EJB Doubt

Hi,
while running Ejb Client program following message am getting:
Exception in thread "main" java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
* java.net.SocketException: Connection reset by peer: socket write error*
how to solve this .
Thanks & Regards
Santosh

937551 wrote:
EJB 3.0 does support Remote interfaces but only for backward compatibility.
The specs deprecates "Remote" interface,rather we should have Remote business interfaces.And the difference would be?
@Remote
public interface myRemoteInterface {
}A remote interface. There is no deprecation going on, its still the same. Only the method of declaration is different.

Similar Messages

EJB Doubts/Questions - HELP

Hi All,
I am new to EJB technology and i am learning EJB without training canter. I am just going through Java EE tutorials available on www.oracle.com .
My knowledge of EJB Session bean say:
1.     Stateful Session Bean     : Maintains the client state.
2.     Stateless Session Bean     : Does not maintain the client state.
Now I am developing Shopping Cart Example using EJB, Servlet, JSP and HTML pages.
My Project contains following pages:
1.     login.html
2.     AuthenticateServlet.java
3.     User.jsp
4.     PurchaseServlet
5.     PurchaseSuccessful.jsp
6.     AuthenticateBean – Stateful Session Bean
7.     AutheticateBeanRemote – Remote Interface of Authenticate Bean
8.     PurchaseBean – StatefulSession Bean
9.     PurchaseBeanRemote -- Remote Interface of PurchaseBean
Session Bean with its remote interface is maintained in the ejb package.
Login.html contains;
1.     textbox named “txtUser”
2.     Password textbox named “txtPass”
3.     Submit Button
On submitting the credentials, it will check for the authentication in the AuthenticateServlet.
AuthenticateBean contains
public boolean authenticate(String user, String pwd)
     if(anylogic)
return true;
     else
          return false;
The above method is exposed in AuthenticateBeanRemote Interface.
2. AuthenticateServlet contains
I have done lookup of AuthenticateBeanRemote and have created abr. Below some important code of AuthenticateServlet;
String user = request.getParamter("txtUser") ;
String pwd = request.getParamter("txtPassr") ;
boolean flag = abr.authenticate(user,pwd);
if(flag)
     // then it will direct the control to User Page
else
out.println("Failure");
User.jsp page will show me the UserID and some task that the authenticated user can do.
My question: is while redirecting the page to User.jsp from AuthenticateServlet, do I need to do URLRewritting to maintain the session or do I need to create separate HTTPSession Object or does the Stateful session bean will take care of session management on its own. i.e. no need to do anything, just transfer or redirect to User.jsp page .
User.jsp has purchase catalog of which the user will select products and click on purchase. On clicking purchase, it will take us to PurchaseServlet.
My question Now in the PurchaseServlet if I have written the code to access the methods in PurchaseBean, Whether it will be a guarantee that the authernticated and currently logged in user is accessing the methods so that only that person’s purchased items are visible and no mishap will occur regarding the user integrity.
PurchaseBean only contains the method to add the amount.
My Question: if at the same time 2-3 users are logging in the application, then whether by using the statefulsession bean, user integrity is maintained. OR do I need to use some other approach.
Please help me... I know these questions are silly but that’s the way the technology can be learned.

user8687589 wrote:
Please help me... I know these questions are silly but that’s the way the technology can be learned.You are SO wrong. You learn it by:
a) reading and studying
b) really understanding not only the technology but also the theory behind the technology
c) learning how it works, why it works, when it works and when you should or shouldn't use it
A common denominator here is that you apply thought, reason and intelligence to get not only the basics but the big picture. Don't learn how to use it: UNDERSTAND it. That does not include just demanding all the answers in a forum and expect to have the answers spoon-fed to you. First read and study, then we'll talk.

