Basic application deployment specific questions

Question

I have some questions related to application deployment. Following this tutorial, I am able to create an executable 'jar' file and deploy it to another computer. So the basics work for me, however ...
1.
In order to make the application running on different computer, I manually need to copy ~8 specific files (firebird database dll's) in directories like:
c:\Program Files\Java\jre6\bin
c:\Windows\system32
If i do so, everything works fine. I did not test this yet, but I believe, IzPack software will be able to help me with this. The problem is, how do I set the destination path for those files on destination computer? This path can vary on different computers, so this path can't be hardcoded. Besides, is it normal to place application specific files into those directories?
2.
My application uses relative references to files, e.g.:
static String DATABASE_FILE_NAME = "software.fdb";
static Database _firebirdDB = new Database(DATABASE_FILE_NAME);If i execute application like this:
c:\myApplication\java -jar "NameOfJar.jar", I get a bunch of exceptions, because my database file 'software.fdb' can't be located.
If I however execute application like this:
c:\Program Files\Java\jre6\bin\java.exe -jar "NameOfJar.jar", then everything works all-right.
Obviously, my application depends on current working directory, when it's executed. How can I avoid this?
Thanks for help in advance,
Juraj

Answer 1

durino13 wrote:
1.
This may be silly question, but where can I find more information about 'installing complex applications with native libraries'? I even don't know, what to search google for ..
For instance, i have JAVA installed on my PC, but I don't have env. variable %JAVA_HOME% set. So I can't rely on this .. Really, the problem is that Java is designed to be platform-independent, but you're trying to use dlls which are native to each platform. To get the platform independence, Java generally doesn't know about any native libraries. If you have an application which depends on them, it's your responsibility to [get them to a place where Java can find them|http://www.inonit.com/cygwin/jni/helloWorld/load.html].
When you have a standard installer for an application, it's making sure the libraries are in the right place. If they aren't, it has to find a way to put them there. Sometimes the app will just keep a copy in its own directory, so that it doesn't have to install it into an OS directory. The setup.exe program is specially designed to handle this kind of thing on Windows.
Java, on the other hand, doesn't know you're on Windows. It could care less. All it knows is that it has Java code, and it's running in a JVM. If you explicitly tell it to load a system library, it does it and you can access it with JNI. But it still couldn't care less that you're on Windows.
Like I said, I've worked with packages that are mostly Java but have some native code. Usually, what it comes down to is the installation instructions saying, "Put this DLL in the Java path." Sometimes they have a nice little installer that does it for you, or can try to use JAVA_HOME and asks you where to put it if it can't find it. But you are absolutely right -- you can't rely on it because Java doesn't care you're on Windows. You should have JAVA_HOME from the Java installer, but it really doesn't care. It's your responsibility to package it in such a way that it works.
3.
It is a bit strange, anyway. Normally, when I see application packages, I see something like 'setup.exe' bundled with dozens of 'dll's' .. Is it correct to put everything under 'jar'?Setup.exe is a Windows executable to install Windows programs. Java doesn't care that you're on Windows, so it offers JAR, an executable package format. There are some tools to make it easier for delivery on a particular platform, but I've never used them.