For Spring I find https://bootify.io https://bootify.io does a great job of generating DB, models, CRUD frontend+backend. Not open source but the basic variant

For Spring I find https://bootify.io https://bootify.io does a great job of generating DB, models, CRUD frontend+backend. Not open source but the basic variant is free (and I mean really free to use, no registration, just use it) and the code generated is reasonable for further development.