Module java.desktop
Package java.awt

Class 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:
  • 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:
    • 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:
  • 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:
    • 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:
    • 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:
    • 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:
  • 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:
    • 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:
    • 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:
    • 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:
    • getDirectory

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

      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:
    • 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

      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:
    • 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:
    • 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:
    • 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