JavaRanch EJB and Other J2EE Technologies

Measure size of JMS object message

Fri, 9 May 2008 13:04:59 MDT

Hi

Is there any way to measure the size of each JMS object message in application servers such as Jboss?

Thanks

EJB QL - Changes with data in Table NOT REFLECTED

Thu, 8 May 2008 23:36:57 MDT

Here is my scenario -

I have an Entity Bean (MyTable) -

code:

@Entity
@NamedQueries({ 
 @NamedQuery(name = "MyTable.findAll", 
 query = "select m from MyTable m"),
 ..........
 ..........
 public class MyTable implements Serializable {
 private String name;
 private Long roll_no;
 ..........
 ..........
 public String getName() {
 return name;
 }
 
 public void setName(String name) {
 this.name = name;
 }
 ..........
 ..........

I Have a Session Bean (MySession) ...

jboss and ejb2

Wed, 7 May 2008 15:42:53 MDT
I have a servlet which calls an ejb (2.0). When I go to run the
app, I get the following error:

java.lang.ClassCastException
com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:229)
javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
fibo.servlets.FiboServlet.lookupFibonacciBean(FiboServlet.java:78)
fibo.servlets.FiboServlet.doPost(FiboServlet.java:46)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

Here's the code I use to lookup my ejb:

private Fibonacci ...

JMS Application Vs Non-Java Application

Wed, 7 May 2008 08:54:52 MDT
Hi All,

I'm new to JMS. i've basic query whether can i communicate a Non-Java application(.Net ,C, C++) by using an Application in JMS.

And also suggest me good tutorials and API's.

Any suggestions would be appreciated.Thanks in Advance

EJB3: when should session beans be used?

Wed, 7 May 2008 08:16:52 MDT
As they are not POJO and can only run in an application server, why should I
choose EJB3 session beans over other technologies that use POJO?

does GlassFish v2 support only EJB3.0 or also EJB2.x

Wed, 7 May 2008 03:36:52 MDT
i want to install glassfish v2 but i have old EJB2.0 beans i want to deploy..does EJB2.0 supported in glassfish V2?

EJB3: standalone session bean?

Tue, 6 May 2008 20:24:51 MDT
Is it possible? If not, where can I download a free EJB3 application server?

problem in deploying the EJB into the WebSphere app server

Tue, 6 May 2008 02:42:48 MDT
Hi Everyone,

I am very new to this EJB. I have developed a simple EJB application and deployed it into the WebSphere app server. It has shown the message like "Successfully deployed". I am using the MyEclipse Blue. After starting the server, in the logs I am getting a message like

"naming exception caused the creation of the home obj to fail"

Can anybody please tell me what is the problem and why I am getting this message?

Thaks,
Gayathri

JNDI example using LDAP

Mon, 5 May 2008 22:06:48 MDT
Could any one help me to run a LDAP example. I am going through sun tutorials for JNDI, http://java.sun.com/products/jndi/tutorial/getStarted/examples/directory.html (http://java.sun.com/products/jndi/tutorial/getStarted/examples/directory.html)

but not getting correctly that how to configure

ldap://localhost:389/o=JNDITutorial

Could you please provide me a good link to understand JNDI.

JMS - ActiveMQ works, Oracle AQ JMS does not

Mon, 5 May 2008 11:52:47 MDT
We're prototyping open source replacements for a legacy application.

When we're running a prototype again ActiveMQ, we don't have any problems. Well, we ended up running spring on the applet side(!) because of an initialization issue with the naked activemq client libraries, but that was a mere annoyance.

When we're running a prototype against the Oracle JMS wrapper on ActiveQueues, we run into a brick wall. (The legacy app uses AQ, we're prototyping on new AQ queues with JMS support enabled.) With the help of some online resources we've been able to get a test case to the point where the JMS calls throw a generic "corrupt data" exception, and the corresponding AQ-specific calls throw a NPE when writing to a HashT...

Minimizing EAR Redeployment

Mon, 5 May 2008 10:00:46 MDT
I have an EAR file containing a generic module which acts as a generic MDB as well as a number of JARs representing our services which is invoked by the MDB. The problem that is occurring is that whenever we change a module, we have to redeploy the whole application. I was wondering if there is a way to separate our JARs from the EAR file so that we can plug it into the server's deploy directory whenever a change is made. Can anyone help me out here?

