Back in 1995 when I started programming in Java, there was a lot of manual work that is now done automatically. Updating classpaths, remembering what order to compile large projects in (remember,
maven hadn't been invented either, and
make isn't easy to use).
The class libraries were a smaller set of things to know. Instead of auto-complete, I had a large poster with Every Single Class And Method on the wall of my office at Javasoft; and unless it was one of the fiddly utilities in java.io, I pretty much knew them all. The advantage was that I used the class I meant, rather than finding something that looked good by name and then finding out it didn't have the right functionality. But mostly I prefer auto-complete and richer libraries.
Refactoring tools are the other enormous change. Changing a variable name was an ten minute project, rather than ten seconds; and changing class structure took you all day. Extracting an important superclass? Better budget a few days!
There was a lot of "Compiling!" And then coming back to find out you forgot to include some class in an obscure directory somewhere.
Producing a release was also a pain in the neck. Remembering the syntax for the MANIFEST file, or for
jar at all. Where did my resources go?
Finally, integration with version control (CVS or SCCS) was non-existent, so you had to be a SCM expert as well as a Java expert.
Summary: Lots of tasks that are now automated had to be done by hand, and you had to master a bunch of auxiliary skills that nowadays you can mostly ignore.