This week's book giveaways are in the iOS and Features new in Java 8 forums. We're giving away four copies each of Barcodes with iOS: Bringing together the digital and physical worlds and Core Java for the Impatient and have the authors on-line! See this thread and this one for details.
your question sounds like "can anybody teach me data structures in one sentence". This is impossible. Data structures is one of the key elements in programming. Do a search for java data structures and get some material, or buy a book.