Jar Problem

[k4ghg]

Hi - I have a JAR file that uses data files and two zipped files, but I can not get them to work. Every thing works file in my IDE when I work with JAR's files and the zipped files.

At first I included all the files in the JAR and used a Manifest file:

Main-Class: folder.mainName
Class-Path: folder.zipFile_1.zip folder.zipFile_2.zip

First the JAR would not read the dat files in the JAR. It did work when I put the data files in the JAR's folder.

a) Is there a way to get the JAR to read text files within the JAR.?


The JAR would not access the zip files. I reied putting them out side the JAR and changed the Manifest file without too much luck. Here is the file:

Main-Class: folder.mainName
Class-Path: zipFile_1.zip folderFile_2.zip

b) How can I get the JAR to read/use the resources in the zipped file?

Any help/suggestions would be appreciated. Thanks... Ronnie

 

[stefanwagner]

Datafiles aren't search in the classpath.
That's the reason why it is called classpath, and not datapath.

In java.util. you find classes for reading from zip-files.
Use relative paths to find the zip-file, and make a startscript, to change to that well-defined base-dir, before starting your app.

Or use a property:

java -DDATADIR=/home/foo/.fooapp/datadir -jar fooapp.jar

seeking a job as java-programmer in Berlin:

http://home.arcor.de/hirnstrom/bewerbung

 

[k4ghg]

Thanks Stefanwagner, I managed to get the JAR to access the zip files by putting them in the JAR's folder.

There is something that I am not clear at JARs. Does the "Class-Path" reffer to external programs or to the JAR itself? That is if lets say my JAR is in c:\ can I use d:\ for a "Class-Path"?

Does the zip classes in java.util also handle JAR files?

Thanks...Ronnie

 

[stefanwagner]

The class-path inside a jar-Manifest refers to outer classes or directories or jar-files.
You may not access nested jar-files that way - for such behaviour you have to replace the classloader by a specialpurpose classloader.
I once found some in the web, but didn't get warm with the idea of using a different classloader.

I never used the zip classes to handle jar files in my code, but to zip a directory foo, I use jar:

jar -cfM foo.zip -C foo .

and never saw a problem when using zip to unzip jars or jar to unzip zips.
jar-files are - in my opinion - zip files, only by default (without using the 'M' switch) a manifest is added, but that's not a problem for zip-tools.

seeking a job as java-programmer in Berlin:

http://home.arcor.de/hirnstrom/bewerbung