Thanks in advance,

Juan

NoClassDefFoundError in Cluster with JNDI

Mon, 5 May 2008 07:40:46 MDT
All,

Thanks for reading my post.

I have a curious problem. I have a cluster in weblogic that contains two (hopefully) identical servers. I deploy my webapp to both. A proxy sits "out in front" of the weblogic cluster.

The problem occurs when I enable both servers for failover. If the "L" server is the one to service the user request, everything works fine. If the "M" server is the one to service the request, it seems to fail in getting the JNDI root and gives the NoClassDefFoundError on my EJB that services the request.

To get things to work correctly, I need to shutdown the "M" server and just have the "L" server active. Ultimately, this is not a solution.

The JNDI tree for...

reg: EJB stateful session bean

Mon, 5 May 2008 05:02:46 MDT
Hello friends,

when i am reading EJB stateful session bean, came little bit confuse about how a statefull session bean will track that session bean belongs to a specific Clint.... As i think it may be using "" session using url rewriting technique ( session.encodeURL() ) .. just want to know how come it be correct.. if not can any one please tell me about this how it will track ......

Thanks & Regards

MDB Listening to Multiple Queues

Sun, 4 May 2008 22:30:36 MDT
I have a single MDB and i want it to listen to more than one queues say q1 and q2 I need to know what changes do i need to make in deployment descriptor to accomplish the same
Kindly note that i am using Weblogic 8.1 SP 4
would appreciate your early responses on this..

Thanks
Hemanth

Help me with Ejb3!

Sun, 4 May 2008 21:56:36 MDT
I'm a beginner at EJB.
I use Myeclipse 6.0, JBoss 5.0.0.Beta2 to deploy a stateless session bean - it's successful.
But I can't write app client to access these bean.
How can I do? - what're .jar files to use? or how can write .xml file?
Please help me, thanks!

Transactions in a J2EE environment

Sun, 4 May 2008 16:02:35 MDT
Folks,
I had a question regarding handling transactions in a J2EE environment.Lets say that I have three tables to be updated-Employee,Department and Emp-Dep.How do I implement the transaction logic for this-ensuring that department table gets updated only when the Employee table gets updated successfully.Else the entire transaction needs to be rolled back.Please advise.

Thanks
Dominic

servlet extension

Sat, 3 May 2008 14:40:32 MDT
how do i know my istalled sdk have servlet extesion or wether i have installed j2ee platform?
in my controlpanel it shows me that i have installed J2SE development kit 5.0 update 15.

Thank you

Mbean state query

Fri, 2 May 2008 00:52:27 MDT
Hi,
Are Mbeans always stateless or is it also possible to keep the context of a session?How can this be done?

Thanks,
Jack

NameNotFoundException

Thu, 1 May 2008 23:22:27 MDT
Hi everyone,
Im an ejb3.0 newbie and am trying to run my first bean, however i keep getting a NameNotFound exception everytime i run the client code, I'm using Jboss and have added all jar files required for the application to run.
One thing that seemed odd when i deployed the bean was that no reference was made to JNDI name by exception at the server end which is usually made as soon as the bean is deployed, could someone please tell me where im going wrong.

Thanks in advance,
Ravissant Markenday

EJB transaction issue

Thu, 1 May 2008 19:10:26 MDT
I am having an issue with EJB transactions (regradless of BMT or CMT).
If i have a say a bean which has the following methods

interface_meth1() - (method in remore interface) - Transaction attribute is 'Not Supports'.
{
get db connection (say conn) from connection pool //step 1
Call interface_meth2(conn) //step 2 (passing the db connection is step 1
(Please note that i do a local look up of the same bean for invoking interface_meth2)
}

interface_meth2(Connection conn) - Transaction attribute is Required (methd in local interface)
{
insert //step 3
update //step 4
insert //step 5
}

If step 5 throws an exception, i see changes made by st...

