My application code receives the JNDI name to look up at runtime. Hence, the JNDI name may not be configured beforehand in web.xml or in the #Resource annotation. How may I lookup an Object in such a scenario? Application is running on Tomcat 7.
You can't use resource injection but have to use programmatic lookup
new InitialContext().lookup(dynamicName)
Related
I have an ear which has ejb.jar, core.jar.
core.jar use lookup to find the bean at run time. Now the jndi path is mysystem-server-component-ear-0.0.1-SNAPSHOT/MyServiceBean/local which means <earname>/<beanname>/<localinterface>
I want to define JNDI like MyServiceBean/local. Where my MyServiceBean is the ejb bean and it use local interface.
I use EJB 3.1 without ejb-jar.xml and jboss.xml. All the wiring done through annotation.
How can I define my own JNDI name which I can lookup
Did you try #EJB(mappedName = "yourJndiName")?
If your JNDI lookups are not working as expected, then you should always check your JNDI tree from within the administration frontend (should be somewhere in jmx-console/JBoss/service=JNDIView or similar). Sometimes the name of the remote interface, etc. is added to your JNDI name by your application server.
We have a multimodule Java EE 5 project running on Weblogic 10.3.x. One module has the EJBs and our batch processor is running from the web-module. Since we don't have CDI in JavaEE5, we have to do a JNDI-lookup on the EJBs. The EJBs are defined with #Stateless on the class and #Remote on the interface.
I have succeeded accessing the EJBs by looking the following string:
ejb/batchService#com.example.service.batch.ejb.BatchServiceRemote
However, I belive this is highly platformdependent, and I suspect I should have put something inside the web.xml and probably into the weblogic.xml at least in the web-module - maybe even in the EJB module...
Could anyone enlighten me how to do this propperly? Or is this the best way available?
JNDI format of local bean is
java:comp/env/BeanClassName
JNDI format for remote bean is
mappedName#com.package.BeanClassName
for
#Stateless(mappedName = "mappedName")
public class BeanClassName {
PS. This format supported by WebLogic 10.3. Behaviour of another application servers may be differentю
Prior to EJB 3.1 / EE 6, there are no standardized lookup strings for EJBs. Since they're not standardized, hard-coding the actual binding name of the EJB does make your project product-specific.
The best solution is to create another level of indirection: declare an <ejb-local-ref> in web.xml (or as #EJB/#EJBs on a servlet or other component class), and then use java:comp/env/xyz to lookup the ref. Then, use platform-specific bindings for the EJB ref.
JNDI is a mean to retrieve/store data or objects from string names. This feature is provided by the container running the application.
ApplicationContext allows the creation and retrieval of beans from their string name.
Both serve similar needs. Yet, Spring offers means to retrieve objects from JNDI. One can also access JNDI via the JndiTemplate.
Is there a real need to use JNDI in Spring? Which problem does it solve that ApplicationContext does not?
The Application Context would not help you in looking up a REMOTE object. It will only look for objects in the current application, which are not remote.
See the following "Context.PROVIDER_URL". You can get access to REMOTE objects like EJBs or RMI or JMS, etc. Also, you could access any resource managed by the Java EE Container such as a DataSource.
ht.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
ht.put(Context.PROVIDER_URL,"t3://HOSTNAME:PORT");
It's a question of scope. Spring's scope is limited to your application inside its container. JNDI is a global naming API that can plug into many different naming/directory architectures.
I want to write an application which has 2 EJBs. This application can run in both OpenEJB and WebLogic 10.3. Both of the EJB are EJB 3.0.
I know how to implement in both OpenEJB and WebLogic, but the problem is I want to use the same code to deploy to both environments. I think the problem is that how to do JNDI lookup, because WebLogic's Context.INITIAL_CONTEXT_FACTORY is weblogic.jndi.WLInitialContextFactory but OpenEJB is not.
Current idea is the 1st EJB use a service locator to lookup the 2nd EJB and the service locator will read different INI in 2 environments. Is there any other suggestion? Is there a solution I can just use annotation, no need to use external INI files.
The 2 EJBs live in one container, but it's possible one will be move to other container in the future.
