Fibonacci sequence is sequence with subsequent number is the sum of the previous two. See snapshot below from wikipedia.
We can implement this algorithm either using recursion or without. Let see both.Before the implementation let see how is the sequence defined for every F(n).
F(0) = 1 or F(0) = 0 in some definition
F(1) = 1
F(n) = F(n-1) + F(n-2)
Now these are implementation using Java
With Recursion
int fibo(int in){
if(n <= 1){
return n
}else{
return fibo(n-1) + fibo(n-2);
}
}
Without Recursion
int fibo(int n){
if(n <= 1){
return n;
}
int fibo = 1;
int fiboPrev = 1;
for(int i = 2; i < n; ++i){
int temp = fibo;
fibo += fiboPrev;
fiboPrev = temp;
}
return fibo;
}
written by Deitel. Really complete book with enjoyable colored text that good enough against boring in reading. The books consist all of fundamental material to mid advance material such as basic of thread, GUI and servlet. Enormous code sample is spread around the book that can be tried for learning and doing approach. The next book is 
that is consisted advance material continuing the former book.
by Jacquie Barker from Apress and 
written by Mike O’Dochery from Wiley. Barker book explain Java from software development point of view. In that book, reader is guided to build real Java software step by step. O’Docherty more focus in Object-Oriented approach mainly discuss about UML although it is really intended for reader who want develop Java application. Same as Barker, O’Docherty book also consist real software development as example.
by Rich Rapossa from Willey) I found that JVM is written by C++. After all of advantage is offered by Java it still have to admit superiority of old complex difficult of C++. Yeah when reach the necessity of speed and hardware accessing such as needed by JVM, C++ is always needed.