Historically it was fairly common. I wouldn't say it was standard, but it happened often enough to notice. There's a bunch of reasons that come together to cause that.

During the explosion of the web, enterprises moved much of their development into web solutions using an existing workforce that had skills in different technologies - often client-server desktop-to-RDBMS tech. Java was a popular choice for these new projects. Those developers would range in their general aptitude - some were quite good, some weren't - but they all came onto these projects with existing skills and knowledge in patterns and architectures that weren't particularly well aligned with web development. They were expected to adapt and deliver at pace consistent with their previous projects. So they did what they could to get the job done, even though that meant that their solutions were not well suited to the web environment. That doesn't have a lot to do with Java specifically, except that it was a common language for that situation. It was far more common for enterprises to take VB/PowerBuilder/Delphi/etc Devs and move them into Java than something like PHP.

But Java was more likely to produce this horrible implementation for a couple of reasons.

Firstly, as a general purpose language (that also happened to have decent web capabilities​) it was easy to design​ an application using your traditional patterns and then just shoe-horn the web UI on top. You were far less likely to do that in a web-oriented platform like PHP or ColdFusion (!).

Secondly, the Java servlet spec makes sessions really easy (because it stores standard, stateful, Java objects) and didn't offer a lot for managing complex page state. You could spend several days trying to build something to page through database search results with query parameters, only to find that the back button broke your design. Or you could just throw it all into the session, and call it "done".

That probably peaked about 15 years ago, but inertia is a strong force, particularly in government and large enterprises. Some of those developers are probably still working like that. Some of them trained others. And many others know that it's a bad design, but there's no budget to fix it.