I am currently trying to install DrJava plug-in in Eclipse Oxygen and I always get an error saying "could not find jar file" even though I opened it using the Install New Software in the Help menu...
I think I have tried everything I could but it does't seem to work...
or is there any better plugin in eclipse that has an interaction pane?
The DrJava Plug-in for Eclipse is an Eclipse 2.x plug-in which are not supported anymore. Therefore, it is not possible to install the plug-in in a current version of Eclipse.
A very similar functionality is built in the Eclipse Java IDE as Java Scrapbook Page (File > New > Other...: Java > Java Run/Debug > Scrapbook Page) and for debugging as Display view (similar to select an expression in the Java editor and hit Ctrl+U or right-click and choose Execute).
In Java 9, there is also a so-called JShell.