What conditions must be met for @Inject?

Suppose there is an interface:

public interface BookDAO { public Book getBookByID(int id); } 

Class:

 public class BookDAOImpl implements BookDAO { public Book getBookByID(int id) { .....dowork } } 

And servlet:

 import javax.inject.Inject; @WebServlet("/management") public class BookStore extends HttpServlet { @Inject private BookDAO bookDAO; protected void doGet(HttpServletRequest req, HttpServletResponse resp) { List<Book> books = new List<>(); books = bookDAO.getALLBooks(); } } 

src\META-INF\bean.xml

 <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd"> </beans> 

I NullPointerException on books = bookDAO.getALLBooks() , the method in a usual console form through new BookDAOImpl works out normally.

In Spring, @Repository and @Autowired + were used to specify where to scan, but what about @Inject ?

Thank!