If you've already done this, or if you know how to do this, skip this step in the instructions. Java is useful for lots of other things, so you may already have it on your system (or may later use it for things other than JV_Map.) Note that if your web browser supports Java, this does not necessarily mean you have the necessary tools to run stand-alone Java applications on your machine.
Java can be a pretty large download, but usually installing it is quite easy.
Note that there are bugs in all the implementations of Java 1.3.0 out there, which can lead to memory leaks that could potentially cause a running Java program such as JV_Map to grow and grow. The beta of Java 1.3.1 seems to have fixed this problem, and presumably it's only a matter of time before a public release of Java 1.3.1. Earlier versions of Java (including Java 1.2.2 and Java 1.1.8) don't have the problem.
Installing Java in Linux is easy. Here are a handful of places to look:
Many recent Macintosh systems actually come with a Java runtime environment. If you don't seem to have it, or if you have any interest in having the full Java programmer's kit (which is necessary to turn standard Java applications into clickable-runnable applications on the Mac), look at the MRJ Java SDK for the Mac.
Download the Java Runtime Environment (JRE) from Sun's Java download page. Choose your version:
In many cases, I'm sure it can be done, but I don't know where to find Java for Unix systems other than Linux and Solaris....
Download the latest version of JV_Map (available under the GPL; see the download section on the main page for the source code):
Put this file somewhere where you can get to it from a command line. That's all! You're done! (You don't even have to unzip the .zip file.)
Download both of these files. The second one is a launcher which should hopefully allow you to run the first. (The file is a StuffIt archive, which I'm told is ubiquitous on the Mac.)
If you have the savvy to run JBindery with the Mac MRJ Java SDK, then you can just download the .zip file and create your own launcher. Thanks to Jim Adams for providing the launcher!
If any of this doesn't make sense, then skip it!
If you are clever, on any platform you can probably create a clickable-runnable launcher. I use the "floating J-on-green-hexes" icon that's all over these pages as an icon on my Gnome panel. The command line to run may be:
java -cp <location>/jv_map_0.10.8.zip rknop.jvmap.JV_Map
This command line should work with Sun's Java 1.2 or 1.3. Java 1.1.8 uses "-classpath" in place of "-cp", and needs to have the system class locations appended as well. Contact me if you have trouble getting the program to run with your Java JRE.
If you are a Java wonk, then you may just want to either put the .zip file somewhere in your classpath, or unzip it somewhere in your classpath. Don't worry about it if you didn't understand what I said. If you do do this, then you also know enough to modify the running step below.
Since JV_Map was written to be compatable with V_MAP, the best place to start looking for JV_Map compatable maps and counter sets is Todd Zircher's V_MAP home page. See the Links and the Support Section on the main JV_map page for other places to look.
Note that, in particular, Ogre and GEV maps and counter sets are included with the main V_Map archive. You may have to be a little creative in order to decompress them, however. E-mail me if you have questions, or see the support section of the main JV-Map page.
On a command line system (Windows and Unix):
Go into the directory where you downloaded the JV_Map .zip file and run the following command:
java -cp jv_map_0.10.8.zip rknop.jvmap.JV_Map
(Note that on Windows you will have to open up a MS-DOS shell to run this command.) Obviously, you must have succesfully installed Java (the Java Runtime Environment mentioned above) for this to work.
On other systems, run the clickable launcher that either you created, or you downloaded from here.
Java will open a little window that gives you a few commands. The only ones that currently work are exiting JV_Map, and reading an existing VMP file. (You must either create one by hand with a text editor, or start with a sample or one created by V_Map.)
IMPORTANT NOTE: Not every .VMP file written by V_Map will work unmodified with JV_Map! You may need to either get your opponent to write out a different .VMP file, or you may need to edit it with a text editor. More often, you will just need to rename the names of your image files to match what is expected from the .VMP file. Some things in particular to look out for:
As of version 0.9.9, JV_Map supports BMP files in addition to GIF and JPEG files. V_Map, I believe, only supports BMP files. This means that if you have an opponent using V_Map, you're safest always just using BMP files, assuming you have a recent version of JV_Map. If you and your opponent are both using JV_Map, then you will find that both GIF and JPEG files compress a lot better and waste much less disk space than do BMP files....
Theoretically, the VMP 1.5 file format allowed images to be specified with paths in addition to filenames. However, this would not be compatable between V_Map and JV_Map, and things really only worked if the image files for the maps and counter set were in the same directory as the VMP file. As of VMP 2.0, the spec requires that the images be in the same directory as the VMP file.
Java may be case sensitive! It certainly is on Linux. I'm not sure that Windows is case sensitive, so the comparisons of the image filenames and the filenames listed in the .VMP file may not match. The easiest way around this is to just rename your image files to exactly match what you see on the MAP and TILES lines in the .VMP file. (Just "more" the .VMP file, and look for the lines MAP and TILES to figure out what image filenames that JV_Map will be looking for.)
Even though your web browser may support Java, you cannot run JV_Map from within Netscape or another web broswer! Web browsers support Java applets. JV_Map is written as a Java application, not an applet, becuause some of the security restrictions of Java applets were too severe (specifically, the prohibition on loading and saving files from the local filesystem).
If you're confused about JV_Map, having trouble getting it working, or get it working on a platform I haven't listed below, please let me know. Send me E-mail at firstname.lastname@example.org.
Last updated 2001-February-17
This page is copyright 2001 by Robert A. Knop Jr. (email@example.com).