ending different in movie than from book?

Yep. In the book, Josie and Jacob broke up at the end of the novel, with a reconciliation not really in sight. In the movie, they are still together. That's about the major difference in terms of the ending, but there are a lot of differences between the screenplay and the novel, such as John's suicide note, type of suicide, the merger of Carly/Ivy and the disappearance of Lee, the fourth friend of Sera, Anna and Josie.