EJB LookUp Version Problem

Thu, 1 May 2008 12:52:25 MDT
I have a remote EJB method and deployed it on the Websphere using java version 1.5 and am trying to look it up using a standard standalone client which runs on java version 1.4 which prints the following exception in the log:
The java class could not be loaded. java.lang.UnsupportedClassVersionError
Works fine when i look it up using java version 1.5
If some one can help me out on this problem.
Thanks in Advance

EJB Transactions issue

Thu, 1 May 2008 12:46:25 MDT
I am having an issue with EJB transactions (regradless of BMT or CMT).
If i have a say a bean which has the following methods

interface_meth1() - (method in remore interface) - Transaction attribute is 'Not Supports'.
{
get db connection (say conn) from connection pool //step 1
Call interface_meth2(conn) //step 2 (passing the db connection is step 1
(Please note that i do a local look up of the same bean for invoking interface_meth2)
}

interface_meth2(Connection conn) - Transaction attribute is Required (methd in local interface)
{
insert //step 3
update //step 4
insert //step 5
}

If step 5 throws an exception, i see changes made by step 4 commited i...

this is my first ejb

Wed, 30 Apr 2008 02:30:21 MDT
hi,
this is my first ejb test ,i met a question that happy a exception

chinese boy

choosing between entity and session bean

Tue, 29 Apr 2008 05:58:18 MDT
good day,

1.what basis should i choose between session and entity bean on?
2.if i have to put them together, what is the most important role each should perform?

have a nice day,
krishna prasad g

Transaction problem

Mon, 28 Apr 2008 06:32:15 MDT
Could any please help me with the following exception??

javax.jms.JMSException: Could not create a session: javax.resource.ResourceException: Transaction is not active: tx
=TransactionImpl:XidImpl[FormatId=257, GlobalId=awsdev201/118096, BranchQual=, localId= at org.jboss.resource.adapter.jms.JmsSessionFactoryImpl.allocateConnection(JmsSessionFactoryImpl.java:403) at org.jboss.resource.adapter.jms.JmsSessionFactoryImpl.createSession(JmsSessionFactoryImpl.java:369) at com.alcatel.util.jms.JmsUtil.sendRequestsOnDestination(JmsUtil.java:144)
at com.alcatel.ni.datacollection.collection.DataCollectionBean.onMessage(DataCollectionBean.java:96) at sun.reflect.GeneratedMethodAccessor598.invoke(Unknown Source) <...

where I am going to put the client code ?

Mon, 28 Apr 2008 05:04:15 MDT
I am going to make a project using struts as web-tier and EJB as a business tier . Now prolem is the bridge between these two tiers . where I will put the client code for ejb ??

I am using Jboss .

deployment layer

Mon, 28 Apr 2008 03:38:15 MDT
What does Deployment Layer mean?. Is it needful for all J2EE application (all type of architecture).I cant develop J2EE application without Deployment layer. From a book, I found description, as "It is wrapper class used to publish the Business layer's object functionality to Java classes". I make me to assume that "Deployment layer only useful for distributed architecture".

error on running an ejb application

Mon, 28 Apr 2008 03:08:15 MDT
Hi,

I am facing the following error , while trying to call an ejb via a client.:-
code:
[java] javax.naming.NameNotFoundException: interest not bound.

I am testing a tutorial from the link :- http://www.huihoo.org/jboss/online_manual/2.4/ch01s15.html (http://www.huihoo.org/jboss/online_manual/2.4/ch01s15.html)
The line throwing exception is :-
code:
Object ref = jndiContext.lookup("interest/Interest");

Any help on this?

EJB Beginner Book

Mon, 28 Apr 2008 00:44:14 MDT
HI all,

Please let me know which book is good for beginner of EJB 3.0.

Regards,
Indravadan Patel

Trigger for MDB

Sun, 27 Apr 2008 22:18:14 MDT
Hello All,

How could i use Oracle trigger to write a message to a queue and have a JMS provider in JBOSS.

Thanks in advance

J2EE Web Hosting

Sun, 27 Apr 2008 03:08:11 MDT
Hello All,
Does any one know a good J2EE Web Hosting out there? I am trying to get one so that I can host my site developed in Servelts and JSP.
thanks.

How to create Database connection using Datasource Mechanism approach

Sat, 26 Apr 2008 05:46:08 MDT
Hi Friends,
I want to know how to create the database connection using Datasource interface mechanism..

I want to know about the JNDI Lookup Mechanism, Connection pooling & singleton approach used in this mechanism to establish the connection..

It would be helpful if you can provide any example pls ..

Many thanks in advance !

Regards,
Somesh

Problem with persisting entities because they become detached

Fri, 25 Apr 2008 14:26:06 MDT
Hi,

I'm working on a web application where I'm currently not able to persist certain entities because I get this exception:

"org.hibernate.PersistentObjectException: detached entity passed to persist: Entities.Person"

For a more complete understanding of the problem I will show you the most relevant code from my entities (They're related to each other in several steps so to see the connections I'm showing you 4 entities):

code:
@Entity
@Table(name = "cv")
public class Cv implements Serializable {

@Id
@GeneratedValue (strategy = GenerationType.IDENTITY)
@Column(name = "cvId", nullable = false)
private Long cvId;

@JoinColumn(na...