Basic EJB doubts

Hi,
According to the EJB Specification,
- Entity beans are shared access to the clients. What is it mean?.
- What is Conversational State in Stateful Session Bean?.
- Where and when should i use session bean?. Where and when shouldn't i use session bean?.
- Where and when should i use Entity bean with CMP?.
- Where and when should i use Entity bean with BMP?.
Can anyone explain with example?.
Plz.
Regards,
Senthamizh

Hi,
It has taken me a year to understand the concept of ejb and still I am not sure whether I should use it or not,In fact I had read the orielly's EJB many times and read the basics again and again then I realized how well it was explained in the Orielly.So if the basics are through the orielly is best for undestanding....
- Entity beans are shared access to the clients.
nts. What is it mean?.If you see the forums definition of EJB it says ---->
The EJB platform handles things like transaction and state management, multithreading, resource pooling, and simple searches while you concentrate on writing business logic..
The resource pooling explains the shared access point......
- What is Conversational State in Stateful
eful Session Bean?.Please refer the Orielly Ejb as it would be very vast to explain.Any way in short the conservational state means the state of the object which is being stored for the particular client...If you still did not understand please get back to me.....
- Where and when should i use session bean?.
an?. Where and when shouldn't i use session bean?.
- Where and when should i use Entity bean with
with CMP?.
- Where and when should i use Entity bean with
with BMP?.Please go through the Orielly and if still you dont get I will try my best to explain......Read the book
cooly it is easy to understand if you are good at basics....
regards vickyk

EJB statefull error doubt? interesting.. help me..

Hi all
am having one statefull bean running in the server.
and also am having one ie client and in that client
just am get the bean once and put it in the request.setSession()... then just am check everytime and reuse the same bean instance from that session but in this time while trying to call a method in bean am getting exception like the following
java.rmi.NoSuchObjectException: Could not activate; failed to restore state; CausedByException is:
D:\tools\jboss-3.2.8.SP1\server\default\tmp\sessions\minibankserverStatefulEJB-f0nwafhl-5\f0nwaq5d-6.ser (The system cannot find the file specified)
org.jboss.ejb.plugins.AbstractInstanceCache.get(AbstractInstanceCache.java:134)
org.jboss.ejb.plugins.StatefulSessionInstanceInterceptor.invoke(StatefulSessionInstanceInterceptor.java:226)
org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:101)
org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:348)
org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:179)
org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:206)
org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFactoryFinderInterceptor.java:136)
org.jboss.ejb.StatefulSessionContainer.internalInvoke(StatefulSessionContainer.java:463)
org.jboss.ejb.Container.invoke(Container.java:723)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:324)
org.jboss.mx.server.ReflectedDispatcher.dispatch(ReflectedDispatcher.java:74)
so wat i supposed to do to overcome this..
plz anyone help me..
its quit urgent..
thanks in advance

The app container usually saves the session state to file when it needs to be passivated. In your case the container couldnt find the file minibankserverStatefulEJB-f0nwafhl-5\f0nwaq5d-6.ser. It is better to store the ejb handle in session rather than the ejb object itself.

EJB more doubt

madam,
I have a table say product on which I do manipulations using an entity bean called ProductBean.
This entity bean is CMP.I wanted to execute a query which is dynamic in nature for ex: it can be any one of the below
as per the users specification from the page(They may be querying the table by selecting some critereas or not)
select * from product where name like 'mango%';
select * from product where description like '%apple%';
or...
How this can be included in my existing CMP bean .What I did is just wrote one method in the session bean of the ProductBean
(I use session beans to access entity bean and entity beans access DB.So there will be 1 session bean associated with every
entity beans.).
I am a beginner and if this does'nt make any sense please tell me the right concept of DB managemnt using EJB (I mean the theoretical side)
Thanks JINOY

You would want to create an EJB Finder see
http://java.sun.com/j2ee/1.4/docs/tutorial/doc/CMP8.html#wp85482
also look at the ejbql section

Some doubts in FI-SL?

hello friends,
I have doubts in fi-sl,
there are two tables, summary table and ledger.
why we activate summary table first?
in ledger selection,why so mnay ledgers la,lb,lc like that is there.
for every single ledger means bank take example ,
shall we have to assign to every single ledger there la or lb or lc.
plz let me know the process wiht one scenarion.
srinu

