Eclipse provides Java API browsing but how can one search Java API for a class name or member name?

For example how can I use eclipse to search a .jar API for 开发者_StackOverflow社区a public member containing a specific word in its name?

If it's for a Class name, the easiest way is to hit Ctrl+Shift+T to bring up the "Navigate to Type" dialog. You then get a cool filtered search dialog with every indexed type name that you can find stuff from.