Eclipse has lots and lots of hotkeys, but for daily work you need only a small subset. This are the hotkeys I consider to be the most important time savers:
* Ctrl+J — Incremental Search
* Ctrl+Shift+T — Search a type, with search on typing. You can use only the upcase letters (e.g. type “MIL” to find MouseInputListener)
* Ctrl+F6 — Switch between last used files
* F3 — Open declaration
* Ctrl+Alt+H — Open Call Hierarchy
* Ctrl+1 — Quick Fix: press while cursor is positioned at member variable, parameter, selection, warnings, errors, …
* Ctrl+Space — Context Assist: press after a ., or to use macros (for, while, sysout, …). Press in class-scope to automatically create method declarations.
* Ctrl+Shift+O — Organize Imports
* Ctrl+Shift+F — Reformat source
* Alt+Shift+T — Show Refactor Quick Menu
In case these hotkeys are not enough or you have forgotten which hotkey does what, you can always press Ctrl+Shift+L to get a nice list of all the hotkeys.