Vaadin lets you build secure, UX-first PWAs entirely in Java.
Free ebook & tutorial.
Help with my learning
I'm studying vaadin since the beginning of this month and make all examples and stuff from the site, now I'm trying to make a web-app with JPA and mysql, but I'm having some troubles with how to create the code structure. i'm asking if someone can send me a link or a vaadin project to me for study how the layers works, because i'm looking at internet and find a lot of frameworks to use with vaadin, i just want to make a simple CRUD application with a database. And in the book of vaadin they only shows how to do but I can't make it right all together like a good MVC project.
If it helps, I have a simple Vaadin app that uses JPA to save info and SQLTable to retrieve it here:
Here's another that uses JPA for more of the CRUD operations:
Note that in the second one, all the links to code examples are going to be broken (Oracle moved the blog from sun.com to oracle.com). So to get the files you'll have to change 'sun.com' to 'oracle.com' in the URLs.
In both of these examples, I use a full Java EE container (compared to Tomcat, which is only the servlet container) because the code is much simpler. If you're using Tomcat, then you'll need to replace the EJB with a simple Java class that handles the JPA stuff. I can point you to an example if you'd like that.
There are many ways to do all this, but a Vaadin app is a Java web like any other at the container level. So whether you like MVC, or presentation/boundary/model, or whatever else, a Vaadin app fits in well. (Side note: a minor point about Vaadin that I love is that there's an obvious servlet entry point that creates instances of Vaadin application objects. That makes it ridiculously simple to get managed objects like EJBs into a Vaadin app.)