com.lf.commons.info

Class JarInfo

java.lang.Object

com.lf.commons.info.JarInfo

All Implemented Interfaces:

java.util.EventListener, javax.swing.event.ListSelectionListener

public class JarInfo
extends java.lang.Object
implements javax.swing.event.ListSelectionListener

Lightweight main class presented when the module JAR is executed directly.

If the client computer has a graphical output screen then a simple dialog frame is presented. If the client lacks GUI support, the infos are presented over the command line interface. Both variants present the contents of the MANIFEST.MF file. Remember that this class must not use any Java classes either included in the JRE or that are part of this JAR file. For example the VFS classes are not accessible and must therefore not be used from this class. The easiest way to deal with is to simply utilize the standard Java JRE classes. So this class can be integrated into any standalone package.

Since:

1.5

Author:

Axel Schwolow

Constructor Summary

Constructors

Constructor and Description
JarInfo() Constructor method for the manifest display.

Method Summary

Methods

Modifier and Type	Method and Description
static java.awt.Point	centerForWindow(java.awt.Window parent, int width, int height) Calculates the position for a dialog window on the screen.
static java.util.Vector	extractAll(java.lang.String string, java.lang.String regex) Searches strings for certain patterns and returns all results.
boolean	extractZipArchive(java.io.File zipfile, java.io.File targetdir, java.util.ResourceBundle bundle) This extracts a given local ZIP/JAR file directly to a specified directory.
static void	main(java.lang.String[] args) This can be used for the application be executed standalone.
static void	replace(java.lang.StringBuffer buffer, java.lang.String pattern, java.lang.String substitute) Replaces a specific pattern (sub-string) in a String.
static boolean	saveZIPEntry(java.util.zip.ZipFile archive, java.util.zip.ZipEntry entry, java.io.File target) This method stores the content of a ZIP/JAR entry to a local file.
static int	searchIndex(java.lang.String tosearch, java.lang.String pattern) Searches a String for a specific pattern (sub-string).
void	valueChanged(javax.swing.event.ListSelectionEvent e) Called whenever the value of the selection changes.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JarInfo

public JarInfo()

Constructor method for the manifest display.

Since:

1.5

Method Detail

centerForWindow

public static java.awt.Point centerForWindow(java.awt.Window parent,
                             int width,
                             int height)

Calculates the position for a dialog window on the screen.

Can be used to center a dialog for its parent window. If the parent window is null then the point is calculated for the whole desktop automatically.

Parameters:

parent - The parent window to center the dialog, for desktop if null

width - The width of the dialog to be centered

height - The height of the dialog to be centered

Returns:

The position on the screen

Since:

1.5

extractZipArchive

public boolean extractZipArchive(java.io.File zipfile,
                        java.io.File targetdir,
                        java.util.ResourceBundle bundle)

This extracts a given local ZIP/JAR file directly to a specified directory.

The archive is first of all copied to the user's home directory since we cannot extract non-local files (ZipFile has only constructor with File parameter). This method uses the name of the ZIP archive directly. Then the file is extracted.

Parameters:

zipfile - ZIP/JAR archive to extract

targetdir - The local destination directory

bundle - The strings

Returns:

true, if saving worked, false else

Since:

1.6

saveZIPEntry

public static boolean saveZIPEntry(java.util.zip.ZipFile archive,
                   java.util.zip.ZipEntry entry,
                   java.io.File target)

This method stores the content of a ZIP/JAR entry to a local file.

Parameters:

archive - ZIP/JAR archive to copy file from

entry - Source to be copied

target - The local file to store the content

Returns:

true, if saving worked

Since:

1.5

extractAll

public static java.util.Vector extractAll(java.lang.String string,
                          java.lang.String regex)

Searches strings for certain patterns and returns all results.

Search patterns are defined in shape of regular expressions used by the method "String.matches" (since SDK 1.4.1). See the Java API documentation for details.

Parameters:

string - The string to be searched

regex - The regular expression pattern to be searched for

Returns:

List of substrings, may be empty

replace

public static void replace(java.lang.StringBuffer buffer,
           java.lang.String pattern,
           java.lang.String substitute)

Replaces a specific pattern (sub-string) in a String.

The return value counts the replacements. If the substitute parameter is null the found pattern substrings are simply removed from string. Since this method uses the fast searching routines by Knuth-Morris-Pratt the searched String objects may be large.

Parameters:

buffer - The StringBuffer object for search & replace

pattern - This sub-string is the search target

substitute - The found patterns are substituted by this

Since:

1.5

searchIndex

public static int searchIndex(java.lang.String tosearch,
              java.lang.String pattern)

Searches a String for a specific pattern (sub-string).

It does a pattern matching therefore. Since the brute-force algorithm is much too slow for our purpose we use the well-known Knuth-Morris-Pratt algorithm here for very fast searching. This method is directly derived from the PXINDEX project by the same author ;-) This method variation does not only give the response if the pattern was found or not, but returns the next index which has not been processed after the substring was found. So calling methods may replace the sub-string and start searching again. If the pattern was not found within the search string the method returns -1.

Parameters:

tosearch - The string to be searched

pattern - This sub-string is the search target

Returns:

Next unprocessed index if found, else -1

Since:

1.5

main

public static void main(java.lang.String[] args)

This can be used for the application be executed standalone.

Parameters:

args - Array of strings with console arguments

Since:

1.5

valueChanged

public void valueChanged(javax.swing.event.ListSelectionEvent e)

Called whenever the value of the selection changes.

Specified by:

valueChanged in interface javax.swing.event.ListSelectionListener

Parameters:

e - Event object reference

Since:

1.6