^{This article is written to show you how to use seppia to start up your application and how this operation can dramatically reduce  your installation and deployment efforts.}

An interesting and straight-forward way to use Seppia is as an application launcher.
Suppose you have written your java application and suppose that your application needs some third party software, let's say: 

• log4j-1.2.7.jar
• xercesImpl.jar
• jcommons-0.9.6.jar
• lucene.jar

Your application is then jarred in a file called greatstuff.jar and the entry point for your application is the class com.company.greatstuff.core.Main

As you were developing it in your system you were probably launching it by calling the jvm like this (peraphs this call was thru your favourite ide but that does not matter):

^{java -cp c:\deployment\greatstuff.jar; c:\otherstuff\opensource\jakarta\log4j\lib\log4j-1.2.7.jar; c:\java\3rd\xercesImpl; c:\java\3rd\jcommons-0.9.6.jar; c:\java\3rd\lucene-1.4\lib\lucene.jar com.company.greatstuff.core.Main}

As you prepare to deploy your application it is quite common this days to create a lib directory.
So the way to launch it becomes:

^{java -cp c:\greatstuff\lib\greatstuff.jar; c:\greatstuff\lib\log4j-1.2.7.jar; c:\greatstuff\lib\jcommons-0.9.6.jar; c:\greatstuff\lib\lucene.jar com.company.greatstuff.core.Main}

which assumes that the final user has installed it in c:\greatstuff
To ease the process of installing and running your application you probably need to provide some batches or scripts depending on the o.s. on the user's machine.

Finally it is reasonable to think that your application might need to read some property files or pass some values to the main method in order to start up properly.

We are now going to show you how we are going to simplify all of this and let the user start up your application by simply typing: 
 
^{java -cp . StartUp} 

1. Install Seppia in the directory c:\greatstuff
2. Create a directory called jars under org.seppia.bootstrap
3. Copy all of the jars (log4j-1.2.7.jar, xercesImpl.jar, ...) in it
4. Modify the StartUp.js javascript in org.seppia.bootstrap\javascripts to call your application's entry point:

       function main() 
       {
          Packages.com.company.greatstuff.core.Main.main([]);
       }
       

greatstuff
    + jars 
    + modules
         + org.seppia.bootstrap 
             + javascripts
             |       + StartUp.js
             + jars
                 +-- log4j-1.2.7.jar
                 +-- xerces.jar
                 +-- commons.jar

1. No classpath to maintain: suppose you want to replace a jar with a newer version (e.g.:log4j-1.2.8) all you have to do is to substitute the file in the jars folder.
2. No need to pass some properties or arguments to the main method. You can do so by changing the javascript:

       function main() 
       {
          java.lang.System.setProperty("greatstuff.speed","20000");
          java.lang.System.setProperty("greatstuff.frames","enabled");
          var args = [ "header:25","nogui" ]
          Packages.com.company.greatstuff.core.Main.main(args);
       }

   As you do this you might wonder whether you should not code those properties or args in the javascript. Peraphs you might want to change your javascript to read them from another file or to find them from another javascript. As you ponder over those issues you might just realize that this is the whole point of Seppia: to gain from the synergy of java and javascript, to combine java and javascript in a new powerful way only you are coming to it from a different angle.