File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
http://aspose.com/file-tools
The moose likes Beginning Java and the fly likes Very basic question about J.OptionPane.showMessageDialog method Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "Very basic question about J.OptionPane.showMessageDialog method" Watch "Very basic question about J.OptionPane.showMessageDialog method" New topic
Author

Very basic question about J.OptionPane.showMessageDialog method

Karen Haq
Greenhorn

Joined: Mar 17, 2010
Posts: 22
Hi,
I'm trying to understand how to read (i.e., how to translate from geek speak to English) the overwhelming and detailed Java API as I'm learning how to code. Regarding this method I copied from the API:

static String showInputDialog(Object message)
Shows a question-message dialog requesting input from the user.


In "English", this method is a class static method that returns a String type and the method's argument is the class's field message? So how does "Object" come into play here? I understand Object is the root class (of all classes) but I don't understand its relationship to "message" because isn't message a field for J.OptionPane class?
Rob Spoor
Sheriff

Joined: Oct 27, 2005
Posts: 19696
    
  20

The message is of type object because it doesn't have to be a String. You can pass a String[] which will be shown as all Strings below each other, and even complete Components like JTextField, JButton, JPanel, etc.

Although the actual supported Object types are not clearly documented, a little investigation showed that the following are allowed:
- Component: the component will be added
- Icon: a text-less label with the icon will be added
- Object[]: all elements of the array are added using the same code, so the Object[] can contain Component, Icon, Object[], etc
- anything else will be converted into a String which is added as a label


SCJP 1.4 - SCJP 6 - SCWCD 5 - OCEEJBD 6
How To Ask Questions How To Answer Questions
Karen Haq
Greenhorn

Joined: Mar 17, 2010
Posts: 22
Okay, I think I got.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Very basic question about J.OptionPane.showMessageDialog method