If you try the newest version 12.2.1.2 (or maybe earlier versions too) you see, that your managed server does not restart
If you work with JDeveloper 12.1.3 and you work with code editor save actions the order of actions could be relevant for you. For an example you use lot of asterisk (*) imports and JDeveloper should edit the code to import only classes that you actually use in the code.
If you work with JDeveloper 12.1.3 you may missing the return type of methods in completion insight.