Can anyone describe using entity beans for persitance in Software Architect

Can anyone describe using entity beans for persitance in Software Architecture you built for a product?

Although this forum is supposed to help you gain knowledge on entity beans, its not a free rider that's supposed regurgitate everyone's knowledge to you.
Read something first and then clarify your thoughts with this forum.

Similar Messages

Can anyone give me a bean for JAVAMAIL in JSP?

Can anyone give me a bean for JAVAMAIL in JSP?
I'd like to use a bean instead of writing a complete jsp page for each of my send mail options!!

Have a look in the javaMail forum, youll find code for a class in there without too much trouble.

Data Warehouse report query using Entity Beans

I have used the EJB technology on one project, so I am not all that familiar with
best practices.
In my new project, I have to produce reports using a query that goes against a
dimensional database. I am wondering what options I have to run the query and
extract the results given that the application will run on WebLogic.
1) Straight JDBC
2) BMP
3) CMP (could be a problem because the quety is a join query, but I am not sure
if WebLogic requires that the query is against a table rather than a view)
The query is read-only. I am more interested in ease of coding and code management
rather than application performance at this point because I think the query will
spend a relatively large time executing on the Oracle database.
I would like to hear the best practices to be employed in this case. Thanks very
much!
Ravi.

Don't use entity beans for this. Straight JDBC is not perfect either, but it
is preferable to entity beans for this type of work.
Peace,
Cameron Purdy
Tangosol, Inc.
Clustering Weblogic? You're either using Coherence, or you should be!
Download a Tangosol Coherence eval today at http://www.tangosol.com/
"Ravi Navanee" <[email protected]> wrote in message
news:3c92693d$[email protected]..
>
I have used the EJB technology on one project, so I am not all thatfamiliar with
best practices.
In my new project, I have to produce reports using a query that goesagainst a
dimensional database. I am wondering what options I have to run the queryand
extract the results given that the application will run on WebLogic.
1) Straight JDBC
2) BMP
3) CMP (could be a problem because the quety is a join query, but I am notsure
if WebLogic requires that the query is against a table rather than a view)
The query is read-only. I am more interested in ease of coding and codemanagement
rather than application performance at this point because I think thequery will
spend a relatively large time executing on the Oracle database.
I would like to hear the best practices to be employed in this case.Thanks very
much!
Ravi.

Can anyone give me a bean class for JAVAMAIL, for using in JSP?

Can anyone give me a bean class for JAVAMAIL, for using in JSP?
I hate coding everything inside a jsp page!! Anyone out there who can help me out??

hi
see my post in the javamail forum... here you can see a bean.. I'm trying to connect it with the mysql database - may you can help me

I cannot afford an iMac, can anyone recommend a widescreen Monitor for my 15" MacBook Pro. It would be used mainly for iPhoto and Aperture.

I cannot afford an iMac, can anyone recommend a widescreen Monitor for my 15" MacBook Pro. It will be used mainly for iPhoto and Aperture. TF

Pair a wireless KB with the laptop and all should be well when you attach the laptop to the iMac and invoke TDM. But as Denny mentions, it does seem like the waste of a good iMac to use it in just this configuration. Why is the laptop primary?

Entity bean for shared acces without database access

Hi all,
I would like to create an entity bean to store data common for all application users. This bean does not have to have a database link, it should only keep data in memory until no user left.
Is it possible ? And if yes, how ?
I have already created a session bean that works but only keep data for one users session, and I have created an entity bean but it seems that it requires a database link.
Thanks
Sylvain

Sylvain,
I am assuming that you are using webdynpro for this.
You have a provision to use 'Dictionary' objects to handle CRUD operations in webdynpro and also at EJB level.
I can suggest you to handle this scenario in two ways.
1) If you are trying to perform the persistance at Webdynpro level, You can create the dictionary object straightaway in the webdynpro component.
2) If you are trying to perform persistance at EJB level using entity bean, I suggest you to maintain/create a dictionary object using your NWDS and access that Dictionary object at your entity bean using dictionary by packagename. Ofcourse you may have to write the CRUD operations code by urself.
I hope that this information would be most useful.

