@RequestMapping(params = "method=add")
 public String add(Book book) {
   System.out.println("bookname:" + book.getName());
   System.out.println("author:" + book.getAuthor());
   bookService.add(book);
   return "success";
 }
 @RequestMapping(params = "method=update")
 public String update(Book book) {
   bookService.update(book);
   return "success";
 }