Java execute file relative to jar

Question

I have a c# console application I will be sending commends to using Java, with the techniques described here Sending commands to a console application?

My issue is that the console application is in a folder that's in the same folder with the jar, and I can't find out how to execute a file relative to the same directory as the jar.

I tried a lot of things in Java, like

Process pr = Runtime.getRuntime().exec("runtime_libraries/consoleapp.exe");

But it says the file can't be found.

java.io.IOException: CreateProcess error=2, The system cannot find the file specified

I assumed it would be simple, but apparently it's not.

So my question is, how can I put a relative path into the Runtime exec?

@paisanco I have a C# console application which I am trying to execute from Java — Keith M, Oct 01 '15 at 04:20
yeah, you need to somehow find the path of the jar file :) maybe from `System.getProperty("java.class.path")`. It's also possible from Class/ClassLoader. — ZhongYu, Oct 01 '15 at 04:25
@bayou.io Thats kinda close, but it returns the paths to all the libraries on the classpath — Keith M, Oct 01 '15 at 04:31
@bayou.io Will it always return it with the path to the jar as the first path, or it there a possibility the order could be different sometimes? — Keith M, Oct 01 '15 at 04:33
@bayou.io How am I suppose to know which is the right path then if I can't depend on the order? — Keith M, Oct 01 '15 at 04:35
1. Verify your current running location using `System.out.println(System.getProperty("user.dir"));` and make sure it's where you expect it to be; 2. Verify the existence of the `consoleapp.exe` using `System.out.println(new File("runtime_libraries/consoleapp.exe").exists()));` — MadProgrammer, Oct 01 '15 at 04:41
I just found `System.getProperty("user.dir")` and it points to the correct directory for me. — Keith M, Oct 01 '15 at 04:44
@MadProgrammer If you want to make that an answer, I'll mark it as correct — Keith M, Oct 01 '15 at 04:45

score 1 · Accepted Answer · answered Oct 01 '15 at 04:56

When ever you're faced with this kind of issue, you need to do some preliminary checks...

Verify your current running location using System.out.println(System.getProperty("user.dir")); and make sure it's where you expect it to be;
Verify the existence of the consoleapp.exe using System.out.println(new File("runtime_libraries/consoleapp.exe").exists()));

Most IDEs allow you to change the working directory during development. When in production, you should ensure that the working directory is set correctly (for example, under Windows, you can configure the short-cuts to "start" in a specified location)

Java execute file relative to jar

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