Two transactions in one CMP MDB

Fri, 25 Apr 2008 10:22:06 MDT
I have a CMP MDB, triggered by websphere scheduler and do some process. There is a requirement that I need to write a record in the error logging table when exception thrown from the process. But if there is exception, my transaction is rollback and so as the record in the error logging table. Is there any way I can begin another transaction in CMP?

I'm using websphere 6.1 and oracle 10g.

Thanks in advance.

Rick

Webapp and LDAP authentication

Thu, 24 Apr 2008 03:54:02 MDT
Hi,

I'm trying to authenticate user and password in a form of my web application on LDAP server.

For do this, I wrote:

Hashtable<String,String> env = new Hashtable<String,String>(4);
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
env.put(Context.PROVIDER_URL, "ldap://......:389/DC=.....,DC=....");
env.put(Context.SECURITY_PRINCIPAL, userid);// User
env.put(Context.SECURITY_CREDENTIALS, password);// Password

try {
new InitialDirContext(env);
log.info("User " + userid + " authenticated in LDAP mode");
} catch (AuthenticationExce...

How to communicate with 2 different ejb modules residing in different appplications

Wed, 23 Apr 2008 21:14:01 MDT
Hi All

I have a question on how to call amethod from a ejb class in different application to the one residing in a different application. Is it possible?
What all would I need to do so.

e.g.
I have an ejb class in myappejb.jar which is part of my application myapp.
I need to call a method in another ejb which resides in pyapp2ejb.jar part of different application called myapp2. These applications will be residing on the same application server.

Need help on this

BMT Rollback Issue

Wed, 23 Apr 2008 14:26:00 MDT
Hi

I have a BMT (SLSB) wherein the code looks like:

//Get utx from session context (I have also tried getting it from a Context lookup)
try
{
utx.begin();
<dml st1>
<dml st2>
utx.commit();
utx.begin();
<dml st3>
<dml st4>
utx.commit();
}
catch(....)
{
utx.rollback();
}

st4 raises an exception which gets trapped but the changes by st3 is not getting rolled back. I am using Weblogic 9.2.

I tried getting a hook onto the transaction using weblogic.transaction.Transaction and printing the transaction object. The transaction object is unique after a begin and c...

Why does Stateless Session Beans need pooling?

Wed, 23 Apr 2008 14:00:00 MDT
Hi, I wanna know if somebody has some explanation about why does SLSBs need pooling. What are it's benefits? Couldn't it be one instance per JVM? Since you don't need to keep any conversational state... Isn't it useless having many instances of the same class on server's memory?

JMS message selector

Wed, 23 Apr 2008 10:14:00 MDT
My application has JMS selector similiar to one mentioned below:
NumberOfOrders = 1

I understand that a message will be picked up by the JMS client, if property value of "NumberOfOrders" in JMS message is set to 1.
But, i am not sure what will happen if "NumberOfOrders" property is not added to the JMS message.
Probably, selector condition will resolve to "null > 1" in above case and message will not be picked up by JMS client.
Has someone tested this before?

Getting 2 phase commit exception with SQL server and DB2 datasources....

Wed, 23 Apr 2008 01:47:59 MDT
Hi, I am using 2 datasources. one for SQL server(XA datasource)and another for DB2(not an XA).

In the particular transaction, our code gets nearly 3 connections using getConnection of XA datasource and 2 connections using DB2 datasource. Getting the following exception when the transaction is about to commit: "An illegal attempt to commit a one phase capable resource with existing two phase capable resources has occurred." Is it required to close all connections before committing?

