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

java

file-path

java-resources

classpath

byAlex Kataev·Feb 18, 2025

Feeling the need for speed? Use this snippet to get the absolute path to a resource:

String path = YourClass.class.getResource("/filename.ext").toURI().getPath();

Replace YourClass with your class and filename.ext with your resource file's name. This assumes your resource isn't part of a jar. If it's in a jar, use getResourceAsStream() instead.

Under the hood: how Java accesses resources

In Java and build systems like Maven or Gradle, resources are often bundled within the classpath. Understanding how Java accesses these resources is key to effectively working with files in your resources folder.

Highlighting file path nuances and solutions

Working with file paths in Java might lead you into a maze of challenges such as URL encoding, file vs. jar location, and cross-environment compatibility. Here's how you can make your way out:

Dealing with URL encoding

URLs can sometimes include characters that require encoding. Fetching paths directly can leave you with URL encoded paths. Get around this by turning the URL into a URI, like so:

URL resource = YourClass.class.getResource("/filename.ext");
Path path = Paths.get(resource.toURI());

Mindful resource locations

The way you access your resource depends on whether it's in a directory or jar. If it's in a directory:

File file = new File(path.toAbsolutePath().toString());

If it's in a jar, a stream would be better:

InputStream is = YourClass.class.getResourceAsStream("/filename.ext");

Embracing environment differences

Different operating systems can mean different file separators. ClassLoader.getResource ensures cross-platform compatibility.

Testing: your new best friend

Your access code might work extraordinarily well in your development environment and completely crash when packaged. So, test it, standalone and packaged.

Absolute path: real life isn't always simple

For complex scenarios, you can combine ProtectionDomain with the class location URL to navigate to the resources folder dynamically:

ProtectionDomain domain = YourClass.class.getProtectionDomain();
CodeSource codeSource = domain.getCodeSource();
URL location = codeSource.getLocation();
Path absolutePath = Paths.get(location.toURI()).resolve("../resources/filename.ext").normalize();

When your resources seem to play hide and seek by dynamically changing locations, use ClassLoader and URL manipulation to determine the path successfully.

Class loaders: the treasure map

Class loaders work like a map for your Java application, assisting with locating resources. You can access the class loader directly to get resources:

URL resource = YourClass.class.getClassLoader().getResource("filename.ext");

When using ClassLoader, start the resource path with a / which treats it as absolute within the classpath.

Minding the position of the local "treasure"

Placement of resources folder may vary depending on your project layout. It's essential to not hard-code any paths and use relative paths instead.

From URL to File System

Always check resource != null before further operations to avoid NullPointerExceptions when resources are not found. Not not checking this may prove as wise as forgetting your lunch for a treasure hunt!