There is a java program in the folder

`Downloads/jason/src/demo/de/l3s/jason/testfile.java`

I can compile it with `javac testfile.java` (while in that directory)
Resulting in `testfile.class`. 

But I cannot run this file by typing `java testfile` 
If I manage to run the file, it cannot locate any components of the file.

The `testfile.java` contains

```
 package de.l3s.jason.demo;

 import java.net.URL;

 import de.l3s.jason.extractors.ArticleExtractor;

 public class testfile 

```

And then a couple of lines of code. 

How do I tell Java where to look for these components? 

I have added several jar files to the classpath (per the documentation) by copying them directly into `home/usr/lib/jvm/java/jre/lib/ext`

Aside from that, the classpath works fine with "java" and "javac" working from anywhere.

I couldn't get this to work on Windows either, which is why I switched to linux.