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Class datarep.common.Util

java.lang.Object
   |
   +----datarep.common.Util

public class Util
extends Object
datarep.common.Util is a catch-all class with various useful static methods.

Version:
1.2
Author:
Data Representations, Inc.

Constructor Index

 o Util()

Method Index

 o backup(File)
backup: A utility method for making a backup of a file.
 o bubbleSort(String[])
bubbleSort: A utility method for performing a bubble sort on an array of strings.
 o changeDirectory(String)
changeDirectory: changes the default user directory to be used in file operations.
 o changeProperty(String, String)
changeProperty: changes a system property.
 o copyFromClipboard(Component)
copyFromClipboard: returns text from the System clipboard.
 o copyToClipboard(Component, String)
copyToClipboard: copies some text to the system clipboard.
 o drawCenteredString(Graphics, String, int, int)
drawCenteredString: draws a centered string in a particular graphics context.
 o fileCopy(File, File)
fileCopy: Copies a file.
 o fileCopy(InputStream, File)
fileCopy: Copies a file.
 o fileCopy(URL, File)
fileCopy: Copies a file.
 o getApplet(Component)
getApplet: returns the Applet which a component belongs to.
 o getFrame(Component)
getFrame: returns the Frame to which a component belongs.
 o getTopPanel(Component)
getTopPanel: returns the top panel which a component belongs to.
 o getWindow(Component)
getWindow: returns the Window to which a component belongs.
 o readln()
readln(): reads in a line of text from System.in.
 o readln(boolean)
readln(boolean block): reads in a line of text from System.in.
 o stripLF(String)
stripLF: a utility method for removing line feeds from strings.

Constructors

 o Util
 public Util()

Methods

 o getFrame
 public static Frame getFrame(Component comp)
getFrame: returns the Frame to which a component belongs. If a component does not belong to any Frame, returns null.

Parameters:
comp - the component in question
Returns:
returns the Frame which is the "parent" of the component, or null if there is no such frame.
 o getWindow
 public static Window getWindow(Component comp)
getWindow: returns the Window to which a component belongs. If a component does not belong to any Window, returns null.

Parameters:
comp - the component in question
Returns:
returns the Window which is the "parent" of the component, or null if there is no such window.
 o getApplet
 public static Applet getApplet(Component comp)
getApplet: returns the Applet which a component belongs to. If a component does not belong to an Applet, returns null.

Parameters:
comp - the component in question
Returns:
returns the Applet which is the "parent" of the component, or null.
 o getTopPanel
 public static Component getTopPanel(Component comp)
getTopPanel: returns the top panel which a component belongs to. If a component does not belong to a panel at all, returns null. This is useful because it is possible (and sometimes necessary) to nest panels.

Parameters:
comp - the component in question
Returns:
returns the top panel which is a "parent" of the component, or null.
 o drawCenteredString
 public static void drawCenteredString(Graphics g,
                                       String str,
                                       int x,
                                       int y)
drawCenteredString: draws a centered string in a particular graphics context.

 o fileCopy
 public static boolean fileCopy(File source,
                                File destination)
fileCopy: Copies a file. Returns a boolean corresponding to whether or not the copy was sucessful.

Parameters:
source - a File object corresponding to the source file
destination - a File object corresponding to the destination
Returns:
returns true if copy was sucessful; false if not.
 o fileCopy
 public static boolean fileCopy(URL source,
                                File destination)
fileCopy: Copies a file. Returns a boolean corresponding to whether or not the copy was sucessful.

Parameters:
source - a URL corresponding to the location of the source file
destination - a File object corresponding to the destination
Returns:
returns true if copy was sucessful; false if not.
 o fileCopy
 public static boolean fileCopy(InputStream source,
                                File destination)
fileCopy: Copies a file. Returns a boolean corresponding to whether or not the copy was sucessful.

Parameters:
source - an InputStream corresponding to the source file
destination - a File object corresponding to the destination. If a file already exists, it will be overwritten.
Returns:
returns true if copy was sucessful; false if not.
 o changeDirectory
 public static String changeDirectory(String dir)
changeDirectory: changes the default user directory to be used in file operations. Returns a string which is the previous directory. Note that the string is not checked at this stage to see if it is a valid directory.

Parameters:
dir - the name of the new directory
Returns:
returns a string which is the previous default directory.
 o changeProperty
 public static String changeProperty(String key,
                                     String value)
changeProperty: changes a system property. Returns a string which corresponds to the old value of the property.

Parameters:
key - the name of the property to be changed (e.g. "user.dir")
value - the new value for the property.
Returns:
returns a string which corresponds to the old value of the property.
 o readln
 public static String readln()
readln(): reads in a line of text from System.in. Stops reading if it encounters the end of a line, or if there are no incoming characters (i.e. System.in.available() = 0). The end of a line is a line feed or carriage return or an escape. readln returns a string of the text read in (but not including the final line feed/carriage return).

Returns:
returns a string of the text read in.
 o readln
 public static String readln(boolean block)
readln(boolean block): reads in a line of text from System.in. If block is false, the behavior is identical to readln(). If block is true, readln only stops reading if it encounters the end of a line. The end of a line is a line feed or carriage return or an escape. readln returns a string of the text read in (but not including the final line feed/carriage return).

Returns:
returns a string of the text read in.
 o copyToClipboard
 public static void copyToClipboard(Component owner,
                                    String text)
copyToClipboard: copies some text to the system clipboard.

Parameters:
owner - any component (needed to access the system clipboard; which one is not important)
text - the text to be copied to the clipboard
 o copyFromClipboard
 public static String copyFromClipboard(Component owner)
copyFromClipboard: returns text from the System clipboard. If the clipboard doesn't contain text, "" is returned.

Parameters:
owner - any component (needed to access the system clipboard; which one is not important)
Returns:
returns a String corresponding to the contents of the clipboard, or "" if an error occurs.
 o bubbleSort
 public static void bubbleSort(String strings[])
bubbleSort: A utility method for performing a bubble sort on an array of strings. This method uses the java.lang.String.compareTo method to perform a lexicographical comparison. The array will be sorted in ascending order (A-Z,a-z).

The bubble sort is a fairly simple sorting algorithm. There are many places where a complete discussion of various sorting algorithms can be found.

Parameters:
strings - the String array which will be sorted.
See Also:
compareTo
 o backup
 public static void backup(File original)
backup: A utility method for making a backup of a file. If the file being saved exists, then a backup will be made, in a new sub-directory called "Backup". If a backup file already exists in this directory, it will be replaced with the new backup. This method will output a warning to standard output if it is unable to perform a backup or encounters an exception.

Parameters:
original - the File object which is to be backed up.
 o stripLF
 public static String stripLF(String in)
stripLF: a utility method for removing line feeds from strings. This will replace a line feed (\r) with a carriage return (\n), or a \r \n combination with a single \n. A \0 escape character will also be replaced with a \n.

Parameters:
in - String which will have line feeds stripped
Returns:
returns a string with line feeds removed as described above

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