Get the application's path

I've recently searched how I could get the application's directory in Java. I've finally found the answer but I've needed surprisingly long because searching for such a generic term isn't easy. I think it would be a good idea to compile a list of how to achieve this in multiple languages.

Feel free to up/downvote if you (don't) like the idea and please contribute if you like it.

Clarification:

There's a fine distinction between the directory that contains the executable file and the current working directory (given by pwd under Unix). I was originally interested in the former but feel free to post methods for determining the latter as well (clarifying which one you mean).

Solution 1:

In Java the calls

System.getProperty("user.dir")

and

new java.io.File(".").getAbsolutePath();

return the current working directory.

The call to

getClass().getProtectionDomain().getCodeSource().getLocation().getPath();

returns the path to the JAR file containing the current class, or the CLASSPATH element (path) that yielded the current class if you're running directly from the filesystem.

Example:

1. Your application is located at

    C:\MyJar.jar
   

2. Open the shell (cmd.exe) and cd to C:\test\subdirectory.

3. Start the application using the command java -jar C:\MyJar.jar.

4. The first two calls return 'C:\test\subdirectory'; the third call returns 'C:\MyJar.jar'.

When running from a filesystem rather than a JAR file, the result will be the path to the root of the generated class files, for instance

c:\eclipse\workspaces\YourProject\bin\

The path does not include the package directories for the generated class files.

A complete example to get the application directory without .jar file name, or the corresponding path to the class files if running directly from the filesystem (e.g. when debugging):

String applicationDir = getClass().getProtectionDomain().getCodeSource().getLocation().getPath(); 

if (applicationDir.endsWith(".jar"))
{
    applicationDir = new File(applicationDir).getParent();
}
// else we already have the correct answer

Solution 2:

In .NET (C#, VB, …), you can query the current Assembly instance for its Location. However, this has the executable's file name appended. The following code sanitizes the path (using System.IO and using System.Reflection):

Directory.GetParent(Assembly.GetExecutingAssembly().Location)

Alternatively, you can use the information provided by AppDomain to search for referenced assemblies:

System.AppDomain.CurrentDomain.BaseDirectory

VB allows another shortcut via the My namespace:

My.Application.Info.DirectoryPath

Solution 3:

In Windows, use the WinAPI function GetModuleFileName(). Pass in NULL for the module handle to get the path for the current module.

Solution 4:

Python

path = os.path.dirname(__file__)

That gets the path of the current module.