1. JFrame Class
The JFrame class is slightly incompatible with Frame. Like all other JFC/Swing top-level
containers, a JFrame contains a JRootPane as its only child. The content pane provided by the
root pane should, as a rule, contain all the non-menu components displayed by the JFrame.
This is different from the AWT Frame case. As a conveniance add and its variants, remove
and setLayout have been overridden to forward to the contentPane as necessary. This means
you can write:
frame.add(child);
The JFrame class have a lot of methods.
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.
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

2. 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.

3. 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
JOptionPane
JOptionPane.showConfirmDialog() :

4. JOptionPane.showMessageDialog() :
JOptionPane.showInputDialog() ;

5. JOptionPane.showOptionDialog() :
JCheckBox

6. JPanel Class
The JPanel class provides general-purpose containers for lightweight components. By
default, panels do not add colors to anything except their own background; however, you
can easily add borders to them and otherwise customize their painting.
Setting the Layout Manager
Like other containers, a panel uses a layout manager to position and size its components.
By default, a panel's layout manager is an instance of FlowLayout, which places the panel's
contents in a row. You can easily make a panel use any other layout manager by invoking
the setLayout method or by specifying a layout manager when creating the panel. The latter
approach is preferable for performance reasons, since it avoids the unnecessary creation
of a FlowLayout object.
Here is an example of how to set the layout manager when creating the panel.
JPanel p = new JPanel(new BorderLayout()); //PREFERRED!
This approach does not work with BoxLayout, since the BoxLayout constructor requires a pre-
existing container. Here is an example that uses BoxLayout.
JPanel p = new JPanel();
p.setLayout(new BoxLayout(p, BoxLayout.PAGE_AXIS));

7. Adding Components
When you add components to a panel, you use the add method. Exactly which arguments
you specify to the add method depend on which layout manager the panel uses. When the
layout manager is FlowLayout, BoxLayout, GridLayout, or SpringLayout, you will typically use the
one-argument add method, like this:
aFlowPanel.add(aComponent);
aFlowPanel.add(anotherComponent);
When the layout manager is BorderLayout, you need to provide an argument specifying the
added component's position within the panel. For example:
aBorderPanel.add(aComponent, BorderLayout.CENTER);
aBorderPanel.add(anotherComponent, BorderLayout.PAGE_END);
With GridBagLayout you can use either add method, but you must somehow specify grid bag
constraints for each component.