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   

JOptionPane makes it easy to pop up a standard dialog box that prompts users for a value or informs them of something. For information about using JOptionPane, see How to Make Dialogs, a section in The Java Tutorial.

While the JOptionPane class may appear complex because of the large number of methods, almost all uses of this class are one-line calls to one of the static showXxxDialog methods shown below:

Method Name	Description
showConfirmDialog	Asks a confirming 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 showInternalXXX flavor, which uses an internal frame to hold the dialog box (see JInternalFrame ). Multiple convenience methods have also been defined -- overloaded versions of the basic methods that use different parameter lists.

All dialogs are modal. Each showXxxDialog method blocks the current thread 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 ComponentOrientation property.

Parameters:
The parameters to these methods follow consistent patterns:

parentComponent

Defines the Component that is to be the parent of this dialog box. It is used in two ways: the Frame that contains it is used as the Frame 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 null, in which case a default Frame 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 String or String constant. However, the type of this parameter is actually Object. Its interpretation depends on its type:

Object[]

An array of objects is interpreted as a series of messages (one per object) arranged in a vertical stack. The interpretation is recursive -- each object in the array is interpreted according to its type.

Component

The Component is displayed in the dialog.

Icon

The Icon is wrapped in a JLabel and displayed in the dialog.

others

The object is converted to a String by calling its toString method. The result is wrapped in a JLabel and displayed.

messageType

Defines the style of the message. The Look and Feel manager may lay out the dialog differently depending on this value, and will often provide a default icon. The possible values are:

• ERROR_MESSAGE
• INFORMATION_MESSAGE
• WARNING_MESSAGE
• QUESTION_MESSAGE
• PLAIN_MESSAGE

optionType

Defines the set of option buttons that appear at the bottom of the dialog box:

• DEFAULT_OPTION
• YES_NO_OPTION
• YES_NO_CANCEL_OPTION
• OK_CANCEL_OPTION

You aren't limited to this set of option buttons. You can provide any buttons you want using the options parameter.

options

A more detailed description of the set of option buttons that will appear at the bottom of the dialog box. The usual value for the options parameter is an array of Strings. But the parameter type is an array of Objects. A button is created for each object depending on its type:

Component

The component is added to the button row directly.

Icon

A JButton is created with this as its label.

other

The Object is converted to a string using its toString method and the result is used to label a JButton.

icon

A decorative icon to be placed in the dialog box. A default value for this is determined by the messageType parameter.

title

The title for the dialog box.

initialValue

The default selection (input value).

When the selection is changed, setValue is invoked, which generates a PropertyChangeEvent.

If a JOptionPane has configured to all input setWantsInput the bound property JOptionPane.INPUT_VALUE_PROPERTY can also be listened to, to determine when the user has input or selected a value.

When one of the showXxxDialog methods returns an integer, the possible values are:

• YES_OPTION
• NO_OPTION
• CANCEL_OPTION
• OK_OPTION
• CLOSED_OPTION

Examples:

Show an error dialog that displays the message, 'alert':

JOptionPane.showMessageDialog(null, "alert", "alert", JOptionPane.ERROR_MESSAGE);

Show an internal information dialog with the message, 'information':

JOptionPane.showInternalMessageDialog(frame, "information",

"information", JOptionPane.INFORMATION_MESSAGE);

Show an information panel with the options yes/no and message 'choose one':

JOptionPane.showConfirmDialog(null,

"choose one", "choose one", JOptionPane.YES_NO_OPTION);

Show an internal information dialog with the options yes/no/cancel and message 'please choose one' and title information:

JOptionPane.showInternalConfirmDialog(frame,

"please choose one", "information",

JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.INFORMATION_MESSAGE);

Show a warning dialog with the options OK, CANCEL, title 'Warning', and message 'Click OK to continue':

Object[] options = { "OK", "CANCEL" };
JOptionPane.showOptionDialog(null, "Click OK to continue", "Warning",

JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,

null, options, options[0]);

Show a dialog asking the user to type in a String:

String inputValue = JOptionPane.showInputDialog("Please input a value");

Show a dialog asking the user to select a String:

Object[] possibleValues = { "First", "Second", "Third" };
Object selectedValue = JOptionPane.showInputDialog(null,

"Choose one", "Input",

JOptionPane.INFORMATION_MESSAGE, null,

possibleValues, possibleValues[0]);

Direct Use:
To create and use an JOptionPane directly, the standard pattern is roughly as follows:

     JOptionPane pane = new JOptionPane(arguments);
     pane.set.Xxxx(...); // Configure
     JDialog dialog = pane.createDialog(parentComponent, title);
     dialog.show();
     Object selectedValue = pane.getValue();
     if(selectedValue == null)
       return CLOSED_OPTION;
     //If there is not an array of option buttons:
     if(options == null) {
       if(selectedValue instanceof Integer)
          return ((Integer)selectedValue).intValue();
       return CLOSED_OPTION;
     }
     //If there is an array of option buttons:
     for(int counter = 0, maxCounter = options.length;
        counter < maxCounter; counter++) {
        if(options[counter].equals(selectedValue))
        return counter;
     }
     return CLOSED_OPTION;
 

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans^TM has been added to the java.beans package. Please see XMLEncoder .

See Also:

JInternalFrame , Serialized Form

Nested Class Summary

protected class

JOptionPane.AccessibleJOptionPane This class implements accessibility support for the JOptionPane class.

