Intellij 和 cmd 的 java 项目的相对路径是否不同？

Question

I have a java assignment, and at a specific point, we have to create a new folder and write some text files there. The issue is, when testing my code on Intellij, it works fine, but when testing it on cmd, I need to change it a tad bit?

My project structure:

.../project/src/greedycomparisons  // greedycomparisons is the file where I'm creating the dir from
.../projct/data                    // the directory I want to create, to have my text files in

More specifically:

I'm trying to create the new subdirectory from a file I have inside my src folder. Therefore, the thing I tried first was:

File directory = new File("./data/");
if (!directory.mkdir()) dosth;    // nothing happens on first call
/* making the String I want as my file's name, say string */
File file = new File(directory, string);

Which works fine (on Intellij), creating the subdirectory (and the files later on) exactly where I want them to. And then, likewise, I try accessing the files I made there from another file in my src folder, by again using "./data" before the name of the file I was trying to access, which again works as expected on Intellij.

But when I tested this on cmd, I need to change the directory name to "../data" in order for the code to work, which in turn does not work on Intellij (specifically giving me a "The system could not find the path specified" error) when I change it to that. Given that I have to submit it as an assignment and I don't want any ambiguity in regards to my files, is there something more "universal" that I can try, so my code works regardless?

Answer 1

If you check your IntelliJ configuration, by clicking at the top where you have the name of the file you are executing, you can click on Edit Configurations, and you will see one of the fields you can configure, called "Working directory".

IntelliJ is smart enough to set it to your project folder, outside the /src folder, because it is not good practice to write data inside your /src folder which should only have source files, unless they are resources you want to commit with your code.

On the other hand, when executing it from cmd , your working directory is just where you are trying to run the compiled program from. You haven't specified in which folder you are in when doing so, but most probably you are inside some subfolder that has the classes, which is why you needed to do the .. .

If you package your classes in a .jar file, the way IntelliJ made it should work. If you run your .jar file with java -jar myjarfile.jar and the ./data folder is at the same level, then it would work.