I am completely new to Java 8 and unable to refactor my Java 7 code:

my java 7 code is as below:

List reviewList=new ArrayList<>();

if(!reviewList.isEmpty()  &&  !(reviewList.contains(bookReview.getBookReview().get(0)))) {
    boolean flag=false;

   for(Review review:reviewList)
    {
      if(review.getUserId().equals(bookReview.getBookReview().get(0).getUserId()))
      {
        review.setRating(bookReview.getBookReview().get(0).getRating());
        review.setReviewText(bookReview.getBookReview().get(0).getReviewText());
        review.setBookId(bookReview.getBookReview().get(0).getBookId());
        review.setUserId(bookReview.getBookReview().get(0).getUserId());
        flag=true;
        break;
      }
    }
    if(flag==false)
    {
      reviewList.add(bookReview.getBookReview().get(0));
    }
}

Can anyone please help me