FileDialog (Java SE 14 & JDK 14)
Description: declaration: module: java.desktop, package: java.awt, class: FileDialog
Keywords: java.awt.FileDialog class

Module java.desktop
Package java.awt

# Class FileDialog

java.lang.Object
java.awt.Component
java.awt.Container
java.awt.Window
java.awt.Dialog
java.awt.FileDialog

All Implemented Interfaces:
  `ImageObserver`, `MenuContainer`, `Serializable`, `Accessible`

    public class FileDialog
    extends Dialog

The `FileDialog` class displays a dialog window from which the user can select a file.

Since it is a modal dialog, when the application calls its `show` method to display the dialog, it blocks the rest of the application until the user has chosen a file.

Since:
  1.0
See Also:
  `Window.show()`, Serialized Form

- ## Nested Class Summary

  ## Nested classes/interfaces declared in class java.awt.Dialog

  `Dialog.AccessibleAWTDialog, Dialog.ModalExclusionType, Dialog.ModalityType`

  ## Nested classes/interfaces declared in class java.awt.Window

  `Window.AccessibleAWTWindow, Window.Type`

  ## Nested classes/interfaces declared in class java.awt.Container

  `Container.AccessibleAWTContainer`

  ## Nested classes/interfaces declared in class java.awt.Component

  `Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy`

- ## Field Summary

  Fields
  Modifier and Type | Field | Description
  --- | --- | ---
  `static int` | `LOAD` | This constant value indicates that the purpose of the file dialog window is to locate a file from which to read.
  `static int` | `SAVE` | This constant value indicates that the purpose of the file dialog window is to locate a file to which to write.

  ### Fields declared in class java.awt.Dialog

  `DEFAULT_MODALITY_TYPE`

  ### Fields declared in class java.awt.Component

  `accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT`

  ### Fields declared in interface java.awt.image.ImageObserver

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

- ## Constructor Summary

  Constructors
  Constructor | Description
  --- | ---
  `FileDialog​(Dialog parent)` | Creates a file dialog for loading a file.
  `FileDialog​(Dialog parent, String title)` | Creates a file dialog window with the specified title for loading a file.
  `FileDialog​(Dialog parent, String title, int mode)` | Creates a file dialog window with the specified title for loading or saving a file.
  `FileDialog​(Frame parent)` | Creates a file dialog for loading a file.
  `FileDialog​(Frame parent, String title)` | Creates a file dialog window with the specified title for loading a file.
  `FileDialog​(Frame parent, String title, int mode)` | Creates a file dialog window with the specified title for loading or saving a file.

- ## Method Summary

  Modifier and Type | Method | Description
  --- | --- | ---
  `void` | `addNotify()` | Creates the file dialog's peer.
  `String` | `getDirectory()` | Gets the directory of this file dialog.
  `String` | `getFile()` | Gets the selected file of this file dialog.
  `FilenameFilter` | `getFilenameFilter()` | Determines this file dialog's filename filter.
  `File[]` | `getFiles()` | Returns files that the user selects.
  `int` | `getMode()` | Indicates whether this file dialog box is for loading from a file or for saving to a file.
  `boolean` | `isMultipleMode()` | Returns whether the file dialog allows the multiple file selection.
  `protected String` | `paramString()` | Returns a string representing the state of this `FileDialog` window.
  `void` | `setDirectory​(String dir)` | Sets the directory of this file dialog window to be the specified directory.
  `void` | `setFile​(String file)` | Sets the selected file for this file dialog window to be the specified file.
  `void` | `setFilenameFilter​(FilenameFilter filter)` | Sets the filename filter for this file dialog window to the specified filter.
  `void` | `setMode​(int mode)` | Sets the mode of the file dialog.
  `void` | `setMultipleMode​(boolean enable)` | Enables or disables multiple file selection for the file dialog.
  `void` | `setTitle​(String title)` | Sets the title of the Dialog.

  ### Methods declared in class java.awt.Dialog

  `getAccessibleContext, getModalityType, getTitle, hide, isModal, isResizable, isUndecorated, setModal, setModalityType, setResizable, setUndecorated, setVisible, show, toBack`

  ### Methods declared in class java.awt.Window

  `addPropertyChangeListener, addPropertyChangeListener, addWindowFocusListener, addWindowListener, addWindowStateListener, applyResourceBundle, applyResourceBundle, createBufferStrategy, createBufferStrategy, dispose, getBackground, getBufferStrategy, getFocusableWindowState, getFocusCycleRootAncestor, getFocusOwner, getFocusTraversalKeys, getIconImages, getInputContext, getListeners, getLocale, getModalExclusionType, getMostRecentFocusOwner, getOpacity, getOwnedWindows, getOwner, getOwnerlessWindows, getShape, getToolkit, getType, getWarningString, getWindowFocusListeners, getWindowListeners, getWindows, getWindowStateListeners, isActive, isAlwaysOnTop, isAlwaysOnTopSupported, isAutoRequestFocus, isFocusableWindow, isFocusCycleRoot, isFocused, isLocationByPlatform, isOpaque, isShowing, isValidateRoot, pack, paint, postEvent, processEvent, processWindowEvent, processWindowFocusEvent, processWindowStateEvent, removeWindowFocusListener, removeWindowListener, removeWindowStateListener, reshape, setAlwaysOnTop, setAutoRequestFocus, setBackground, setBounds, setBounds, setCursor, setFocusableWindowState, setFocusCycleRoot, setIconImage, setIconImages, setLocation, setLocation, setLocationByPlatform, setLocationRelativeTo, setMinimumSize, setModalExclusionType, setOpacity, setShape, setSize, setSize, setType, toFront`

