How to get a path to a resource in a Java JAR file

Question

I am trying to get a path to a Resource but I have had no luck.

This works (both in IDE and with the JAR) but this way I can\'t get a path to a file, only the file

Answer 1

A File is an abstraction for a file in a filesystem, and the filesystems don't know anything about what are the contents of a JAR.

Try with an URI, I think there's a jar:// protocol that might be useful for your purpouses.

Answer 2

This is deliberate. The contents of the "file" may not be available as a file. Remember you are dealing with classes and resources that may be part of a JAR file or other kind of resource. The classloader does not have to provide a file handle to the resource, for example the jar file may not have been expanded into individual files in the file system.

Anything you can do by getting a java.io.File could be done by copying the stream out into a temporary file and doing the same, if a java.io.File is absolutely necessary.

Answer 3

private static final String FILE_LOCATION = "com/input/file/somefile.txt";

//Method Body


InputStream invalidCharacterInputStream = URLClassLoader.getSystemResourceAsStream(FILE_LOCATION);

Getting this from getSystemResourceAsStream is the best option. By getting the inputstream rather than the file or the URL, works in a JAR file and as stand alone.

Answer 4

When in a jar file, the resource is located absolutely in the package hierarchy (not file system hierarchy). So if you have class com.example.Sweet loading a resource named "./default.conf" then the resource's name is specified as "/com/example/default.conf".

But if it's in a jar then it's not a File ...