This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
That depends on where Eclipse is configured to put it. Normally there is a classes or bin folder in the project directory which contains the class file. If you still can't find it, go to the Eclipse package explorer window and right click on the project icon. From the menu select 'Build Path' then 'Configure Build Path'. In the dialog that opens select the 'Source' tab and look at the field at the bottom of the window labeled 'Default Output Folder'. This is where the class files are put.