Hi,
1) a) A Web Server understands and supports only HTTP protocol whereas an Application Server supports HTTP,TCP/IP and many more protocols.
b) Web server mainly deals with sending HTML for display in a Web browser, an application server provides access to business logic for use by client application programs. The application program can use this logic just as it would call a method on an object.
c) Webserver is used only for jsp and servlets and for static functionality it has limited functionality and it doesn't provide any security ,persistence and it doesn't support EJB and JMS and JAAS like other functionality
whereas Application server provide all functionalities.
In short, Applicaion Server is a super set of which Web Server is a sub set.
2) Two-tier architecture is a client/server architecture , where a request to do some task is sent to the server and the server responds by performing the task.where as a three-tier or a multi tier architecture has client, server and database. Where the client request is sent to the server and the server in turn sends the request to the database. The database sends back the information/data required to the server which inturn sends it to the client.

Some doubts in j2ee

Hii..,
Some doubts in j2ee .plz help with as
1.What are the main difference between application server and web server
2. two and three tier architecture differences
by Anand PC

Hi,
1) a) A Web Server understands and supports only HTTP protocol whereas an Application Server supports HTTP,TCP/IP and many more protocols.
b) Web server mainly deals with sending HTML for display in a Web browser, an application server provides access to business logic for use by client application programs. The application program can use this logic just as it would call a method on an object.
c) Webserver is used only for jsp and servlets and for static functionality it has limited functionality and it doesn't provide any security ,persistence and it doesn't support EJB and JMS and JAAS like other functionality
whereas Application server provide all functionalities.
In short, Applicaion Server is a super set of which Web Server is a sub set.
2) Two-tier architecture is a client/server architecture , where a request to do some task is sent to the server and the server responds by performing the task.where as a three-tier or a multi tier architecture has client, server and database. Where the client request is sent to the server and the server in turn sends the request to the database. The database sends back the information/data required to the server which inturn sends it to the client.

Relationship field in EJB 2.0

Going thru few books on EJB 2.0, I couldn't get a clear understanding on how the container identifies the fields which are involved in relationship between two entities (in CMP).
Say for example :
STUDENT Table (Entity) contains the following fields :
STUDENT_ID INT PRIMARY KEY
NAME CHAR(20)
ADDRESS_ID INT <----------------
|
ADDRESS Table : |
|
ID INT PRIMARY KEY -----
ADDRESS CHAR(30)
CITY CHAR(20)
STATE CHAR(20)
If we write CMP EJB for STUDENT entity and maintaine a 'cmr' field for ADDRESS how does the container know ADDRESS_ID is the field where it needs to populate with Address ID. The book says container will automatically take care of that !!!!
I couldn't find this information explicitly mentioned in the deployment discriptor in many of the examples.
Does the container looks at FOREIGN KEY relation of RDBMS and identify it that way ? or ?.
Can someone help me out to clear this doubt.
Thanks.

I am also learning EJB now, according to what I knew,
ADDRESS_ID INT actually stores the value of primary key for the Address Bean, and if you set the XML deployment discriptor correctly(<cmr> field), the container will manage it automatically.
We can discuss this through email: [email protected]
William.

How to call a EJB method from Session bean method

Hi all,
I'm new to J2EE programming. I have a simple doubt .
I have already created a lookup method for EJB bean in Session bean .
My question is how to call a method of an ENTITY bean (say insertRow) from SESSION bean method(Say invoke_insertRow) .
Please provide me an example code .
Thanks in advance.

InitialContext ctx = new InitialContext();
     GeneralEditor editor = (GeneralEditor) ctx
                    .lookup("GeneralEditorBean/remote");
          GeneralService service = (GeneralService) ctx
                    .lookup("GeneralServiceBean/remote");
          LanMu lm = new LanMu();
          lm.setName("shdfkhsad");
          editor.add(lm);

