Resource Injection using Annotation - Java EE5

In web application.

 

      ㅇ Container-managed object에만 사용할 수 있다.

            - container가 생성을 관리할 수 있어야 injection을 할 수있기 때문.

            - 따라서 일반 Javabean에서는 사용할 수 없다. 그러나 JavaServer Faces에서 사용하는 bean에는 사용할 수 있다.

 

      ㅇ Resource injection은 JSP에 사용할 수 없다.

            - Resource Injection을 위한 annotaion은 deployment time에 적용되기 때문에 JSP에서는 사용할 수 없다.

 

Table 3-1 Web Components That Accept Resource Injections

Component	Interface/Class
Servlets	javax.servlet.Servlet
Servlet Filters	javax.servlet.ServletFilter
Event Listeners	javax.servlet.ServletContextListener javax.servlet.ServletContextAttributeListener javax.servlet.ServletRequestListener javax.servlet.ServletRequestAttributeListener javax.servlet.http.HttpSessionListener javax.servlet.http.HttpSessionAttributeListener
Taglib Listeners	Same as above
Taglib Tag Handlers	javax.servlet.jsp.tagext.JspTag
Managed Beans	Plain Old Java Objects

 

Declaring Resource References

 

@Resource annotation은 deployment descriptor 내의 resource-ref element와 동일하다.

 

@Resource javax.sql.DataSource catalogDS;

public getProductsByCategory() {

// get a connection and execute the query

Connection conn = catalogDS.getConnection();

..

}

 

@Resources ({
    @Resource (name="myDB" type=java.sql.DataSource),
    @Resource(name="myMQ" type=javax.jms.ConnectionFactory)
})

 

 

Declaring a Reference to a Web Service

The @WebServiceRef annotation provides a reference to a web service. The following example shows uses the @WebServiceRef annotation to declare a reference to a web service. WebServiceRef uses the wsdlLocation element to specify the URI of the deployed service’s WSDL file:

...
import javax.xml.ws.WebServiceRef;
...
public class ResponseServlet extends HTTPServlet {
@WebServiceRef(wsdlLocation=
    "http://localhost:8080/helloservice/hello?wsdl")
static HelloService service;