foreach之后输出null
for (Book book :handler.getBookList() ) {
System.out.println(book.getId());
System.out.println(book.getName());
System.out.println(book.getAuthor());
System.out.println(book.getYear());
System.out.println(book.getPrice());
System.out.println(book.getLanguage());
System.out.println("_______finish______");
}
1
null
null
null
null
null
_______finish______
2
null
null
null
null
null
_______finish______
