Conditional dependency injection in EJB 3

Hi friends
I want to inject a session bean if a condition is true.
what can i do it ?
Message was edited by:
Saeed_Zarinfam

Hi Saeed,
There is no such capability in Java EE 5. If at deployment time the bean class and/or its associated
ejb-jar.xml has metadata that indicates injection, injection will take place.

Similar Messages

Dependency inject a EJB 2.x bean with EJB3

Hi there
I have an old EJB3 2.x bean deployed on my server, that is registered in JNDI with the name "abc/xyz/ItemLookup_v35".
Now I wrote a EJB3 SFSB bean and I want to access the old bean using dependency injection. I tried it with the annotation
@EJB(mappedName = "abc/xyz/ItemLookup_v35")
private ItemLookupRemote itemRemote;but it wasn't working. How can I explicitly set the JNDI name of an old bean, that I want to lookup for?
Any help is appreciated!
Regards,
Stephan
Edited by: MasterRefactorer on Jun 27, 2008 7:31 AM

You can use @EJB to access 2.x Remote views, but the field type has to be the Home interface.
@EJB(mappedName = "abc/xyz/ItemLookup_v35")
private ItemLookupHome itemHome;

Dependency Injection of EJB in application client

Hello,
I did a quick search and did not find a similar posting on this. I apologize if I missed one.
I wrote a simple stateless session bean based on EJB 3.0 specification. I wrote a simple client called TestCVTApplication. I am hoping to inject this EJB. Here is how I defined my application-client.xml
<?xml version="1.0" encoding="UTF-8"?>
<application-client xmlns="http://java.sun.com/xml/ns/j2ee"
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
                                        http://java.sun.com/xml/ns/j2ee/application-client_1_4.xsd"
                    version="1.4">
    <ejb-ref>
        <ejb-ref-name>cvt.server.HelloBean</ejb-ref-name>
        <ejb-ref-type>Session</ejb-ref-type>
        <remote>cvt.server.Hello</remote>
        <injection-target>
            <injection-target-class>cvt.client.TestCVTApplication</injection-target-class>
            <injection-target-name>helloEJB</injection-target-name>
        </injection-target>
    </ejb-ref>
    <callback-handler>
        cvt.client.MyCallbackHandler
    </callback-handler>
</application-client>When I run my client, I am getting the below exception
Exception in thread "main" java.lang.InstantiationException: Injection of multiple references to the same target[class = cvt.client.TestCVTApplication, field/property = helloEJB]
Thanks for your help.
Mustafa

Injection is required to be supported in Application Client main classes. This error probably means you have defined two different dependencies that have the same target field name in the main class. Did you put an @EJB annotation in the main class in addition to adding the ejb-ref in the application-client.xml? You should just use either one or the other. Also make sure that the field in the main class has a "static" modifier.
--ken

EJB 3.0 Why Dependency Injection doesn't work?

Hello Every body,
i have a serious problem with dependency injection with EJB 3.0. I have tried so many time to get the simple sun delivered samples ejb-Applications working in NetBeans IDE, but they don't. After importing in building the projects in NetBeans, i get a NullPointerException while trying to run them. Is there any body who have experience with this? What am i making wrong?
I searched for an answer since several days in google without any success. I have not found a single satisfactory explanation. I can't explain why even the examples in the java ee tutorials don't work.
Please, can somebody help? I would very greatful.
Cheers
flips
Here is an example of application (that don't work because the injection failed):
* This is the business interface for Confirmer enterprise bean.
@Remote
public interface Confirmer {
void sendNotice(String recipient);
@Stateless
public class ConfirmerBean implements Confirmer {
private static final String mailer = "JavaMailer";
private static Logger logger = Logger.getLogger(
"confirmer.ejb.ConfirmerBean");
@Resource(name = "mail/myMailSession")
private Session session;
/** Creates a new instance of ConfirmerBean */
public ConfirmerBean() {
public void sendNotice(String recipient) {
try {
Message message = new MimeMessage(session);
message.setFrom();
message.setRecipients(
Message.RecipientType.TO,
InternetAddress.parse(recipient, false));
message.setSubject("Test Message from ConfirmerBean");
DateFormat dateFormatter = DateFormat.getDateTimeInstance(
DateFormat.LONG,
DateFormat.SHORT);
Date timeStamp = new Date();
String messageText = "Thank you for your order." + '\n'
+ "We received your order on "
+ dateFormatter.format(timeStamp) + ".";
message.setText(messageText);
message.setHeader("X-Mailer", mailer);
message.setSentDate(timeStamp);
// Send message
Transport.send(message);
logger.info("Mail sent to " + recipient + ".");
} catch (MessagingException ex) {
ex.printStackTrace();
logger.info("Error in ConfirmerBean for " + recipient);
* @author ie139813
public class ConfirmerClient {
@EJB
private static Confirmer confirmer;
/** Creates a new instance of ConfirmerClient */
public ConfirmerClient() {
* @param args the command line arguments
public static void main(String[] args) {
String recipient = null;
if (args.length == 1) {
recipient = args[0];
} else {
recipient = "[email protected]";
try {
confirmer.sendNotice(recipient);
System.out.println("Message sent to " + recipient + ".");
System.exit(0);
} catch (Exception ex) {
ex.printStackTrace();
}

