With Java 9 comes JShell, the first official Java Read-Eval-Print-Loop (REPL). The Takipi blog has a nice article out, just in case you don’t know nothing about it. Read it here: Java 9 Early Access: A Hands-on Session with JShell – The Java REPL.

I’m gonna show you today a short screen cast using the current nightly build from the free and Open Source IDE NetBeans. NetBeans allows to run JShell not only with JDK 8 but also agains an opened Maven project, containing all the dependencies from your POM file and the classes of your project.

The first part is a recap what JShell REPL is all about. In the second part, I’m gonna use my DOAG 2016 project. The project is a database centric project using jOOQ for creating database queries.

I’m gonna open up a JDBC connection to a local Oracle Database and execute some queries, from really simple ones to the ones I used in this talk:

What is it good for? In this case I can design complex database queries, try them out, having all the NetBeans features and tools at hand without going through a save / compile / reload whatever cycle. The NetBeans nightly has a lot of rough edges, sure, but you see the potential here.

I also tried starting up Springs application context, but that didn’t work for me yet. That would also incredible useful, especially in regard to generated Spring Data repositories.