[persistence] all work, but can't persist new entity bean

Hi,
I have a FacadeBean which is working fine ... I can contact the BD oracle for retrieving my entity beans, update an entity bean etc...
BUT... I can't create an entity bean :( I don't understand why!!!
With the same code, I can create, list, etc... on OC4J and JBoss but the create method won't work with WebLogic :|
Here is the error present in console:
<09-mars-2007 15 h 03 min 47 s CET> <Error> <EJB> <BEA-010026> <Exception occurr
ed during commit of transaction Name=[EJB be.starapic.test.ejb.MyEntityFacadeBea
n.create(be.starapic.test.ejb.MyEntity)],Xid=BEA1-007A82AF3A953057A4BD(30283302)
,Status=Rolled back. [Reason=weblogic.transaction.internal.AppSetRollbackOnlyExc
eption],numRepliesOwedMe=0,numRepliesOwedOthers=0,seconds since begin=1,seconds
left=30,XAServerResourceInfo[weblogic.jdbc.wrapper.JTSXAResourceImpl]=(ServerRes
ourceInfo[weblogic.jdbc.wrapper.JTSXAResourceImpl]=(state=rolledback,assigned=Ad
minServer),xar=weblogic.jdbc.wrapper.JTSXAResourceImpl@110563c,re-Registered = f
alse),SCInfo[base_domain+AdminServer]=(state=rolledback),properties=({weblogic.t
ransaction.name=[EJB be.starapic.test.ejb.MyEntityFacadeBean.create(be.starapic.
test.ejb.MyEntity)], weblogic.jdbc=t3://192.168.100.188:7001}),OwnerTransactionM
anager=ServerTM[ServerCoordinatorDescriptor=(CoordinatorURL=AdminServer+192.168.
100.188:7001+base_domain+t3+, XAResources={weblogic.jdbc.wrapper.JTSXAResourceIm
pl},NonXAResources={})],CoordinatorURL=AdminServer+192.168.100.188:7001+base_dom
ain+t3+): weblogic.transaction.RollbackException: Unknown reason
at weblogic.transaction.internal.TransactionImpl.throwRollbackException(
TransactionImpl.java:1808)
at weblogic.transaction.internal.ServerTransactionImpl.internalCommit(Se
rverTransactionImpl.java:333)
at weblogic.transaction.internal.ServerTransactionImpl.commit(ServerTran
sactionImpl.java:227)
at weblogic.ejb.container.internal.BaseRemoteObject.postInvoke1(BaseRemo
teObject.java:606)
at weblogic.ejb.container.internal.BaseRemoteObject.postInvokeTxRetry(Ba
seRemoteObject.java:426)
at weblogic.ejb.container.internal.StatefulRemoteObject.postInvokeTxRetr
y(StatefulRemoteObject.java:100)
at be.starapic.test.ejb.myentityfacade_opn58i_MyEntityFacadeRemoteImpl.c
reate(myentityfacade_opn58i_MyEntityFacadeRemoteImpl.java:158)
at be.starapic.test.ejb.myentityfacade_opn58i_MyEntityFacadeRemoteImpl_C
BV.create(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at weblogic.ejb.container.internal.RemoteBusinessIntfProxy.invoke(Remote
BusinessIntfProxy.java:42)
at $Proxy152.create(Unknown Source)
at be.starapic.test.web.HelloServlet.doGet(HelloServlet.java:88)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run
(StubSecurityHelper.java:226)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecuri
tyHelper.java:124)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.jav
a:283)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.jav
a:175)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationActio
n.run(WebAppServletContext.java:3334)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(Authenticate
dSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(Unknown Source)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppS
ervletContext.java:2081)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletC
ontext.java:1987)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.j
ava:1359)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:200)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:172)
.>
<09-mars-2007 15 h 03 min 47 s CET> <Error> <HTTP> <BEA-101020> <[weblogic.servl
et.internal.WebAppServletContext@144a314 - appName: 'testDeploy', name: '/testDe
ploy', context-path: '/testDeploy'] Servlet failed with Exception
javax.ejb.EJBException: nested exception is: weblogic.transaction.internal.AppSe
tRollbackOnlyException
at weblogic.ejb.container.internal.RemoteBusinessIntfProxy.invoke(Remote
BusinessIntfProxy.java:57)
at $Proxy152.create(Unknown Source)
at be.starapic.test.web.HelloServlet.doGet(HelloServlet.java:88)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
Truncated. see log file for complete stacktrace
That say nothing good...
at $Proxy152.create(Unknown Source) is the problem I think but why ...?
Here is the entity bean:
@Entity
@Table(name="table_myentity")
public class MyEntity implements Serializable
private static final long serialVersionUID = -5806278646729410835L;
private int id;
private String name;
private int number;
public void setName(String name) {
this.name = name;
public String getName() {
return name;
public void setNumber(int number) {
this.number = number;
@Column(name="mynumber")
public int getNumber() {
return number;
public void setId(int id) {
this.id = id;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public int getId() {
return id;
May be a problem of auto-generate for the ID...
Here is the facade bean:
@Stateful(name="myentityfacade", mappedName="myentityfacade")
@Remote(MyEntityFacadeRemote.class)
@Local(MyEntityFacadeLocal.class)
public class MyEntityFacadeBean implements MyEntityFacadeRemote, MyEntityFacadeLocal {
@PersistenceContext
private EntityManager em;
public MyEntity create(MyEntity meb) {
em.persist(meb);
return meb;
public void update(MyEntity meb) throws IllegalAccessException {
if (null == em.find(MyEntity.class, meb.getId())) {
throw new IllegalAccessException("Attempt to update a non existing entity");
em.merge(meb);
public void delete(int id) {
MyEntity meb = em.find(MyEntity.class, id);
em.remove(meb);
public void delete(MyEntity meb) {
meb = em.merge(meb);
em.remove(meb);
public MyEntity findById(int id) {
return em.find(MyEntity.class, id);
public List<MyEntity> listAll() {
return em.createQuery("SELECT o FROM MyEntity AS o").getResultList(); //TOPLINK, HIBERNATE
public List<MyEntity> listFiltered(String filter) {
return em.createQuery("SELECT o FROM MyEntity AS o "+filter).getResultList(); //TOPLINK, HIBERNATE
public int getNbMyEntityBean() {
return this.listAll().size();
Sorry for the long post... And finnaly here is the code present in the servlet:
// CREATE
MyEntity meb1 = new MyEntity();
meb1.setName("bbb");
meb1.setNumber(2);
meb1 = remoteMyEntityFacade.create(meb1);
Note that the remoteMyEntityFacade is working, because I can call any other buisness method without crashing the application.. Just the create can't work and so, persistence can't be used :(
Any suggestions ?

