[Solved] Loading LWJGL natives - (Running a .jar in linux)

Newbie & Debugging Questions
#1

Hello, I just wondered if anyone could help me with this :clue:. I usually develop on Win 8 but want to make sure my jar files run on Linux also.

I can make a Display using LWJGL and run it on eclipse and export a .jar to run on windows and everything runs as expected. If I take the same project and run it in eclipse on Linux Mint it runs just the same, but it will not run as a .jar file. (I can even export the jar file in Linux Mint and then run it on Windows)

I have the natives in a folder called “natives” (for each OS in the same folder) in the same directory as the game.jar.

I use

System.setProperty("org.lwjgl.librarypath",new File("natives").getAbsolutePath());

Or

System.setProperty("org.lwjgl.librarypath",System.getProperty("user.dir") + "/natives/");

to load the natives. I give the permissions to the Jar file to run and use the OpenJDK 7.
Does anyone know what I can do to get it working on both windows and Linux?

Cheers :wink:

#2

I just fired up a Linux Mint VM and using both ways worked. Are you sure the Linux natives are included?

#3

I just re-downloaded to be sure. But as it works in eclipse in Linux mint I thought that probably couldn’t be the problem. Also libGdx works fine as well, which is really confusing.

Well I don’t know why it wont work, but for now I just keep coding in Windows and worry about running on linux later, my priority is running on Windows/Android first anyway so I’m not too worried. :clue:

#4

Could you send me a test example that doesn’t work on Linux?

#5

Ok I sent you the file but in the meantime I found out that I can run it if I open a terminal and type

java -jar Game.jar

::slight_smile:
I didn’t know this is how to open jar files on linux as I’m a complete linux noob. I was expecting to be able to write click and ask to open with the OpenJDK7 as I can for other Jar files.
So the thing is, it does work but I don’t think it is really easy to do for beginners(to linux), such as myself and I want my programs to open in a very user friendly way. Is there a way of making a single click file that would open the program for a non developer?

#6

Two answers here:

  1. This answer is only for your own usage. It makes using .jar files easier:
    [this guide is for KDE]
    [x] Right-click on any jar file in the file explorer (dolphin for me)
    [x] Click on the ‘File type options’-button
    [x] Click ‘Add’
    [x] Type in ‘java -jar’, Check ‘Run in terminal’ if you want it to run in terminal… (obviously)
    Hope this helps for you, I’ve seen this techneque fail somehow… :frowning:

  2. How to distribute .jar files, to make them available to other linux users:
    [x] create a new file named ‘run.sh’ in the same directory as your .jar file
    [x] open it with a text editor
    [x] write this into the file:


#!/bin/bash
java -jar YourJarName.jar

[x] close the editor, right-click the file and click ‘Properties’. You might search a little on GNome / Unity, but on KDE it’s like this: Under the tab ‘Permissions’ check ‘is executable’

If you now double-click the .sh file, the jar starts.

I’m sorry. There no other way. It’s pretty ugly in linux atm.

#7

Too many environments fail to set up the associations for .jar, or change them capriciously (read: Windows) to rely on an executable .jar as your sole distribution mechanism. At the very least, you need to ship a wrapper script, and if you want it to be polished, make it a genuine clickable installer.

#8

Yeah I can confirm that it doesn’t work when double clicked. Apparently neither did my test jar. It only works from the command line. Either way, it’s best not to distribute a JAR file and do like the others said :slight_smile:

#9

You could also use JarSplice, will wrap your jar and natives into a single shellscript (.sh) for linux, exe for windows and an .app for OS X.

#10

@matheus23 Thanks your suggestions. I can’t do the first one as the options aren’t there in linux mint. The second one is just what I need 8). When I double click the script I get the options to ‘Run in Terminal’ ‘Display’ Cancel’ or ‘Run’ which is actually better then just running the jar.
I hadn’t considered that actually having the terminal would be a useful, now I can have some useful feed back at run time from the final program and not just in the IDE. ;D