I have developed a simple plugin to view and edit jrxml (jasper report source files) in IntelliJ Idea.
It's in a very early stage and currently, only support auto-complete and syntax highlighting only. I will develop some other advanced features in the near future. (Eg: create new .jrxml files from the context menu, compile .jrxmls files into .jasper files, etc.
Please contribute and report if you found any bugs.