When using jetty:run, CSS and JavaScript files are locked – how can I fix this?
Jetty buffers static content for webapps such as html files, css files, images etc and uses memory mapped files to do this if the NIO connectors are being used. The problem is that on Windows, memory mapping a file causes the file to be locked, so that the file cannot be updated or replaced. This means that effectively you have to stop Jetty in order to update a file. The problem is explained more in Jetty’s documentation.