Problem with @OneToOne relationship in EJB 3.0

Hi,
I'm new to EJB 3.0. If i done any stupid thing please forgive me. Here is my doubt.
I would like to use one-to-one relationship between two entities like USER and ADDRESS.
I just did like this (the below code)to enable the relationship between these two entities.
@Entity
@Table(name="internalUser")
public class InternalUser implements Serializable{
.........//field entries of the User
private Address userAddress;// Field for address entity.
.......//setters and getters
@OneToOne(cascade={CascadeType.ALL})
@JoinColumn(name="id",table="user_address")
public Address getUserAddress() {
return userAddress;
public void setUserAddress(Address userAddress) {
this.userAddress = userAddress;
} and Here is the Address EntityBean
@Table(name="user_address")
@Entity
public class Address implements Serializable{
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
//setters and getters..
}Entire Ejb application is deployed success fully. But when i try to add a User entry along with address, it is not able to save the address entry, but able to save the User entry correctly. And also it is not able to build a relationship with Address table.
Here is my code which i write to save the User
InternalUser user=new InternalUser();
user.setName("Bharat");
user.setSignnum("bhak");
user.setDescription("Patel");
Address address= new Address();
address.setAreaCode("500032");
address.setState("AP");
address.setStreet("Prashanthi Nagar");
user.setUserAddress(address);
remote.saveUser(user); Here remote is SessionBeanInterface
I'm using Postgres as a database.
Please help me in this. What necessary steps need to follow in order to use @OneToOne relationship
Edited by: chanti12345 on Apr 29, 2009 12:09 AM
Edited by: chanti12345 on Apr 29, 2009 12:11 AM

hi i solved this query.
I made few changes in Both the entity classes. Here is the code for the Entites USER and ADDRESS
@Entity
@Table(name="internalUser")
public class InternalUser implements Serializable{
.......//field entries
private Address userAddress;//address entry
......//setters and getters
@OneToOne(cascade={CascadeType.ALL})
public Address getUserAddress() {
return userAddress;
public void setUserAddress(Address userAddress) {
this.userAddress = userAddress;
@Table(name="user_address")
@Entity
public class Address implements Serializable{
....//fields and setters and getters
}see the difference in the code . after making this change i'm able to save the User with relation ship with Address. No changes needed in client code.
Thanks a lot to every one.
Edited by: chanti12345 on Apr 29, 2009 2:22 AM

EJB 3.0 Core Spec (Transaction and BMT)

On Page 342 Core EJB Specs:
If the client request is associated with a transaction T1, and the instance is not associated with a transaction, the container suspends the client�s transaction association and invokes the method with an unspecified transaction context. The container resumes the client�s transaction association (T1) when the method (together with any associated interceptor methods) completes. This case can never happen for a message-driven bean or for the invocation of a web service endpoint method of a stateless session bean.
Doubt:
Message driven beans can have Transaction attribute specified as Not Supported or Required. In the case of Not Supported - the above can happen?.
Also, why is not applicable for invocation of a web service endpoint method of a stateless session bean and applicable for a stateless session bean call?
Please guide,
Shivani

Hi Shivani,
In the JMS programming model, transactions do not propagate from the message
producer to the message consumer so there is not any possibility for a transaction to propagate
into the JMS MDB's onMessage method. However, the text could actually use some qualification
since MDBs are capable of consuming other types of inbound messages through the Connector 1.5
contracts. In those cases it is possible for a transaction to propagate into the MDB.
Regarding WebServices, Java EE 5 does not require support for transaction propagation on
web service invocations. When this text was written such propagation was prohibited. That
restriction was loosened in Java EE 5 so this also needs some rewording.
--ken

JNDI Context Retrieval in EJB 3.0

I have a doubt about JNDI context retrieval in EJB 3.0. I know that when I call a bean from another bean I can use this line:
InitialContext ctx=new InitialContext();
But I'd like to know whether in a Client I am obliged to pass this parameter:
InitialContext ctx=new InitialContext(System.getProperties());
This method was the one I called when I used EJB 2.1..Now in many examples I find both these approaches...I'd like to know what differentiates one from another and which is the standard in EJB 3.0?
I read that when calling a bean from another bean I can use the first constructor with no parameters...but in clients I am obliged to give the param..why?
Thanks!