  ### Methods declared in class java.awt.Container

  `add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalPolicy, getInsets, getLayout, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, print, printComponents, processContainerEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, setLayout, transferFocusDownCycle, update, validate, validateTree`

  ### Methods declared in class java.awt.Component

  `action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, resize, resize, revalidate, setComponentOrientation, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setMaximumSize, setMixingCutoutShape, setName, setPreferredSize, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle`

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### LOAD

    public static final int LOAD
    This constant value indicates that the purpose of the file dialog window is to locate a file from which to read.
    See Also:
      Constant Field Values

  - ### SAVE

    public static final int SAVE
    This constant value indicates that the purpose of the file dialog window is to locate a file to which to write.
    See Also:
      Constant Field Values

- ## Constructor Details

  - ### FileDialog

    public FileDialog​(Frame parent)
    Creates a file dialog for loading a file. The title of the file dialog is initially empty. This is a convenience method for `FileDialog(parent, "", LOAD)`.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
    Since:
      1.1

  - ### FileDialog

    public FileDialog​(Frame parent, String title)
    Creates a file dialog window with the specified title for loading a file. The files shown are those in the current directory. This is a convenience method for `FileDialog(parent, title, LOAD)`.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
      `title` - the title of the dialog

  - ### FileDialog

    public FileDialog​(Frame parent, String title, int mode)
    Creates a file dialog window with the specified title for loading or saving a file.

    If the value of `mode` is `LOAD`, then the file dialog is finding a file to read, and the files shown are those in the current directory. If the value of `mode` is `SAVE`, the file dialog is finding a place to write a file.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
      `title` - the title of the dialog
      `mode` - the mode of the dialog; either `FileDialog.LOAD` or `FileDialog.SAVE`
    Throws:
      `IllegalArgumentException` - if an illegal file dialog mode is supplied
    See Also:
      `LOAD`, `SAVE`

  - ### FileDialog

    public FileDialog​(Dialog parent)
    Creates a file dialog for loading a file. The title of the file dialog is initially empty. This is a convenience method for `FileDialog(parent, "", LOAD)`.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
    Throws:
      `IllegalArgumentException` - if the `parent`'s `GraphicsConfiguration` is not from a screen device;
      `IllegalArgumentException` - if `parent` is `null`; this exception is always thrown when `GraphicsEnvironment.isHeadless` returns `true`
    Since:
      1.5
    See Also:
      `GraphicsEnvironment.isHeadless()`

  - ### FileDialog

    public FileDialog​(Dialog parent, String title)
    Creates a file dialog window with the specified title for loading a file. The files shown are those in the current directory. This is a convenience method for `FileDialog(parent, title, LOAD)`.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
      `title` - the title of the dialog; a `null` value will be accepted without causing a `NullPointerException` to be thrown
    Throws:
      `IllegalArgumentException` - if the `parent`'s `GraphicsConfiguration` is not from a screen device;
      `IllegalArgumentException` - if `parent` is `null`; this exception is always thrown when `GraphicsEnvironment.isHeadless` returns `true`
    Since:
      1.5
    See Also:
      `GraphicsEnvironment.isHeadless()`

  - ### FileDialog

    public FileDialog​(Dialog parent, String title, int mode)
    Creates a file dialog window with the specified title for loading or saving a file.

    If the value of `mode` is `LOAD`, then the file dialog is finding a file to read, and the files shown are those in the current directory. If the value of `mode` is `SAVE`, the file dialog is finding a place to write a file.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Parameters:
      `parent` - the owner of the dialog
      `title` - the title of the dialog; a `null` value will be accepted without causing a `NullPointerException` to be thrown
      `mode` - the mode of the dialog; either `FileDialog.LOAD` or `FileDialog.SAVE`
    Throws:
      `IllegalArgumentException` - if an illegal file dialog mode is supplied;
      `IllegalArgumentException` - if the `parent`'s `GraphicsConfiguration` is not from a screen device;
      `IllegalArgumentException` - if `parent` is `null`; this exception is always thrown when `GraphicsEnvironment.isHeadless` returns `true`
    Since:
      1.5
    See Also:
      `GraphicsEnvironment.isHeadless()`, `LOAD`, `SAVE`

- ## Method Details

  - ### setTitle

    public void setTitle​(String title)
    Sets the title of the Dialog.