Nested classes/interfaces inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes/interfaces inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent , Component.BltBufferStrategy , Component.FlipBufferStrategy

Field Summary

static int	CANCEL_OPTION Return value from class method if CANCEL is chosen.
static int	CLOSED_OPTION Return value from class method if user closes window without selecting anything, more than likely this should be treated as either a CANCEL_OPTION or NO_OPTION.
static int	DEFAULT_OPTION Type used for showConfirmDialog.
static int	ERROR_MESSAGE Used for error messages.
protected Icon	icon Icon used in pane.
static String	ICON_PROPERTY Bound property name for icon.
static int	INFORMATION_MESSAGE Used for information messages.
static String	INITIAL_SELECTION_VALUE_PROPERTY Bound property name for initialSelectionValue.
static String	INITIAL_VALUE_PROPERTY Bound property name for initialValue.
protected Object	initialSelectionValue Initial value to select in selectionValues.
protected Object	initialValue Value that should be initially selected in options.
static String	INPUT_VALUE_PROPERTY Bound property name for inputValue.
protected Object	inputValue Value the user has input.
protected Object	message Message to display.
static String	MESSAGE_PROPERTY Bound property name for message.
static String	MESSAGE_TYPE_PROPERTY Bound property name for type.
protected int	messageType Message type.
static int	NO_OPTION Return value from class method if NO is chosen.
static int	OK_CANCEL_OPTION Type used for showConfirmDialog.
static int	OK_OPTION Return value form class method if OK is chosen.
static String	OPTION_TYPE_PROPERTY Bound property name for optionType.
protected Object []	options Options to display to the user.
static String	OPTIONS_PROPERTY Bound property name for option.
protected int	optionType Option type, one of DEFAULT_OPTION, YES_NO_OPTION, YES_NO_CANCEL_OPTION or OK_CANCEL_OPTION.
static int	PLAIN_MESSAGE No icon is used.
static int	QUESTION_MESSAGE Used for questions.
static String	SELECTION_VALUES_PROPERTY Bound property name for selectionValues.
protected Object []	selectionValues Array of values the user can choose from.
static Object	UNINITIALIZED_VALUE Indicates that the user has not yet selected a value.
protected Object	value Currently selected value, will be a valid option, or UNINITIALIZED_VALUE or null.
static String	VALUE_PROPERTY Bound property name for value.
static String	WANTS_INPUT_PROPERTY Bound property name for wantsInput.
protected boolean	wantsInput If true, a UI widget will be provided to the user to get input.
static int	WARNING_MESSAGE Used for warning messages.
static int	YES_NO_CANCEL_OPTION Type used for showConfirmDialog.
static int	YES_NO_OPTION Type used for showConfirmDialog.
static int	YES_OPTION Return value from class method if YES is chosen.

Fields inherited from class javax.swing.JComponent

accessibleContext , listenerList , TOOL_TIP_TEXT_KEY , ui , UNDEFINED_CONDITION , WHEN_ANCESTOR_OF_FOCUSED_COMPONENT , WHEN_FOCUSED , WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT , CENTER_ALIGNMENT , LEFT_ALIGNMENT , RIGHT_ALIGNMENT , TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT , ALLBITS , ERROR , FRAMEBITS , HEIGHT , PROPERTIES , SOMEBITS , WIDTH

Constructor Summary

JOptionPane ()
Creates a JOptionPane with a test message.

JOptionPane (Object message)
Creates a instance of JOptionPane to display a message using the plain-message message type and the default options delivered by the UI.

JOptionPane (Object message, int messageType)
Creates an instance of JOptionPane to display a message with the specified message type and the default options,

JOptionPane (Object message, int messageType, int optionType)
Creates an instance of JOptionPane to display a message with the specified message type and options.

JOptionPane (Object message, int messageType, int optionType, Icon icon)
Creates an instance of JOptionPane to display a message with the specified message type, options, and icon.

JOptionPane (Object message, int messageType, int optionType, Icon icon, Object [] options)
Creates an instance of JOptionPane to display a message with the specified message type, icon, and options.

JOptionPane (Object message, int messageType, int optionType, Icon icon, Object [] options, Object initialValue)
Creates an instance of JOptionPane to display a message with the specified message type, icon, and options, with the initially-selected option specified.

Method Summary

JDialog	createDialog (Component parentComponent, String title) Creates and returns a new JDialog wrapping this centered on the parentComponent in the parentComponent's frame.
JInternalFrame	createInternalFrame (Component parentComponent, String title) Creates and returns an instance of JInternalFrame.
AccessibleContext	getAccessibleContext () Returns the AccessibleContext associated with this JOptionPane.
static JDesktopPane	getDesktopPaneForComponent (Component parentComponent) Returns the specified component's desktop pane.
static Frame	getFrameForComponent (Component parentComponent) Returns the specified component's Frame.
Icon	getIcon () Returns the icon this pane displays.
Object	getInitialSelectionValue () Returns the input value that is displayed as initially selected to the user.
Object	getInitialValue () Returns the initial value.
Object	getInputValue () Returns the value the user has input, if wantsInput is true.
int	getMaxCharactersPerLineCount () Returns the maximum number of characters to place on a line in a message.
Object	getMessage () Returns the message-object this pane displays.
int	getMessageType () Returns the message type.
Object []	getOptions () Returns the choices the user can make.
int	getOp