从GNOME运行时如何获取可运行.jar文件的位置

Question

I am developing a small Java application using Swing, that is supposed to run on Windows/Linux and MacOS.

Eventually it will ship as a runnable jar with some config files in the same folder. To load them I need the path to the folder the jar is stored in within the program.
There are already a couple of threads like this one or this one.

My problem is, that all the solutions discussed there work fine, when I run the program from within eclipse or call the runnable jar from a terminal like so:

java -jar /path/to/jar/jarfile.jar

However when I click on the jar file in Cinnamon or Gnome (which is what most of the users will know to do), I do not get the correct paths. (MacOS users report the same issue)

Here is what I've tried so far and what the output is when run via double click (all those display the desired path when run from eclipse or a terminal):

ClassLoader.getSystemClassLoader().getResource(".").getPath()
Output: file:/usr/lib/jvm/java-6-openjdk-common/jre/lib/ext/pulse-java.jar!/

SomeClass.class.getProtectionDomain().getCodeSource().getLocation().getPath();
Output: ./

System.getProperty("user.dir");
Output: /home/myusername

Is there any other way to do it or am I doing something wrong when exporting the jar? Any help would be appreciated!

Cheers Nick

Answer 1

Make it simple, and use a startup script (.bat/.sh file) to run your application. This startup script will get the path of its own location in the filesystem, and pass it as an argument or system property to the Java application. This has the additional advantage of being able to pass other arguments, like the size of the heap, etc.

On windows, %~dp0 is the path of the directory containing the executed bat file. On Unix, you can use $(dirname $0) .

Answer 2

You could store all config files as resources in a jar, and copy them to files in home.dir + ".AppName/".

Painful as it is, the Preferences API , Preferences.systemNodeForPackage , seems the wisest alternative, if there is little structured config data. There is an inputStream method for import; your initial config template could be a resource in the jar.

Answer 3

Just get the class path using System.getProperty("java.class.path") and scan it for your ".jar" name. Note that path separators are OS dependent (File.pathSeparator)