This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Because arrays don't override the "equals" method. Interestingly enough, someone just raised this very question over in the Java in General (Advanced) forum; see that thread for a more detailed answer.
There's a family of overloaded two-argument static methods named java.util.Arrays.equals() which you can use to compare arrays elementwise.