Try rebooting your computer. I had something similar. I rebooted my computer and it finished the update. Good luck!

Dependency Injection Problem in EJB 3.0

Hello.
I've been trying to get an example of java dependency injection working in JBoss 4.0.5.GA. I've installed it with EJB 3.0 support.
The problem is that if I try to use the injected resource, I get a null pointer exception.
The example I'm trying is a very short and simple one. Shouldn't be hard to figure out what is going wrong. Here it goes:
[root]\src\hello\MessageServlet.java:
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.List;
import java.util.ListIterator;
import javax.naming.InitialContext;
import javax.annotation.*;
public class MessageServlet extends HttpServlet {
     @Resource (mappedName="java:/DefaultDS")
     javax.sql.DataSource ejb30DB;
     public void init () throws ServletException {
     public void service(HttpServletRequest request, HttpServletResponse response)
               throws IOException, ServletException {
          boolean injectedLookingGood = false;
          boolean notInjectedLookingGood = false;
          try {
               java.sql.Connection conn = ejb30DB.getConnection();
               conn.close();
               injectedLookingGood = true;
          } catch(Exception e) {
               e.printStackTrace();
          try {
               InitialContext ic = new InitialContext();
               javax.sql.DataSource ds = (javax.sql.DataSource)ic.lookup("java:/DefaultDS");
               java.sql.Connection conn = ds.getConnection();
               conn.close();
               notInjectedLookingGood = true;
          } catch(Exception e) {
               e.printStackTrace();
          response.setContentType("text/html");
          ServletOutputStream out = response.getOutputStream();
          out.println("<html>");
          out.println("<head><title>Hello World</title></head>");
          out.println("<body>");
          out.println("<h1>Hello World</h1>");
          out.println("<form action=\"HelloWorld\" method=\"get\">");
          out.print("Injected DataSource is looking ");
          if(injectedLookingGood) {
               out.println("good <br>");
          else {
               out.println("bad <br>");
          out.print("Not-Injected DataSource is looking ");
          if(notInjectedLookingGood) {
               out.println("good <br/>");
          else {
               out.println("bad <br/>");
          out.println("<input type=\"submit\" value=\"Test Some More\">");
          out.println("</form>");
          out.println("</body>");
          out.println("</html>");
[root]\etc\META-INF\web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
<display-name>HelloWorldWAR</display-name>
<servlet>
<display-name>HelloWorld</display-name>
<servlet-name>HelloWorldServlet</servlet-name>
<servlet-class>hello.MessageServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldServlet</servlet-name>
<url-pattern>/servlet/HelloWorld</url-pattern>
</servlet-mapping>
</web-app>
[root]\etc\META-INF\application.xml:
<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://java.sun.com/xml/ns/j2ee" version="1.4"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com /xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/application_1_4.xsd">
<display-name>HelloWorld</display-name>
<description>Application description</description>
<module>
<web>
<web-uri>web-ejb3.war</web-uri>
<context-root>HelloWorld</context-root>
</web>
</module>
</application>
[root]\build.xml:
<project name="HelloWorld" default="all" basedir=".">

<property name="proj.name" value="HelloWorld"/>
<property name="proj.version" value="1.0"/>

<property name="src.dir" value="${basedir}/src"/>
<property name="build.dir" value="${basedir}/bin"/>
<property name="lib.dir" value="${basedir}/lib"/>
<property name="build.classes.dir" value="${build.dir}/classes"/>
<property name="build.jar.dir" value="${build.dir}/jar"/>
<property name="src.etc.dir" value="${basedir}/etc"/>
<property name="meta-inf.dir" value="${src.etc.dir}/META-INF"/>

