Eclipse Hovers
Use hover tooltip
The Java editor contains different types of hovers. Hovers provide additional information about the element under the mouse pointer. All Java editor-related hovers can be configured on the Hovers page in the preferences (type "hover" in the search box).
In the Java editor, moving the mouse pointer over a class displays the Javadoc information related to that class.
In the Java editor, moving the mouse pointer over a method displays the Javadoc information related to that method.
other extensions