Correct me if I am wrong: the application client
container is a "static" container: you need to know
which EJB to call at develop time and you can not
change it later without recompiling.That's not quite right. First, there's nothing special about the application client
container with respect to retrieving Java EE dependencies that is not also true
of Java EE web containers and EJB containers. The programming model for
defining and accessing EE dependencies is exactly the same, independent of
whether the code is running in an Application Client, EJB container, etc.
It's true that dependencies are defined at development time, but one of the
whole reasons for the level of indirection provided by Java EE dependencies
is to allow the target of those dependencies to change without changing code.
E.g, with EJB dependencies this is done using the ejb-link attribute in ejb-ref
or ejb-local-ref. That specifies which EJB is the target of the ejb dependency
without changing the code used to retrieve the dependency.
>
JNDI was designed to be more flexible: you can
dynamically lookup EJB homes, then call a remote
method you like at runtime. Is that flexibility lost
with application client container. Is there any way
to dynamically inquiry-invoke?In the Java EE programming model, components always define what their
dependencies are so that the deployer can configure them. The idea of
doing a direct global lookup without using a Java EE dependency is
outside the scope of Java EE. It works in many implementations but the
specifics are not portable.
We have a presentation that covers some of these topics you might find
interesting. See here :
https://glassfish.dev.java.net/javaee5/ejb/compdependencies_xmlforum_nov15.pdf

Problem in developing a simple ejb app

Hi readers,
i am new to ejb technology, so have doubt in developing and deploying a simple ejb application
i am using EJB 2.0, JBOSS 4.0 , eclipse 3.2 and java 1.5
i searched in the net , got through many materials that can guide to develop one of it.
all are using higher versions of the above, i mean, using ejb 3.0 or using xdoclet etc.
i am need of material which guides me to develop and deploy the ejb application using the same versions of softwares step by step.
please help me in this

Hi readers,
i am new to ejb technology, so have doubt in developing and deploying a simple ejb application
i am using EJB 2.0, JBOSS 4.0 , eclipse 3.2 and java 1.5
i searched in the net , got through many materials that can guide to develop one of it.
all are using higher versions of the above, i mean, using ejb 3.0 or using xdoclet etc.
i am need of material which guides me to develop and deploy the ejb application using the same versions of softwares step by step.
please help me in this

Configuring Mysql database in EJB xml file for JBoss

I am using Mysql as database , How to configure JBoss to use Mysql as the database when using ejb's( session beans)
My ejb-jar.xml is as follows
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>
<ejb-jar>
     <description>no description</description>
     <display-name>LoginJAR</display-name>
     <enterprise-beans>
     <session>
     <description>no description</description>
     <display-name>loginEJB</display-name>
     <ejb-name>loginEJB</ejb-name>
     <home>com.rfp.Session.loginHome</home>
     <remote>com.rfp.Session.loginObject</remote>
     <ejb-class>com.rfp.Session.loginEJB</ejb-class>
     <session-type>Stateless</session-type>
     <transaction-type>Container</transaction-type>
     <resource-ref>
          <res-ref-name>jdbc/rfptrack</res-ref-name>
          <res-type>javax.sql.DataSource</res-type>
          <res-auth>Container</res-auth>
          <res-sharing-scope>Shareable</res-sharing-scope>
     </resource-ref>
     </session>
     </enterprise-beans>
     <assembly-descriptor>
          <container-transaction>
               <method>
               <ejb-name>loginEJB</ejb-name>
               <method-intf>Remote</method-intf>
               <method-name>*</method-name>
          </method>
          <trans-attribute>Required</trans-attribute>
     </container-transaction>
     </assembly-descriptor>
</ejb-jar>
1) My doubts are
a). there is a username and password to access the database,
I am mentioning only the database namein the xml file like-
jdbc/rfptrack. So where should the username and password be
mentioned or declared.
b). The server showed the following error when it was started.
Caused by: java.sql.SQLException: Table 'test.jms_messages' doesn't exist
11:40:11,687 ERROR [MainDeployer] could not create deployment: file:/C:/jboss-3.2.3/server/default/deploy/Jlogs.ear
Incompletely deployed packages:
[org.jboss.deployment.DeploymentInfo@6522477c { url=file:/C:/jboss-3.2.3/server/default/deploy/Jlogs.ear }
deployer: org.jboss.deployment.EARDeployer@1e940b
status: Deployment FAILED reason: Verification of Enterprise Beans failed, see above for error messages.
state: FAILED
the server is showing that table "test:" does not exist but I am using rfptrack as the database and not test. how can I configure the server for it.
PLEASE GO THROUGH THE EJB-JAR.XML FILE AND THE SERVER ERRORS GIVEN ABOVE AND GIVE SUGGESTIONS TO RECTIFY MY ERRORS.