<path id="build.classpath">
<fileset dir="${lib.dir}">
<include name="**/*.jar"/>
<include name="**/*.zip"/>
</fileset>
</path>

<patternset id="meta.files">
<include name="**/*.xml" />
<include name="**/*.properties"/>
</patternset>
<target name="prepare">
<mkdir dir="${build.dir}"/>
<mkdir dir="${build.classes.dir}"/>
<mkdir dir="${build.jar.dir}"/>
</target>
<target name="compile" depends="prepare">
<javac destdir="${build.classes.dir}"
classpathref="build.classpath"
debug="on">
<src path="${src.dir}"/>
</javac>
</target>
<target name="package-web" depends="compile">
<war warfile="${build.dir}/jar/web-ejb3.war"
webxml="${meta-inf.dir}/web.xml">
<classes dir="${build.dir}/classes">
<include name="**/*Servlet.class"/>
</classes>
</war>
</target>

<target name="assemble-app">
<ear destfile="${build.jar.dir}/HelloWorld.ear" appxml="${meta-inf.dir}/application.xml">
<fileset dir="${build.dir}/jar"
includes="*.war"/>
</ear>
</target>
<target name="clean">
<delete dir="${build.dir}" />
</target>
<target name="all">
<antcall target="clean" />
<antcall target="package-web" />
<antcall target="assemble-app" />
</target>
</project>
Any help would be apreciated.
Thanks in advance,
Hugo Oliveira
[email protected]

Hello Ken.
I gess dependency injection is unnavailable in servlets as of this moment. I conducted another test using a session bean that injects and tests the DataSource and a servlet calling the session bean via a refference obtained from InitialContext. It worked OK.
Here's the code:
[root]/src/hello/MessageHandler.java:
package hello;
public interface MessageHandler {
     public boolean testInjection();
[root]/src/hello/MessageHandlerBean.java:
package hello;
import javax.ejb.Stateless;
import javax.persistence.*;
import java.util.List;
import javax.annotation.*;
@Stateless
public class MessageHandlerBean implements MessageHandler {
     @Resource (mappedName="java:/DefaultDS")
     private javax.sql.DataSource ds;
     public boolean testInjection() {
          try {
               java.sql.Connection conn = ds.getConnection();
               conn.close();
               return true;
          } catch(Exception e) {
               e.printStackTrace();
          return false;
[root]/src/hello/MessageServlet.java:
package hello;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.List;
import java.util.ListIterator;
import javax.naming.InitialContext;
import javax.annotation.*;
public class MessageServlet extends HttpServlet {
     public void init () throws ServletException {
     public void service(HttpServletRequest request, HttpServletResponse response)
               throws IOException, ServletException {
          boolean injectedLookingGood = false;
          try {
               InitialContext ic = new InitialContext();
               MessageHandler mh = (MessageHandler)ic.lookup("HelloWorld/MessageHandlerBean/local");
               injectedLookingGood = mh.testInjection();
          } catch(Exception e) {
               e.printStackTrace();
          response.setContentType("text/html");
          ServletOutputStream out = response.getOutputStream();
          out.println("<html>");
          out.println("<head><title>Hello World</title></head>");
          out.println("<body>");
          out.println("<h1>Hello World</h1>");
          out.println("<form action=\"HelloWorld\" method=\"get\">");
          out.print("Injected DataSource is looking ");
          if(injectedLookingGood) {
               out.println("good <br>");
          else {
               out.println("bad <br>");
          out.println("<input type=\"submit\" value=\"Test Some More\">");
          out.println("</form>");
          out.println("</body>");
          out.println("</html>");
[root]/etc/META-INF/application.xml:
<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://java.sun.com/xml/ns/j2ee" version="1.4"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com /xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/application_1_4.xsd">
<display-name>HelloWorld</display-name>
<description>Application description</description>
<module>
<ejb>HelloWorld.ejb3</ejb>
</module>
<module>
<web>
<web-uri>web-ejb3.war</web-uri>
<context-root>HelloWorld</context-root>
</web>
</module>
</application>
[root]/etc/META-INF/web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app version="2.5" 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/web-app_2_5.xsd">
<display-name>HelloWorldWAR</display-name>
<servlet>
<display-name>HelloWorld</display-name>
<servlet-name>HelloWorldServlet</servlet-name>
<servlet-class>hello.MessageServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldServlet</servlet-name>
<url-pattern>/servlet/HelloWorld</url-pattern>
</servlet-mapping>
</web-app>
[root]/build.xml:
<project name="HelloWorld" default="all" basedir=".">

