for the 1st case using jdeveloper tas
ks feature is not really a too good thing unless. But for the 2nd case where you are whole and sole of some piece of code and have to track all todos for a shorter duration then there is a brilliant feature in jdev called tasks.
To enable it you need not to do anything. Simply write at //TODO
anywhere in the code editor. And, jdeveloper will automatically mark it as a todo item.
To see or manage all your TODO's you can go to menus-->View -->Tasks and a small pane will appear in the bottom showing all the TODOs.
You can update existings ones, delete, change priority and add new as well. Double click on any todo willl take you to the marked position.
You can list the task for the current project or app or file only. There is useful filtering option available which can be used to set custom filter like show all which has a due date tomorrow (u need to put actual date). etc.