There is a problem with generated key
that code won't work:
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public int getId() {
return id;
But, if I remove line "GeneratedValue", it can insert into the BD, once only :s
The ID is set to 0 by default, so I can't add more than one entity :s

Disadvantages of using entity beans.

can I know the disadvantages of using entity beans.

sigh I guess if someone puts it on a website it must be true...
"Forces the use of a heavy component mechanism for fine grained business objects."
Heaviness is not some arbitrary side-effect. It is directly due to the services provided by the EntityBeans (transactions, etc). If you need those services, you pay the price. If you don't then you shouldn't be using EJB to begin with. Also with the advent of LocalInterfaces, fine-grainedness is no longer a liability.
"More complex than JDO limiting developer productivity."
Perhaps it has less to do with limited productivity, and more to do with limited developers.
"More difficult to achieve good performance."
Compared to a simple data storage mechanism, sure.
"Inheritance not supported."
Really? Wow, I guess all the EJB code I've written for the last 3 years doesn't really work.
"Cannot be used for persistence in non-application server environments."
Uhh, yeah, but seeing as how the decision to use EJBs is not limited to the persistance scheme, the non-use of an application server is moot.
"There is no dynamic query mechanism to lookup entity beans (finders are specified at compile time)."
And what compiled business process (i.e SessionBeans) requires dynamic lookup of arbitrary data? Humans performing search functions can be done via entity beans, but probably should not be done since a large searches do not (or very rarely) need to be transactional.
"It is not easy to write unit tests for beans as it is not possible to use them outside of the application server."
For a long time this was true, but there are now many unit test suites designed for J2EE.
"No support for automatic primary key generation."
In the spec, no. But it's fairly trivial to implement on your own.
"Only relational databases are supported."
If you use CMP, yes. If you use BMP, you can do whatever you want inside your ejbLoad()/ejbStore() methods. Another reason to not use CMP.

When i connect my iphone 4,an error message saying usb device is malfunctioning is appearing...can anyone give me a solution for this?

when i connect my iphone 4,an error message saying usb device is malfunctioning is appearing...can anyone give me a solution for this?i tried using on a different pc.but still get the same result..

First thing i would try is to use another cable if available.

Insert data into table from JSP page using Entity Beans(EJB 3.0)

I want to insert data into a database table from JSP page using Entity Beans(EJB 3.0).
1. I have a table 'FRIENDS', (in Oracle 10g database).
2. It has two columns, 'NAME' and 'CITY'. Both have datatype strings(varchar2).
3. Now from a JSP page, having two textfields, 'NAME' and 'CITY', I want to insert data into table 'FRIENDS'.
4. In between JSP and database is a Entity Bean(EJB 3.0) and a stateless session bean.
5. I am using JDev as editor.
Please provide me code ASAP or link with similar example.
Thank you.
Anurag

Hi,
I am also trying that scenario. So u can
Post the jsp form data to a Servlet which will act as a Controller.
In the servlet invoke the business method.
Similar kind of app is in www.roseindia.net
Hope this would help u.
Meanwhile if u get any optimal solution, pls post it.
Thanks,
Happy Java Coding.

Can anyone suggest a simple system for backing up my MacBook?

I have a MacBook 120G which runs Tiger. I also have an Aiport Extreme, which is connected to a printer via USB. I want to buy an external hard drive to create a safety back up of my whole system. I have been trawling the suppliers' websites, getting more and more confused. Can anyone suggest the simplest solution for a simple-minded user like me? These are my main confusions:
a) Can anyone suggest what type / make of hard drive I should buy in order to be able to store my computer's contents and re-boot it in the event of disaster? Will a non-powered hard drive do the job or is it somehow better to get a powered one? It would sit near my desk so I am keen to avoid fan noise if at all possible! I believe I'll need to 'partition' the drive in order to make it bootable, or something - if this is correct, what kind of hard drive is easiest and idiotproof for this?
b) I think I've concluded it's not worth binning my Airport Extreme and replacing it with a Time Capsule. But is it worth buying Leopard in order to get Time Machine? I believe I can still use the Airport Extreme to connect to the hard drive so that Time Machine would make backups regularly and wirelessly? If so, do I need to use a USB hub from the Airport Extreme so that I can still keep the printer connected? I can only find one HD which has a built in hub - the Iomega Minimax - but I have read reviews saying the fan is noisy. Any other suggestions?
Any help and suggestions about this would be very gratefully received. Many thanks
Steve

