Weld not initializing properly

Question

I am setting up basic environment for learning CDI in JavaEE7. I have the following code for starting Weld. Just a startup and shutdown.

package         


        

Answer 1

To set up a learning CDI environment, all you need is a CDI implementation such as the Weld reference implementation; you don't need a Java EE container.

The easy way is to create a maven project with a dependency in pom.xml: (Make sure to create an empty or the minimal beans.xml file in META-INF directory before you run the java application. If you go for maven, you can create META-INF in the src/main/resources directory)

    org.jboss.weld.se
    weld-se
    2.3.4.Final

Here's the application:

public class CdiApplication {
    private Weld weld;
    private WeldContainer container;
    private BookService bookService;

    private void init() {
        weld = new Weld();
        container = weld.initialize();
        BookService = container.instance().select(BookService.class).get();
    }

    private void start() {
        Book book = bookService.createBook("My title", "My description", 23.95);
        System.out.println(book);
    }

    private void shutdown() {
        weld.shutdown();
    }

    public static void main(String[] args) {
        CdiApplication application = new CdiApplication();
        application.init();
        application.start();
        application.shutdown();
    }

}

The Book class:

public class Book {   // Book is a POJO
    private String title;
    private String description;
    private double price;
    private String id;    // ISBN or ISSN
    private Date instanciationDate;

    public Book() {   // default constructor

    }

    public Book(String title, String description, double price) {
        this.title = title;
        this.description = description;
        this.price = price;
        // the BookService is responsible to set the id (ISBN) and date fields.
    }

    // setters and getters
    // toString method
}

And the BookService class to create an book and set its instanciation date and id (ISBN) using the injected NumberGenerator:

public class BookService {
    @Inject
    private NumberGenerator numberGenerator;

    private Date instanciationDate;

    @PostConstruct
    private void setInstanciationDate() {
        instanciationDate = new Date();
    }

    public Book createBook(String title,
        String description, double price) {

        Book book = new Book(title, description, price);
        book.setId(numberGenerator.generateNumber());
        book.setDate(instanciationDate);

        return book;
    }

}

In a servlet environment, the servlet container will responsible to bootstrap the CDI, meaning that you have to deploy your "web application" on a Java EE container such as Tomcat or Wildfly.