Well, I am also new to ROS and I'm not sure whether this answer will be helpful. But when I use rospp and rospy, I use jetbrains IDES: CLion and Pycharm respectively. What I did was,
- I opened a terminal in my working directory and sourced it.
- From the same directory, I moved into IDE's installation directory and start the IDE from command line.
eg: for CLion:
>> cd ~/catkin_ws
>> source devel/setup.bash
>>cd /home/<user>/clion-2018.3.2/bin
>> ./clion.sh
After that I can use my IDE to edit ROS packages, and most of the time, the code predictions also appeared accurately. You can try the same process for your IDE also (IntelliJ IDEA community version can be recommended for java) .
But to my knowledge, ROS specific debugging tools are not available with these IDEs. (Please correct me if I'm wrong). I always use IDE terminals to run and debug.