How to get the path of a running JAR file?

Advanced considerations

Before applying the solution, delve into the following nuances to enhance code resilience and cross-compatibility:

Addressing special characters

It's possible that your paths may contain a few exotic characters. Decode such paths using URLDecoder:

String jarPath = URLDecoder.decode(YourClass.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath(), "UTF-8");
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Respecting SecurityManager limits

Keep guard for a SecurityException, a lurking adversary if a SecurityManager denies access to the ProtectionDomain.

Addressing non-file sources

Bear in mind that the response from getProtectionDomain().getCodeSource() may act coy if the class was loaded from a non-file source, like a JAR file across the network.

Bulletproofing code

While striving to get the JAR file path, you might encounter a few turbulences. Here's how to navigate them:

URISyntaxException handling

Steer clear of erroneous URI structure by wrapping it up in a try-catch block:

try {
    String jarPath = YourClass.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath();
} catch (URISyntaxException e) {
    // You had ONE job, URL!
}
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Absent file resource

When leaning on getClass().getResource("YourClass.class"), it might happen that the resource mysteriously disappears. Make sure that the class names are quoted correctly.

Environment-specific guidelines

Each runtime environment is a unique beast. Here's how to tame them:

Dependable JAR file logic

Ensure consistent JAR paths across multiple environments by placing the retrieval code within the JAR file itself.

Universal compatibility

The solutions demonstrated work across platforms. They remain unfazed by the operating system and JAR location — truly the 'Java' of solutions!

Multi-environment testing

To make your solution unbreakable, test the retrieval code in various environments. Because, you know, it's always fun to see things messing up in production.

Third-party libraries like SciJava

Ease out resource handling when using SciJava Common by leveraging getLocation() and urlToFile(), which are the equivalent of GPS for your JAR files.

Community insights

Stack Overflow is a treasure chest of pragmatic wisdom. Let's distill the best:

Top troubleshoots

Learn from the missteps of others who faced issues like incorrect URI manipulation or muddling URIs and File paths.

Compiler-specific quirks

Understand that depending on which compiler or build tool (like Maven or Gradle) you're using, you'll have to tailor how you fetch the JAR's path.

Proxy reflection

To get access to JAR paths, you may need to employ some Java reflection. Best understand the nuances of commands like getProtectionDomain() from expert discussions before you dive in.