    Note: Some platforms may not support showing the user-specified title in a file dialog. In this situation, either no title will be displayed in the file dialog's title bar or, on some systems, the file dialog's title bar will not be displayed.

    Overrides:
      `setTitle` in class `Dialog`
    Parameters:
      `title` - the title displayed in the dialog's border; a null value results in an empty title
    See Also:
      `Dialog.getTitle()`

  - ### addNotify

    public void addNotify()
    Creates the file dialog's peer. The peer allows us to change the look of the file dialog without changing its functionality.
    Overrides:
      `addNotify` in class `Dialog`
    See Also:
      `Component.isDisplayable()`, `Container.removeNotify()`

  - ### getMode

    public int getMode()
    Indicates whether this file dialog box is for loading from a file or for saving to a file.
    Returns:
      the mode of this file dialog window, either `FileDialog.LOAD` or `FileDialog.SAVE`
    See Also:
      `LOAD`, `SAVE`, `setMode(int)`

  - ### setMode

    public void setMode​(int mode)
    Sets the mode of the file dialog. If `mode` is not a legal value, an exception will be thrown and `mode` will not be set.
    Parameters:
      `mode` - the mode for this file dialog, either `FileDialog.LOAD` or `FileDialog.SAVE`
    Throws:
      `IllegalArgumentException` - if an illegal file dialog mode is supplied
    Since:
      1.1
    See Also:
      `LOAD`, `SAVE`, `getMode()`

  - ### getDirectory

    public String getDirectory()
    Gets the directory of this file dialog.
    Returns:
      the (potentially `null` or invalid) directory of this `FileDialog`
    See Also:
      `setDirectory(java.lang.String)`

  - ### setDirectory

    public void setDirectory​(String dir)
    Sets the directory of this file dialog window to be the specified directory. Specifying a `null` or an invalid directory implies an implementation-defined default. This default will not be realized, however, until the user has selected a file. Until this point, `getDirectory()` will return the value passed into this method.

    Specifying "" as the directory is exactly equivalent to specifying `null` as the directory.

    Parameters:
      `dir` - the specified directory
    See Also:
      `getDirectory()`

  - ### getFile

    public String getFile()
    Gets the selected file of this file dialog. If the user selected `CANCEL`, the returned file is `null`.
    Returns:
      the currently selected file of this file dialog window, or `null` if none is selected
    See Also:
      `setFile(java.lang.String)`

  - ### getFiles

    public File[] getFiles()
    Returns files that the user selects.

    If the user cancels the file dialog, then the method returns an empty array.

    Returns:
      files that the user selects or an empty array if the user cancels the file dialog.
    Since:
      1.7
    See Also:
      `setFile(String)`, `getFile()`

  - ### setFile

    public void setFile​(String file)
    Sets the selected file for this file dialog window to be the specified file. This file becomes the default file if it is set before the file dialog window is first shown.

    When the dialog is shown, the specified file is selected. The kind of selection depends on the file existence, the dialog type, and the native platform. E.g., the file could be highlighted in the file list, or a file name editbox could be populated with the file name.

    This method accepts either a full file path, or a file name with an extension if used together with the `setDirectory` method.

    Specifying "" as the file is exactly equivalent to specifying `null` as the file.

    Parameters:
      `file` - the file being set
    See Also:
      `getFile()`, `getFiles()`

  - ### setMultipleMode

    public void setMultipleMode​(boolean enable)
    Enables or disables multiple file selection for the file dialog.
    Parameters:
      `enable` - if `true`, multiple file selection is enabled; `false` - disabled.
    Since:
      1.7
    See Also:
      `isMultipleMode()`

  - ### isMultipleMode

    public boolean isMultipleMode()
    Returns whether the file dialog allows the multiple file selection.
    Returns:
      `true` if the file dialog allows the multiple file selection; `false` otherwise.
    Since:
      1.7
    See Also:
      `setMultipleMode(boolean)`

  - ### getFilenameFilter

    public FilenameFilter getFilenameFilter()
    Determines this file dialog's filename filter. A filename filter allows the user to specify which files appear in the file dialog window. Filename filters do not function in Sun's reference implementation for Microsoft Windows.
    Returns:
      this file dialog's filename filter
    See Also:
      `FilenameFilter`, `setFilenameFilter(java.io.FilenameFilter)`

  - ### setFilenameFilter

    public void setFilenameFilter​(FilenameFilter filter)
    Sets the filename filter for this file dialog window to the specified filter. Filename filters do not function in Sun's reference implementation for Microsoft Windows.
    Parameters:
      `filter` - the specified filter
    See Also:
      `FilenameFilter`, `getFilenameFilter()`

  - ### paramString

    protected String paramString()
    Returns a string representing the state of this `FileDialog` window. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be `null`.
    Overrides:
      `paramString` in class `Dialog`
    Returns:
      the parameter string of this file dialog window