Can I open a REPL in the context of a Spring Web Application?

Question

I'm working on a web application based on Spring MVC and Hibernate on Tomcat 8 (both for deployment and local development). The IDE is Spring Tool Suite (which is based on Eclipse).

I want to open a REPL (read-eval-print-loop, like Groovy's, Python's, Ruby's, etc) in the context of my application (while it's running on Tomcat locally), to speed up development by shortening the code -> test feedback loop.

That is, I want to be able to open a shell in the command line (or inside Eclipse) and do something like:

ClientDAO clientDAO = getAutowiredDAOFromSpringSomehow();
Client client = clientDAO.findByID(100);
client.setName("Another name");
clientDAO.save(client);

I can work around this a bit by setting a breakpoint somewhere in a controller and use Eclipse's debugger Display tab to execute arbitrary code, but this is a bit impractical and uncomfortable.

I'm open to using Groovy or Scala's shell if it's more convenient (I obviously still need access to my objects, though).

What are my options?

Answer 1

You may be able to do it using Spring Shell, JShell or BeanShell

Here's a project to embed a repl in an android app using BeanShell

Answer 2

I don't know if it's useful for your use-case but theoretically it should be possible to do this using CRaSH. It's a Shell like Bash on Linux but for your Java-Application and it's possible to create your own commands.