<property name="proj.name" value="HelloWorld"/>
<property name="proj.version" value="1.0"/>

<property name="src.dir" value="${basedir}/src"/>
<property name="build.dir" value="${basedir}/bin"/>
<property name="lib.dir" value="${basedir}/lib"/>
<property name="build.classes.dir" value="${build.dir}/classes"/>
<property name="build.jar.dir" value="${build.dir}/jar"/>
<property name="src.etc.dir" value="${basedir}/etc"/>
<property name="meta-inf.dir" value="${src.etc.dir}/META-INF"/>

<path id="build.classpath">
<fileset dir="${lib.dir}">
<include name="**/*.jar"/>
<include name="**/*.zip"/>
</fileset>
</path>

<patternset id="meta.files">
<include name="**/*.xml" />
<include name="**/*.properties"/>
</patternset>
<target name="prepare">
<mkdir dir="${build.dir}"/>
<mkdir dir="${build.classes.dir}"/>
<mkdir dir="${build.jar.dir}"/>
</target>
<target name="compile" depends="prepare">
<javac destdir="${build.classes.dir}"
classpathref="build.classpath"
debug="on">
<src path="${src.dir}"/>
</javac>
</target>
<target name="package-ejb" depends="compile">
<jar jarfile="${build.jar.dir}/HelloWorld.ejb3">
<fileset dir="${build.classes.dir}">
<include name="**/*.class"/>
</fileset>

</jar>
</target>
<target name="package-web" depends="compile">
<war warfile="${build.dir}/jar/web-ejb3.war"
webxml="${meta-inf.dir}/web.xml">


<classes dir="${build.dir}/classes">
<include name="**/*Servlet.class"/>
</classes>
</war>
</target>

<target name="assemble-app">
<ear destfile="${build.jar.dir}/HelloWorld.ear" appxml="${meta-inf.dir}/application.xml">
<fileset dir="${build.dir}/jar"
includes="*.ejb3,*.war"/>
</ear>

</target>
<target name="clean">
<delete dir="${build.dir}" />
</target>
<target name="all">
<antcall target="clean" />
<antcall target="package-ejb" />
<antcall target="package-web" />
<antcall target="assemble-app" />
</target>
</project>
Thanks,
Hugo Oliveira
[email protected]

EJB 3.0 Dependency Injection and reentrant Calls on SFSB

Hi there
I have a SFSB (Bean A) that injects another SFSB (Bean B) with the @EJB annotation. Now Bean A does reentrant-calls on Bean B, which is ok, because it just asks for the current state.
This results in a "javax.ejb.EJBTransactionRolledbackException: Illegal attempt to make a reentrant call to a stateful session bean from home: .....; nested exception is: javax.ejb.ConcurrentAccessException: Illegal attempt to make a reentrant call to a stateful session bean: ....."
Now I added a weblogic-ejb-jar.xml with the section:
<stateful-session-descriptor>
<allow-concurrent-calls>true</allow-concurrent-calls>
</stateful-session-descriptor>to enable reentrant calls on my SFSB. Unfortunatly this leads to problems with the DI, it simply doesnt work anymore!!! The message now is " java.lang.IllegalStateException: Cannot find object BeanBInterface with java:comp/env/ejb/BeanBInterface". Obviously the DI didn't work, the local variable isn't filled anmyore.
Is this a bug of WLS 10.0 MP1 or a feature? Should I open a bug report? Any tips a welcome!
Stephan

There is currently no possiblity in Weblogic 10 server web layer to use Dependency Injection on any other component than the ones defined in web.xml s.a.:
- servlets
- listeners
- filters
See here:
http://e-docs.bea.com/wls/docs100/webapp/annotateservlet.html
A simple POJO class part of the web application (such as a Backing Bean in JSF or an Action in Struts for example) is not benefiting from DI.
Doesn't this make Weblogic 10 a NON JEE 5 compliant server?
Why was this restriction imposed?
And how is one supposed to use DI with a simple POJO class? Why this huge inconvenience?

EJB 3.0 Dependency Injection in JSF ?

