How to make Jetty dynamically load "static" pages
I am building Java web applications, and I hate the traditional "code-compile-deploy-test" cycle. I want to type in one tiny change, then see the result INSTANTLY, without having to compile and deploy.
Fortunately, Jetty is great for this. It is a pure-java web server. It comes with a really nice maven plugin which lets you launch Jetty reading directly from your build tree -- no need to package a war file or deploy. It even has a scanInterval setting: put this to a non-zero value and it will watch your java files and various config files for changes and automatically re-deploy a few seconds after you make a change.
There's just one thing keeping me from nirvana. I have javascript and css files in my src/main/webapp directory which just get served up by Jetty. I would like to be able to edit these and have the changes show up when I refresh the page in the browser. Unfortunately, Jetty holds these files open so I can't (on Windows) modify them while it is running.
Does anyone know how to make Jetty let go of these files so I can edit them, then serve up the edited files for subsequent requests?
Answer
Jetty uses memory-mapped files to buffer static content, which causes the file-locking in Windows. Try setting useFileMappedBuffer for DefaultServlet to false.
Troubleshooting Locked files on Windows (from the Jetty wiki) has instructions.