Hi Svend,
Please share the xml file.
I am able to acheive the result by doing the above changes.
Thanks,
Dinesh.V
PS:<SendDataOnNodes>False</SendDataOnNodes
replace with case sensitive <SendDataOnNodes>false</SendDataOnNodes

How to lookup an EJB from JSP on a Remote Server in JES2005Q4

Hi,
I am having two different domain (domain1,domain2) respectvely. My ABC.ear j2eee application is deployed on domain2 and its iiop port is 33703.In domain1 i have xyz.war (web application) and it's IIOP port is 3700 .In xyz.war i am having CallEJB.jsp file.In this Jsp file i want to lookup an EJB Service called PaymentEJB(JNDI Name is ejb/PaymentEJB).
The code is below
InitialContext context=new InitialContext();
Object objRef=context.lookup("corbaname:iiop:andaman:33703#ejb/PaymentEJB");
I am getting the following error.
[#|2005-12-14T16:42:03.422+0530|SEVERE|sun-appserver-pe8.1_02|javax.enterprise.resource.corba._DEFAULT_.rpc.transport|_ThreadID=11;|"IOP00410216: (COMM_FAILURE) Unable to create IIOP listener on the specified host/port: all interfaces/3700"
org.omg.CORBA.COMM_FAILURE: vmcid: SUN minor code: 216 completed: No
at com.sun.corba.ee.impl.logging.ORBUtilSystemException.createListenerFailed(ORBUtilSystemException.java:2661)
My doubt is
1.While starting domain1 and domain2 iiop listeners are started on the port 3700 and 33703.in that case why EJB lookup tries to create listener on one more time.
2.I am looking the 33703 port only.but it tries to create port on 3700 why?
3.It was working till JES2005Q1.Is there any patch i need to install? or i need to change anything in my code.
I am frustrated with this error for past one week.I will be happy if some body will give me the peace of mind(thru some solution).

Hi,
I am having two different domain (domain1,domain2) respectvely. My ABC.ear j2eee application is deployed on domain2 and its iiop port is 33703.In domain1 i have xyz.war (web application) and it's IIOP port is 3700 .In xyz.war i am having CallEJB.jsp file.In this Jsp file i want to lookup an EJB Service called PaymentEJB(JNDI Name is ejb/PaymentEJB).
The code is below
InitialContext context=new InitialContext();
Object objRef=context.lookup("corbaname:iiop:andaman:33703#ejb/PaymentEJB");
I am getting the following error.
[#|2005-12-14T16:42:03.422+0530|SEVERE|sun-appserver-pe8.1_02|javax.enterprise.resource.corba._DEFAULT_.rpc.transport|_ThreadID=11;|"IOP00410216: (COMM_FAILURE) Unable to create IIOP listener on the specified host/port: all interfaces/3700"
org.omg.CORBA.COMM_FAILURE: vmcid: SUN minor code: 216 completed: No
at com.sun.corba.ee.impl.logging.ORBUtilSystemException.createListenerFailed(ORBUtilSystemException.java:2661)
My doubt is
1.While starting domain1 and domain2 iiop listeners are started on the port 3700 and 33703.in that case why EJB lookup tries to create listener on one more time.
2.I am looking the 33703 port only.but it tries to create port on 3700 why?
3.It was working till JES2005Q1.Is there any patch i need to install? or i need to change anything in my code.
I am frustrated with this error for past one week.I will be happy if some body will give me the peace of mind(thru some solution).

EJB Doubt

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