Leopard is a nice upgrade (if your computer has 2GB of memory) and TimeMachine is convenient but it isn't the only way to create a reliable and simple backup system. If you decide TM is your solution buy a drive that has 2 to 3 times as much space as you are using on your computer now. If you are using 80GB of your drive now, buy a 160GB to 240GB drive for TimeMachine. It keeps multiple backups and eats up drive space pretty quickly.
Lots of good backup programs exist but the one I really like is called SuperDuper! It will create an exact duplicate of your hard drive and you can set up a schedule so that automatically backs up new and modified files at specific times/days. With my MacBook I connect it to my external drive on Friday evening and let SuperDuper! do its work overnight. If you chose this router or another that doesn't use TimeMachine, get a drive at least as large as your computer's hard drive.
The Western Digital MyBook series is a good choice and so is the Seagate FreeAgent series. I'd avoid self powered external drives like Western Digital's Passport series unless you intend to travel with the drive. They require special proprietary cables to power the drive which are easy to lose and expensive to replace, among other things. If you can afford a firewire drive that's generally preferable because firewire is faster than USB but the speed difference isn't blazing. If you do you backing up over night speed won't be an issue.
Whether you use TimeMachine or another program, this is just once phase of a backup plan. If you experience a break-in, fire, or flood the backup drive is probably going to experience the same fate as your computer. You also need to think about taking a backup of your most important files off-site. This can be as simple as once a month burning a DVD of your documents, digital photos, and email to a DVD and taking it to work.

My BB9810 refuse to load OS7.1 software on my phone after the download has completed. My phone has freezed/stucked since morning. Pls urgent help/assistant needed as I can not access/use my phone for over 24hrs now.

My BB9810 refuse to load OS7.1 software on my phone after the download has completed. My phone has freezed/stucked since morning. Pls urgent help/assistant needed as I can not access/use my phone for over 24hrs now.

Hi there,
Use the method described in the link below to get back up and running:
http://supportforums.blackberry.com/t5/Device-software-for-BlackBerry/How-To-Reload-Your-Operating-S...
I hope this info helps!
If you want to thank someone for their comment, do so by clicking the Thumbs Up icon.
If your issue is resolved, don't forget to click the Solution button on the resolution!

Can anyone give me some documents for data cluster

Hi,
can anyone give me some documents for data cluster?
ths!
regards!

