During my studies a spring boot, I found an article very cool. It is a kind of guide for navigating topics inside around world of java.

The image above is focused on spring boot, but in the link below is possible to access the roadmap completely, navigate by front-end, databases, ide, rest between other topics important to dev.

Link: https://coggle.it/diagram/X-dDo1Qdf7DCP2zg/t/how-to-master-java/a3c8bede6822097b7f3c6340b82eabd7986c57af4d42f11c122d5065479d5928

Also found this other link, another kind of roadmap, with various topics, such devops, front, back, java, react. It's worth a look :)