javax.swing
Class JProgressBar

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--javax.swing.JComponent
                    |
                    +--javax.swing.JProgressBar

All Implemented Interfaces:

Accessible, ImageObserver, MenuContainer, Serializable, SwingConstants

public class JProgressBar

extends JComponent

implements SwingConstants, Accessible

A component that, by default, displays an integer value within a bounded interval. A progress bar typically communicates the progress of some work by displaying its percentage of completion and possibly a textual display of this percentage.

To indicate that a task of unknown length is executing, you can put a progress bar into indeterminate mode. While the bar is in indeterminate mode, it animates constantly to show that work is occurring. As soon as you can determine the task's length and amount of progress, you should update the progress bar's value and switch it back to determinate mode.

Here is an example of creating a progress bar, where task is an object that returns information about the progress of some work:

progressBar = new JProgressBar(0, task.getLengthOfTask());
progressBar.setValue(0);
progressBar.setStringPainted(true);

Here is an example of updating the value of the progress bar:

progressBar.setValue(task.getCurrent());

Here is an example of putting a progress bar into indeterminate mode, and then switching back to determinate mode once the length of the task is known:

progressBar = new JProgressBar();
./when the task of (initially) unknown length begins:
progressBar.setIndeterminate(true);
./do some work; get length of task...
progressBar.setMaximum(newLength);
progressBar.setValue(newValue);
progressBar.setIndeterminate(false);

For complete examples and further documentation see How to Monitor Progress, a section in The Java Tutorial.

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:

BasicProgressBarUI

Nested Class Summary
protected  class	JProgressBar.AccessibleJProgressBar     This class implements accessibility support for the JProgressBar class.

 

Nested classes inherited from class javax.swing.JComponent

 

Nested classes inherited from class java.awt.Container

 

Nested classes inherited from class java.awt.Component

Component.BltBufferStrategy, Component.FlipBufferStrategy

 

Field Summary
protected  ChangeEvent	changeEvent     Only one ChangeEvent is needed per instance since the event's only interesting property is the immutable source, which is the progress bar.
protected  ChangeListener	changeListener     Listens for change events sent by the progress bar's model, redispatching them to change-event listeners registered upon this progress bar.
protected  BoundedRangeModel	model     The object that holds the data for the progress bar.
protected  int	orientation     Whether the progress bar is horizontal or vertical.
protected  boolean	paintBorder     Whether to display a border around the progress bar.
protected  boolean	paintString     Whether to textually display a string on the progress bar.
protected  String	progressString     An optional string that can be displayed on the progress bar.

 

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 javax.swing.SwingConstants

BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH,