JoptionPane In Java

JoptionPane Class:-

Data Input

● There are 2 ways to take input in Java 

– JOptionPane class 

– Scanner class

 

● JOptionPane makes it easy to pop up a standard dialog box that prompts users for a value or informs them of something 

1)showConfirmDialog

 

● This method is a quick and easy way to get user input by asking a confirming question, like yes/no/cancel . 

● The showConfirmDialog() can be called using the following combinations of parameters:

Component, Object 

Component, Object, String, int 

Component, Object, String, int, int 

Component, Object, String, int, int, Icon

● Component – The first parameter is a Component which determines the Frame in which the dialog is displayed; if null, or if the parentComponent has no Frame, a default Frame is used. 

● Object – The second parameter can be any Object. (In some older versions of Java you might get a compiler error when using primitive types directly) 

● String – The third parameter is a String placed as the title of the confirmDialog window. 

● int – The int that follows the String is the OptionType. The different OptionTypes for JOptionPane, are: 

–   DEFAULT_OPTION 

–   YES_NO_OPTION 

–   YES_NO_CANCEL_OPTION 

–    OK_CANCEL_OPTION

● int – The next int is the MessageType. The different MessageTypes for JOptionPane, are: 

–    ERROR_MESSAGE 

–    INFORMATION_MESSAGE 

–    WARNING_MESSAGE 

–    QUESTION_MESSAGE 

–    PLAIN_MESSAGE 

● Icon – The last parameter is an Icon that is displayed inside the dialog and overrides the default MessageType icon.

1. Component & Object 

● Simplest way to get user input. 

● The showConfirmDialog() will bring up a dialog with the options Yes, No and Cancel and the title “Select an Option”:

Syntex:-

 int input = JOptionPane.showConfirmDialog(null, "Do you like Java?");

        // 0=yes, 1=no, 2=cancel       

         System.out.println(input);

2. Component, Object, String & int

● Adding some more information to the confirmation dialog. 

● In this example we get to choose the title of the dialog as well as the optionType. 

● The DEFAULT_OPTION has only an “OK” button. 

● This form of the confirmation dialog is equivalent to a simple showMessageDialog() while giving us the ability to get the user input.

3. Component, Object, String, int & int 

● Give your confirmation dialog with error icon: 

● Example

 int input = JOptionPane.showConfirmDialog(null, "Do you want to proceed?", "Select an Option...", 

JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.ERROR_MESSAGE);

4. Component, Object, String, int, int & icon 

● Make your confirmation dialog “prettier” 

● Example with Icon retrieved from a directory:

2) showInputDialog

 

● With this method we can prompt the user for input while customizing our dialog window. 

● The showConfirmDialog returns either String or Object and can be called using the following combinations of parameters: 

1. Object (returns String) – Shows a question-message dialog requesting input from the user. 

2. Object, Object (returns String) – Shows a question-message dialog requesting input from the user with the input value initialized.

3. Component, Object (returns String) – Shows a question-message dialog requesting input from the user. Returns the input as String. The Component determines the Frame in which the dialog is displayed; if null, or if the parentComponent has no Frame, a default Frame is used. 

4. Component, Object, Object (returns String) – Same as above. The only difference is that the input field has an initial value set through the last Object parameter. 

5. Component, Object, String, int (returns String) – Shows a dialog requesting input from the user. The dialog has a title set through the String parameter and a MessageType set through the int parameter. The different MessageTypes for JOptionPane, are: 

ERROR_MESSAGE, 

INFORMATION_MESSAGE,

WARNING_MESSAGE,

QUESTION_MESSAGE, 

PLAIN_MESSAGE

3) showMessageDialog

● It is used to create a message dialog with given title and messageType. 

Syntex

void showMessageDialog(Component parentComponent, Object message, String title, int messageType)

4) showOptionDialog

 

● The showOptionDialog method of JOptionPane is the Grand Unification of showConfirmDialog, showInputDialog and showMessageDialog. 

● The showOptionDialog returns an integer which represents the position of the user’s choice in the Object[].

JOptionPane.showOptionDialog(null        // position the dialog, the default position is center.

, “Message?”                                              // display Message , 

“Title”                                                       // Title in titlebar ,

JOptionPane.NO_OPTION                     // Option type ,

JOptionPane.PLAIN_MESSAGE          // messageType , 

null                                                         // Icon (none) , 

buttons                                                    // Button text as above. 

,“default”);                                              // Default button’s label

Using JoptionPane Class for GUI I/O

import javax.swing.JOptionPane;

 JOptionPane.showInputDialog("Enter Value 1:") 

● JOptionPane.showMessageDialog (null, "Messagehere", "Title here", JoptionPane.PLAIN_MESSAGE); 

● JOptionPane.PLAIN_MESSAGE // this is a plain message 

● JOptionPane.INFORMATION_MESSAGE // this is a info message 

● JOptionPane.ERROR_MESSAGE // this is a error message 

● JOptionPane.WARNING_MESSAGE // this is a warning message 

                             ALso You Can Check Out OUr JAva Artical JUst Click --> Hear

NeXt Artical Related Scanner Class

 

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