Hi ,
The following is a documentation on the Data Cluster:
Data clusters are specific to ABAP. Although it is possible to read a cluster database using SQL statements, only ABAP can interpret the structure of the data cluster.
You can store data clusters in special databases in the ABAP Dictionary. These are called ABAP cluster databases, and have a prescribed structure:
Cluster Databases ( I have explained the cluster databse below )
This method allows you to store complex data objects with deep structures in a single step, without having to adjust them to conform to the flat structure of a relational database. Your data objects are then available systemwide to every user. To read these objects from the database successfully, you must know their data types.
You can use cluster databases to store the results of analyses of data from the relational database. For example, if you want to create a list of your customers with the highest revenue, or an address list from the personnel data of all of your branches, you can write ABAP programs to generate the list and store it as a data cluster. To update the data cluster, you can schedule the program to run periodically as a background job. You can then write other programs that read from the data cluster and work with the results. This method can considerable reduce the response time of your system, since it means that you do not have to access the distributed data in the relational database tables each time you want to look at your list.
Cluster Database :
 Cluster databases are special relational databases in the ABAP Dictionary that you can use to store data clusters. Their line structure is divided into a standard section, containing several fields, and one large field for the data cluster.
Creating a Directory of a Data Cluster
To create a directory of a data cluster from an ABAP cluster database, use the following statement:
Syntax
IMPORT DIRECTORY INTO <dirtab>
 FROM DATABASE <dbtab>(<ar>)
 [CLIENT <cli>] ID <key>.
This creates a directory of the data objects belonging to a data cluster in the database <dbtab> in the internal table <dirtab>. You must declare <dbtab> using a TABLES statement.
To save a data cluster in a database, use the EXPORT TO DATABASE statement .
For <ar>, enter the two-character area ID for the cluster in the database. The name <key> identifies the data in the database. Its maximum length depends on the length of the name field in <dbtab>. The CLIENT <cli> option allows you to disable the automatic client handling of a client-specific cluster database, and specify the client yourself. The addition must always come directly after the name of the database.
The IMPORT statement also reads the contents of the user fields from the database table.
If the system is able to create a directory, SY-SUBRC is set to 0, otherwise to 4.
The internal table <dirtab> must have the ABAP Dictionary structure CDIR.
******** Sample Program illustrating the data cluster .
PROGRAM Zdata_cluster.
TABLES INDX.
******to save data objects in cluster databases
DATA: BEGIN OF ITAB OCCURS 100,
 COL1 TYPE I,
 COL2 TYPE I,
 END OF ITAB.
DO 3000 TIMES.
ITAB-COL1 = SY-INDEX.
ITAB-COL2 = SY-INDEX ** 2.
APPEND ITAB.
ENDDO.
INDX-AEDAT = SY-DATUM.
INDX-USERA = SY-UNAME.
INDX-PGMID = SY-REPID.
EXPORT ITAB TO DATABASE INDX(HK) ID 'Table'.
WRITE: ' SRTF2',
 AT 20 'AEDAT',
 AT 35 'USERA',
 AT 50 'PGMID'.
ULINE.
SELECT * FROM INDX WHERE RELID = 'HK'
 AND SRTFD = 'Table'.
WRITE: / INDX-SRTF2 UNDER 'SRTF2',
 INDX-AEDAT UNDER 'AEDAT',
 INDX-USERA UNDER 'USERA',
 INDX-PGMID UNDER 'PGMID'.
ENDSELECT.
****To create a directory of a data cluster from an ABAP ****cluster database
DATA DIRTAB LIKE CDIR OCCURS 10 WITH HEADER LINE.
IMPORT DIRECTORY INTO DIRTAB FROM DATABASE
 INDX(HK) ID 'Table'.
IF SY-SUBRC = 0.
WRITE: / 'AEDAT:', INDX-AEDAT,
 / 'USERA:', INDX-USERA,
 / 'PGMID:', INDX-PGMID.
WRITE / 'Directory:'.
LOOP AT DIRTAB.
 WRITE: / DIRTAB-NAME, DIRTAB-OTYPE, DIRTAB-FTYPE,
 DIRTAB-TFILL, DIRTAB-FLENG.
ENDLOOP.
ELSE.
WRITE 'Not found'.
ENDIF.
*******run this program and see the result.
Hope this documentation will give you an idea of data cluster.
if useful, do reward with the points.
Regards,
Kunal.

Is it Possible in JSF? Can anyone recommend any java Technology for this?

I am doing Post Graduate Degree in Computer Science. This is my final semester and doing project work.
Any body having idea about my requirment, help and guide to me
My description and questions are as follows:
Current Approach:
PHP has been used to achieve the flexibility of creating custom images on-the-fly. Using this approach we were able to create a web-interface similar to the application client, where we could display links and get the exact look and feel of the application client.
Drawback:
This approach forces us to use two different technologies Java and PHP, since our system uses 'Java' accessing all the API's from PHP becomes a problem. while PHP provides a way to invoke any java method. It comes with a draw back, the method calls are little slow. This delay's are loading of web-page.
Requirment:
1. Creating custom images on various locations of the screen
2. The Exact look and feel of the application map should be achieved
3. Place elements and links correctly as in application-client reflect any changes
4. Generation events on the Links and Elements
5. Setting Backgroud images for different maps
Questions:
1. is it possible in JavaServer Faces (BETA)?
2. If it is possible is JavaServer Faces(BETA) How to create custom images and create interfaces among them?
3.Can anyone recommend any java Technology for doing this?
Anybody having idea, help and guide me for doing my project

hi,
I think you can use JSF
cheers
Trajano

Can i create an entity bean to part of a table

Hi there,
I am using EJB 2.0.
Can i create an entity bean to part of a table.
Thanks
Edited by: vamseebobby on Nov 5, 2007 11:11 AM

of course,provided the other parts left out have not constraints.
sumelong

Can anyone describe using entity beans for persitance in Software Architect

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