Reading a resource file from within jar
I would like to read a resource from within my jar like so:
File file;
file = new File(getClass().getResource("/file.txt").toURI());
BufferredReader reader = new BufferedReader(new FileReader(file));
//Read the file
and it works fine when running it in Eclipse, but if I export it to a jar the run it there is an IllegalArgumentException:
Exception in thread "Thread-2"
java.lang.IllegalArgumentException: URI is not hierarchical
and I really don't know why but with some testing I found if I change
file = new File(getClass().getResource("/file.txt").toURI());to
file = new File(getClass().getResource("/folder/file.txt").toURI());then it works the opposite (it works in jar but not eclipse).
I'm using Eclipse and the folder with my file is in a class folder.
Rather than trying to address the resource as a File just ask the ClassLoader to return an InputStream for the resource instead via getResourceAsStream:
InputStream in = getClass().getResourceAsStream("/file.txt");
BufferedReader reader = new BufferedReader(new InputStreamReader(in));As continued as the file.txt resource is accessible on the classpath then this approach will serve the same way regardless of whether the file.txt device is in a classes/ directory or inside a jar.
The URI is not hierarchical happens because the URI for a store within a jar file is going to look something like this:
file:/example.jar!/file.txt. You cannot read the entries within a jar (a zip file) like it was a plain old File.