How to know a jar file directory

Question

I have a text editor maked with Swing. All code of my program is inside a myProgram.jar
When a user click on a txt file, this file is open with myProgram.jar.
When myProgram start it's create a properties file.
This properties file is created with this code:
String path = System.getProperty("user.dir") + File.separator + "MyFile.txt";
File f = new File(path);
The path is not the path which i want. The properties file must create in the same dir where is stored myProgra,.jar and not in user.dir. How i can know which is the dir where the jar is stored?
path = ?

Answer 1

You're getting a null because the class file cannot be located. In other words, you haven't provided the correct info or the info in the correct format. Use the jar command with the xfv options to get the proper info. For example:
jar -xfv myProgram.jar
where myProgram.jar is the name of your jar file.
In the following example, if I wanted the URL for Chart.gif under a subdirectory named images, I would do this:
URL jarPath=this.getClass().getClassLoader().getResource("images/Chart.gif");
D:\AOKabc\prod>jar -xvf aokabc.jar
extracted: images/Chart.gif
extracted: images/Tile.jpg
extracted: images/Back_.gif
extracted: images/Forward_.gif
extracted: images/invalid32x32.gif
extracted: images/image-failed.gif
extracted: SysParams.properties
Ok?
;o)
V.V.