Hi,
I have a question about ejb 3.0 dependency injection in a JSF WebApp:
I Build successfully a Web Module (version 2.5) an EJB Module (version 3.0) and an EAR Module (Version 5.0). The EAR App can be deployed without errors on a Bea WebLogic Server 10.1. All modules are successfully deployed.
Inside the Web Module there is a Servlet which uses dependency injection to access the session EJB form the EJB Module. This works perfect.
Next I try to use the same EJB with dependency injection from the JSF Page via a backing bean. But when I try to access my JSP Page I got a Nullpointer Exception.
It seems that the Dependency Injection in the JSP App did not work?
Can anybody give me a hint what could be wrong?
Thanks
Ralph

There is currently no possiblity in Weblogic 10 server web layer to use Dependency Injection on any other component than the ones defined in web.xml s.a.:
- servlets
- listeners
- filters
See here:
http://e-docs.bea.com/wls/docs100/webapp/annotateservlet.html
A simple POJO class part of the web application (such as a Backing Bean in JSF or an Action in Struts for example) is not benefiting from DI.
Doesn't this make Weblogic 10 a NON JEE 5 compliant server?
Why was this restriction imposed?
And how is one supposed to use DI with a simple POJO class? Why this huge inconvenience?

ADFc 11g: EJB Dependency injection

Hello everyone,
I'm using a managed bean which references a stateless session EJB 3.0:
public class MyManagedBean {
@EJB
private SessionEJB ejb;
}If the bean is managed by JSF (ie. is registered in faces-config) then the EJB is injected correctly, but if the EJB is managed by ADF (ie. is registered in adfc-config) then there is no dependency injection. Does anybody know why this is so, and if there is a clean solution to the problem?
Searching the forum, Duncan Mills recommends a bean managed with faces-config in which the EJBs are injected, and then use managed properties to inject those EJBs in the ADF-managed beans.
Re: Accessing session beans from a managed bean
Is there a better/simpler solution?
Thanks!
Juan Manuel

Thank you.
The link helped.
The one thing i did was created a remote interface for the ejb, which showed up in jndi and then used spring DI to inject a reference to the EJB from jndi.
Will using a remote interface (instead of a local interface) cause performance issues?

When to use @Resource and when to use @EJB for dependency injection

Hi,
When do you use
@Resource and when do you use @EJB for dependency injection?
Thanks

Captain obvious: Use @EJB for injection of EJBs, and @Resource for everything else.
There was a discussion about this very topic quite recently, perhaps you can find it through the search.

EJB 3.0 client side dependency injection

Hi,
I develop an EJB 3.0 based enterprise application using Sun Java System Application Server. The application includes a Swing based client to be launched via Java WebStart. The client has to access some of the EJBs. Is it possible to use dependency injection on client side (see the @EJB annotation) and if yes how do I set the properties for this?
The following snipped hopefully explains what I mean. The class FastEntry is a class of the Swing client. My question is how can I get the deviceSessionBean initialized?
public class FastEntry extends javax.swing.JFrame {
@EJB
private static DeviceSessionRemote deviceSessionBean;Kind regards,
Matthias

Hi,
For callbacks and interceptors, you can look at this page : http://today.java.net/pub/a/today/2005/08/18/ejb3.html
For sending messages, I'd recommend to use JMS (if in clientSide), or EJB3 Message beans if in server side.
Hope that helps :)

About Dependency Injection in EJB3.0

Hi,
I'm a fresh man in EJB3.0.
Except @EJB and @Resource,is there
any other anotation can be used to
Dependency Injection?

There is currently no possiblity in Weblogic 10 server web layer to use Dependency Injection on any other component than the ones defined in web.xml s.a.:
- servlets
- listeners
- filters
See here:
http://e-docs.bea.com/wls/docs100/webapp/annotateservlet.html
A simple POJO class part of the web application (such as a Backing Bean in JSF or an Action in Struts for example) is not benefiting from DI.
Doesn't this make Weblogic 10 a NON JEE 5 compliant server?
Why was this restriction imposed?
And how is one supposed to use DI with a simple POJO class? Why this huge inconvenience?

Dependency injection

I have a query in EJB 3.0 dependency injection.
here is a sample code:
public class MyServlet extends HttpServlet {
@EJB
private HelloStateless hss;
............................................hss needs to be an interface or bean class ?

user575089 wrote:
Yes, there's a reasonable case for that, avoiding the tedious JNDI lookup. JPA Entities aren't looked up from JNDIwhy ?Do you know what JNDI is? JPA entities are either retrieved from the database, or created as regular pojos before persisting them in the db. JNDI is no place for entities.
What advantage would you have over "new MyPojo()"?probably nothing . I ask you the opposite what advantage do they get here ( without new MyPojo() style ) ?
+public class MyServlet extends HttpServlet {+
+@EJB+
private HelloStateless hss;
+............................................+
+............................................+EJBs are no Pojos, so it's not at all the same thing. With @EJB you avoid the extra InitialContext creations and manual lookups with one simple annotation.

