[java] How to get absolute path to file in /resources folder of your project

Assume standard maven setup.

Say in your resources folder you have a file abc.

In Java, how can I get absolute path to the file please?

Create the classLoader instance of the class you need, then you can access the files or resources easily. now you access path using getPath() method of that class.

 ClassLoader classLoader = getClass().getClassLoader();
 String path  = classLoader.getResource("chromedriver.exe").getPath();
 System.out.println(path);

You need to specifie path started from /

URL resource = YourClass.class.getResource("/abc");
Paths.get(resource.toURI()).toFile();

To return a file or filepath

URL resource = YourClass.class.getResource("abc");
File file = Paths.get(resource.toURI()).toFile(); // return a file
String filepath = Paths.get(resource.toURI()).toFile().getAbsolutePath();  // return file path

The proper way that actually works:

URL resource = YourClass.class.getResource("abc");
Paths.get(resource.toURI()).toFile();

It doesn't matter now where the file in the classpath physically is, it will be found as long as the resource is actually a file and not a JAR entry.

(The seemingly obvious new File(resource.getPath()) doesn't work for all paths! The path is still URL-encoded!)

There are two problems on our way to the absolute path:

1. The placement found will be not where the source files lie, but where the class is saved. And the resource folder almost surely will lie somewhere in the source folder of the project.
2. The same functions for retrieving the resource work differently if the class runs in a plugin or in a package directly in the workspace.

The following code will give us all useful paths:

    URL localPackage = this.getClass().getResource("");
    URL urlLoader = YourClassName.class.getProtectionDomain().getCodeSource().getLocation();
    String localDir = localPackage.getPath();
    String loaderDir = urlLoader.getPath();
    System.out.printf("loaderDir = %s\n localDir = %s\n", loaderDir, localDir);

Here both functions that can be used for localization of the resource folder are researched. As for class, it can be got in either way, statically or dynamically.

If the project is not in the plugin, the code if run in JUnit, will print:

loaderDir = /C:.../ws/source.dir/target/test-classes/
 localDir = /C:.../ws/source.dir/target/test-classes/package/

So, to get to src/rest/resources we should go up and down the file tree. Both methods can be used. Notice, we can't use getResource(resourceFolderName), for that folder is not in the target folder. Nobody puts resources in the created folders, I hope.

If the class is in the package that is in the plugin, the output of the same test will be:

loaderDir = /C:.../ws/plugin/bin/
 localDir = /C:.../ws/plugin/bin/package/

So, again we should go up and down the folder tree.

The most interesting is the case when the package is launched in the plugin. As JUnit plugin test, for our example. The output is:

loaderDir = /C:.../ws/plugin/
 localDir = /package/

Here we can get the absolute path only combining the results of both functions. And it is not enough. Between them we should put the local path of the place where the classes packages are, relatively to the plugin folder. Probably, you will have to insert something as src or src/test/resource here.

You can insert the code into yours and see the paths that you have.