Could you pls help me out of this problem soon??? Thanks in advance.

why java:comp/env

Tue, 22 Apr 2008 22:21:47 MDT
Hi,
I have tried to underdstand by googling why we need to prefix "java:comp/env" with JNDI name every time we lookup,but still i am not very sure about this.
Can someone please explain this in simple terms so that a new guy in the JAVA world can understand.

thanks,
Ajse

Problem with using Jboss

Tue, 22 Apr 2008 12:13:46 MDT
Hi,

I am using my Jboss Application Serer (Version: 4.2.2.GA) to run my JMS application. As long as I am using "jnp://localhost:1099", it works, but when I change localhost to the IP address ("jnp://132.205.93.311:1099") of the same machine, it gives me the following error. I also changed the jndi.properties like this:

Code:
code:

Hashtable props = new Hashtable();

props.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
props.put(Context.PROVIDER_URL, "jnp://132.205.93.311:1099");
props.put(Context.URL_PKG_PREFIXES, "org.jboss.naming rg.jnp.interfaces");

Error :

Can't invoke a method on an -existing- bean (JEE)

Tue, 22 Apr 2008 07:27:45 MDT
Hi,

I'm learning JEE and tried a basic example with an entity bean Person
and a stateless bean PersonFeederBean that is getting a list of persons and to persist them, print them and maybe remove them.

The PersonFeederBean is called by ClientPersonFeeder creating the list of person to store.

The code compiles in eclipse 3.2 with java compliance level 5, the jar can is deployed (on JBoss 404), the PersonFeederBean can be looked up and narrowed; to make sure it is not empty I added a test retrieving the methods; they are there.

But when I want to call one of these methods I get the error:

"$Proxy0.testInstanceAlive(Unknown Source)" as listed at the end of the code section.

EJB3.0 transactions

Mon, 21 Apr 2008 10:28:18 MDT
Hi,

I understand all the EJB3.0 transaction attributes such as required, requires new etc..

I have a small question, what does it mean when I see statements such as "If the caling method (the method calling the EJB method) is already running in a transaction". Does it mean if for example a servlet is calling the EJB in a transaction controled by JTA such as:

transaction.begin();
do some logic;
call the ejb method;
transaction.commit();

Thanks

Mark

need some j2ee pro advice

Sun, 20 Apr 2008 16:00:14 MDT
I have some j2ee experience but not very mcuh. I know java, jsp, servlet, struts, hibernate. But I haven't done anything like Spring, EJB 3, Ajax, web service stuff. Can you recommend me some books that provide step by step hand on instruction for these subjects ? I don't like those pure theory book. I like the books that provide real and small examples so that you can not only learn the theory but also gain some hands on experience.

Thanks for your sharing !

Problem with JMX

Sun, 20 Apr 2008 09:06:33 MDT
Hello Everybody,
I have written a very simple jmx program. The code is as under.

HelloMBean
code:

public interface HelloMBean {

public void setMessage(String message);

public String getMessage();

public void sayHello();

}

Hello
code:

public class Hello implements HelloMBean{

private String message = null;

public Hello(){
message = "Hello there";
}

public Hello(String message){
this.message = message;
}

public String getMessage() {
// TODO Auto-generated method stub
return message;
}

Calling deployed EJB

Sun, 20 Apr 2008 01:10:26 MDT
I am trying to deploy my first EJB, it is the same example given in [URL=Book (http://www.amazon.com/Mastering-Enterprise-JavaBeans-Patel-Sriganesh/dp/0471785415)]Mastering EJB 3.0[/url]. As described in the book I have create a business interface and wrote an bean implementation of it. Since it is EJB3.0 I have used annotation and no deployment descriptor file. Deployed the same in JBOSS using NetBeans.
Now I wrote the client to call a method (sayHello) in the bean class and the code goes like this (I tried using the same told in the example but it didn't workout

code:
Properties properties = new Properties();
properties.put("java.naming.factory.initial", "org.jnp.interfaces.NamingContext...

Design patterns

Sat, 19 Apr 2008 04:44:23 MDT
Hello friens,

Please wxplain this in brief.

Presently we are developing a classified by using Struts that has components like Eventcalender,Housing, Jobs, sale etc .And My Module is Housing.
Housing has internel components like House for sale, house for rent etc

Can any one explain What are the desine patterns i need to use for this.

And How many DAO's i need to use.
Thanks,
Krishna Tota

DAO for module

Sat, 19 Apr 2008 04:34:23 MDT
Hello friens,

Please wxplain this in brief.

How many DAO's will be there for a single module in general?
Please explain dy taking a small module.

Thanks,
Krishna Tota

Help on DAO

Sat, 19 Apr 2008 04:30:23 MDT
Hello friens,

Please wxplain this in brief.

How will transaction start and transaction end?

Which object will be responsible for starting and ending a transaction?
Please explain with example.

Thanks,
Krishna Tota