Is there a way for Eclipse that will pop-up the javadoc related to the code when I press, say, Ctrl + Shift + Space, as NetBeans does ? I don't like it to open attached javadoc in external or internal web browser.
You can use F2 shortcut to show tooltip/javadoc description for the element at the cursor.
It happens in eclipse when your mouse is over the interesting element. Additionally you can open javadoc view, so the javadoc will appear into this view. It is even more convenient especially if the description is long and cannot be viewed without scrolling.
来源：https://stackoverflow.com/questions/9047291/eclipse-pop-up-javadoc