Update on 2011/10/06
By David's suggestion, I put some change. The code is a POJO, not JUnit code. It doesn't use #LocalClient and initialContext.bind("inject", this); (I put the 2 code in my JUnit code)
Put resources\META-INF\application-client.xml (only contain )
Put resources\jndi.properties
jdbc/OrderDB = new://Resource?type=DataSource
jdbc/OrderDB.JdbcDriver = oracle.jdbc.OracleDriver
jdbc/OrderDB.JdbcUrl = jdbc:oracle:thin:#*.*.*.*:1521:test
jdbc/OrderDB.JtaManaged = false
jdbc/OrderDB.UserName = test
jdbc/OrderDB.Password = test
Lookup code
InitialContext ctx= new InitialContext();
ctx.lookup("jdbc/" + name);
The following is the log, OpenEJB creates the JNDI for the database. I also use Eclipse debug mode to see the content of "ctx" and find "jdbc/OrderDB" in MyProps
INFO - Configuring Service(id=jdbc/OrderDB, type=Resource, provider-id=Default JDBC Database)
But finally I still cannot lookup it. I also try to use ctx.lookup(name), ctx.lookup("java:comp/env/jdbc/" + name) and the result is the same.
javax.naming.NameNotFoundException: Name "jdbc/OrderDB" not found.
Update on 2011/10/12
Base on David's comment, before Java EE6, I think the only solution is to use a service locator and some configuration to use different JNDI between WebLogic and OpenEJB. The following is the test result.
DB: WebLogic: OrderDB, OpenEJB: openejb:Resource/jdbc/OrderDB
Transaction manager: WebLogic: javax.transaction.TransactionManager, OpenEJB: java:comp/TransactionManager
EJB: Both of them just lookup the EJB name without any prefix
The question in the update is a very different question, so posting a different answer.
No Global JNDI prior to Java EE 6
The long and short of it is that prior to Java EE 6, there is no global JNDI. So it is quite literally the case that the question "what is the JNDI name of x" is an unanswerable question. Each EJB has its own private JNDI namespace and "POJOs" don't have any namespace at all, they use the JNDI namespace of whatever EJB invoked it. So to make "java:comp/env/myDataSource" appear as global as possible, you have to declare that reference for every single EJB in the application.
The amount of configuration work this creates for users is quite devastating. In Java EE 6 there is finally Global JNDI and three new standard namespaces, java:module, java:app and java:global. Any Global JNDI functionality existing prior to Java EE 6 is vendor-specific and non-portable.
The vendor-specific and non-portable way to do a Global JNDI lookup in OpenEJB for the given name would be to lookup openejb:Resource/jdbc/OrderDB
Calling a spade a spade
In OpenEJB we deliberately do not support non-standard lookups like jdbc/OrderDB or java:jdbc/OrderDB as some vendors do. The required prefix for global names in OpenEJB is openejb:.
JNDI is complex and confusing enough and making non-portable names look like portable names doesn't do users any favors. If a certain style of naming is not portable and going to create vendor lock-in, it should look like it. So with the openejb: prefix, you can access anything you need globally but it is at least clear that what you are doing is not portable and should not be expected to work in other platforms without some modification.
Note that there is a standard jndi.properties file you can use to externalize 100% of the config normally passed in as properties to the IntitialContext
You can still use a service locator pattern as it can make your code look a little nicer and perhaps easier to maintain, but the actual server connection information can be easily externalized.
You just need to make sure the jndi.properties file is on the client's classpath at the root (i.e. not in a META-INF directory). The IntialContext will find it and load it. Any properties passed into the IntialContext constructor will simply override those passed in via jndi.properties
On the OpenEJB side it should be possible to change the JNDI name format so that it matches the WebLogic format. If not, let me know and we can add any missing meta-data to the formatter so that it is possible to match it exactly.
Can't you just use the default context? Then you don't have to specify the specific implementation and you can do the lookup via a standard reference.
Otherwise I think you are left with some sort of properties file to determine the context details at runtime.
I have been working through this tutorial. Halfway though it creates an interface and facades for an EJB. Can anyone tell me when I reference the interface using the #EJB annotation, where does it actually make the link between the interface and the actual enterprise java bean itself.
Thanks for the help.
~ Kyle.
It is AFAIK not mandated by the J2EE specification how this is actually solved or implemented by the application server. The most common solution is that the app server uses its own mapping between bean class names and JNDI names, so that depending on the bean class name, it is bound to a specific JNDI path when deploying the application and the same class name -> JNDI path conversion is used for injecting the EJB reference on the "client side".
It will be done inside the EJB container.
When you add this annotation, you'll actually be telling the IoC container of your application server which implementation of the given EJB you want.