chargerlib

Class JarResources

Object

chargerlib.JarResources

public final class JarResources
extends Object

JarResources: JarResources maps all resources included in a Zip or Jar file. Additionally, it provides a method to extract one as a blob.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	debugOn
private Hashtable	htJarContents
private Hashtable	htSizes
private String	jarFileName

Constructor Summary

Constructors

Constructor and Description
JarResources(String jarFileName) creates a JarResources.

Method Summary

Modifier and Type	Method and Description
private String	dumpZipEntry(ZipEntry ze) Dumps a zip entry into a string.
byte[]	getResource(String name) Extracts a jar resource as a blob.
private void	init() initializes internal hash tables with Jar file resources.
static void	main(String[] args) Is a test driver.

Methods inherited from class Object

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

Field Detail

debugOn

private boolean debugOn

htSizes

private Hashtable htSizes

htJarContents

private Hashtable htJarContents

jarFileName

private String jarFileName

Constructor Detail

JarResources

public JarResources(String jarFileName)
             throws IOException,
                    FileNotFoundException

creates a JarResources. It extracts all resources from a Jar into an internal hashtable, keyed by resource names.

Parameters:

jarFileName - a jar or zip file

Throws:

IOException

FileNotFoundException

Method Detail

getResource

public byte[] getResource(String name)

Extracts a jar resource as a blob.

Parameters:

name - a resource name.

init

private void init()
           throws IOException,
                  FileNotFoundException

initializes internal hash tables with Jar file resources.

Throws:

IOException

FileNotFoundException

dumpZipEntry

private String dumpZipEntry(ZipEntry ze)

Dumps a zip entry into a string.

Parameters:

ze - a ZipEntry

main

public static void main(String[] args)
                 throws IOException

Is a test driver. Given a jar file and a resource name, it tries to extract the resource and then tells us whether it could or not. Example Let's say you have a JAR file which jarred up a bunch of gif image files. Now, by using JarResources, you could extract, create, and display those images on-the-fly.

     ...
     JarResources JR=new JarResources("GifBundle.jar");
     Image image=Toolkit.createImage(JR.getResource("logo.gif");
     Image logo=Toolkit.getDefaultToolkit().createImage(
                   JR.getResources("logo.gif")
                   );
     ...
 

Throws:

IOException