // int b = 0; // int c = 0; // if (selected) { if (command.equals("amount")) { Scanner readFile = null; try { readFile = new Scanner(new FileReader("BANK.txt")); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } String account = ""; account = readFile.nextLine(); String amount = JOptionPane.showInputDialog(frame,"Enter an amount"); //assign user input to string amount a= Integer.parseInt(account); //conversion of scanned string to int for easy subtraction b= Integer.parseInt(amount); c = a-b; try { if( c == 0){ JOptionPane.showMessageDialog(null,"Granted.","Granted",JOptionPane.WARNING_MESSAGE);} else if (c > 0){ JOptionPane.showMessageDialog(null,"Granted.","Granted",JOptionPane.INFORMATION_MESSAGE); } else{ JOptionPane.showMessageDialog(null,"Denied.","Denied",JOptionPane.ERROR_MESSAGE);} Resulting errors Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatExcep

a GitHub account Sign in Create a gist now Instantly share code, notes, and snippets. Star 0 Fork 0 jake7864/JOptionPaneExample.java forked from anonymous/JOptionPane Example Created Jul 10, 2012 Embed What would you like to do? Embed Embed this gist in your website. Embed Share Copy sharable URL for this gist. Share Clone via HTTPS Clone with Git or checkout with SVN using the repository's web address. HTTPS Learn more about clone URLs Download ZIP Code Revisions 3 na Example of how to use the JOptionPane to make GUIs. Raw JOptionPaneExample.java import javax.swing.JOptionPane; /* ///-_-_- JOPTIONPANE TUTORIAL -_-_-\\\ Hello this is my very first programming tutorial, what is up, this is a tutorial on how to use JOptionPane! up to now you have been using System.out.print() to output messages & you've been using java.util.Scanner to receive input but now I'll tell you how to use JOptionPane's showMessageDialog() & showInputDialog() methods. JOptionPane programs are little pop up windows that either have a dialog box that has a message and asks for input that is the showInputDialog() the other is showMessageDialog, it is just a little message with a Icon if you want, both pop up window types can have a title & both need to have null for the container usually like probably too early for you for me to talk about that. JOptionPane Programs are a lot more easy to use and to work with than the console type programs you have made so far, you will have to import javax.swing.JOptionPane; to use JOptionPane and it's methods. ///-_-_- JOPTIONPANE TUTORIAL -_-_-\\\ */ public class JOpExample { public static void main(String args[]) { //OK first up is the showInputDialog() it gives prompt and returns user input String input = JOptionPane.showInputDialog(null, "what up", "text box prompt");//Equivalent to java.utilScanner but shows a message, & a title String titleLess = JOptionPane.showInputDialog(null, "no prompt!");//you don't need the prompt but you need the null at the start //showInputDialog and showInputDialog both require the null at the beginning if(input == null)System.exit(0);//if the input ends up being null that means you pressed cancel so adding System.exit(0); will close the program //what ever string that is receiving input needs this afterward so that the cancel button will always work right //and only closing the

 
No related pages.