Dependency injection/annotation Error

Greetings,
Hello everybody !
This topic's about a problem I'm currently experiencing while trying to deploy a Web Application that makes a call to an EJB using Dependency injection from a Servlet. This is the Stack trace generated when I attempt to deploy my web app:
DeployerRunnable.run Error parsing annotation for class org.servlet.TestServletoracle.oc4j.admin.internal.DeployerException: Error parsing annotation for class org.servlet.TestServlet
at oracle.oc4j.admin.internal.DeployerBase.execute(DeployerBase.java:126)
at oracle.oc4j.admin.jmx.server.mbeans.deploy.OC4JDeployerRunnable.doRun(OC4JDeployerRunnable.java:52)
at oracle.oc4j.admin.jmx.server.mbeans.deploy.DeployerRunnable.run(DeployerRunnable.java:81)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
at java.lang.Thread.run(Thread.java:619)
Here's a Snippet from the Servlet that's making the call:
*public class TestServlet extends HttpServlet {*
     *@EJB(beanName="MathEjbBean")*
     private org.logic.MathEjbBeanRemote ejb;
     protected void doGet(HttpServletRequest request,
               *HttpServletResponse response) throws ServletException, IOException {*
          ejb.sum(1, 2);
Here's the EJB implementation:
*@Stateless*
*@StatelessDeployment*
*public class MathEjbBean implements MathEjbBeanRemote, MathEjbBeanLocal {*
     *@Override*
     *public int sum(int a, int b) {*
          *// TODO Auto-generated method stub*
          return a + b;
Finally, I will post the Container-specific Deployment descriptor:
<?xml version="1.0" encoding="utf-8"?>
<orion-ejb-jar xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://xmlns.oracle.com/oracleas/schema/orion-ejb-jar-10_0.xsd" deployment-version="" deployment-time="128f9bdc917" schema-major-version="10" schema-minor-version="0" >
<enterprise-beans>
<session-deployment name="MathEjbBean" tx-retry-wait="60" location="MathEjbBean" local-location="MathEJB_MathEjbBeanLocal" persistence-filename="MathEjbBean">
</session-deployment>
</enterprise-beans>
<assembly-descriptor>
<default-method-access>
<security-role-mapping name="<default-ejb-caller-role>" impliesAll="true" />
</default-method-access>
</assembly-descriptor>
</orion-ejb-jar>
Up until this moment, I still have no clue, about the reason why I can't inject my EJB in the Web-app's Servlet.
Please Help Me
It's so hard to find information about this problem on the internet.
Best Regards,
Jose.

Hello there !
I've corrected this problem by using the same name for the @Stateless annotation and the display-name tag in the ejb-jar file, for @EJB this name should match also.
Good Luck, hope this is helpful in the future.

Dependency injection and inheritance

Given:
class abstract AbstractFoo
MyObject obj;
class ConcreteFoo extends AbstractFoo
Now, I'd like to declare @EJB on "MyObject obj" but AbstractFoo is extended by other subclasses on the client end (outside the container) and so I don't want them to have any EJB3 dependencies. Is there a way for me to declare, inside ConcreteFoo, that "MyObject obj" should have @EJB associated with it?
Thanks,
Gili

Hi Janeth,
As you can see, Web Dynpro is not a standar JEE container so itu2019s not possible to use dependency injection from a Web Dynpro layer. You have to use JNDI lookups as usually.
Perhaps the following link may help you: https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/605ff5f2-e589-2910-3ead-e558376e6f3d
You can use EJB Web Dynpro models as an alternative.
Edited by: Sergi Arrufat on Jun 3, 2008 12:27 PM

Dependency injection in a Bean (MVC)

Hello,
Is it possible to use dependency injection in a bean (MVC architecture) ?
I use it in a servlet, but I failed to use it in a bean !
Thank you for your help.

depends on which JEE specification you use. JEE6 has the CDI specification which can do what you want. JEE5 can only do dependency injection in "know server resources", such as servlets, EJBs, MDBs and JSF backing beans. Note that CDI is separated from the specification and thus can be used without having a JEE6 capable server; look into "Weld" which is the reference implementation of the CDI specification.
http://www.seamframework.org/Weld
Before CDI there was the Spring framework that could do it by the way, so that is also something that is worth investigating.

Conditional dependency injection in EJB 3

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