Objects of EJB in flex

Hello.
i want know if is possible that i can use Java Objects in my flex application using Blaze-Ds.
I have all my business logic in Objects inside EJBs. Then, i need use it in a new flex application. I was read that i can do it, but i don't know how.
Thanks
Danilo
Santa Marta - Colombia

Hi there,
Shortly put: Flex Builder is not Dreamweaver and nor are the Flex applications like HTML web pages. You can't creat any templates with wizzards or whatsoever, especially because Flex isn't really used to create web sites but rich internet applications ( although a web site might fall into this category, the two are still quite different Worlds ). So, the most you can do is either to develop a skeleton web site that you can fill with components later on ( which in my opinion is just a waste of time ) or create many little and standalone components that you can reuse in each project ( and also in projects that might not have anything to do with web sites ).
If you are looking to create templates that you might have gotten used to in Dreamweaver ( or other softwares like DW ), then I think that nor Flash or Flex are the technologies for you ( especially not then if you are thinking of templates the same way when using these technologies as if you were using Dreamweaver/HTML templates ). Flex 4 did introduce "templates" but those templates do not really fall into this "website templates" category either ( if you want to read up on the what Flex 4 templates are then visit this page: http://livedocs.adobe.com/flex/gumbo/html/duplicate_1_WS52085436-ABD3-4d4d-B5E2-41C668CF68 47.html ).
With best regards,
Barna Biro

Similar Messages

Issues in mapping objects from java to flex - using flex4

Hi,
I have a class in java which i want to send to flex4 using BlazeDS as middleware. There are a few issues that i am facing and they are:
When sending the object across (java to flex), the properties with boolean data type having value as true gets converted to properties with value as false. Even after setting the value to true it still comes as false on flex side. Can't understand why this is happening.
When sending the list of object containing property with boolean data type, the object on flex side does not show those properties at all. As of there were no boolean properties in that object.
Last but not the least, When sending List<ContractFilterVO> contractFilterVOs to flex using remote call, the result typecasted to ArrayCollection does not show the holding objects as ContractFilterVOs but as plain default Object though having all the properties send, except the boolean one mentioned in above points. Basically it is not able to typecast the objects in arraycoolection but the same objects gets typecasted when sent individually.
In all the above points i am using Remote Service through BlazeDS for connectivity with Java. I have done a lot of this stuff in Flex 3 but doing it for the first time in flex 4, is there anything that Flex 4 needs specific. Below is the pasted code for reference purpose.
Flex Object
package com.vo
     [RemoteClass(alias="com.vo.ContractFilterVO")]
public class ContractFilterVO{
     public function ContractFilterVO(){
     public var contractCode:String;
     public var contractDescription:String;
     public var isIndexation:Boolean;
     public var isAdditional:Boolean;
* Rmote Part of code
var remoteObject:RemoteObject = new RemoteObject();
remoteObject.destination="testService";
remoteObject.addEventListener(ResultEvent.Result,handleResult);
public function handleResult(event:ResultEvent):void{
     var contarctFilterVOs:ArrayCollection = event.result as ArrayCollection; //Point 2&3 probelem, if list sent form java
     var contarctFilterVO:ContractFilterVO= event.result as ContractFilterVO; //Point 1 probelem, if only single Object of type ContractFilterVO sent form java
Java Object
package com.vo
public class ContractFilterVO implements Serializable
     public function ContractFilterVO(){
     private static final long serialVersionUID = 8067201720546217193L;
     private String contractCode;
     private String contractDescription;
     private Boolean isIndexation;
     private Boolean isAdditional;
I don't understand what is wron in my code on either side, it looks syntactically right. It would be great anyone could help me point out my mistake here. Waiting for right solutions...
Thanks and Regards,
Jigar

Hi Jeffery,
Thanks for your reply, it did solve my query @ point 3 as well as point 2 where the objects in arraycollection were not geting converted and boolean properties did not appear when list of an objects were received. And hey, i did have public functions for properties defined java class, just forgot to mention here in post, sorry for that.
The solution you gave was right, but than what if i have a VO which has multiple List of objects coming from Java, than i would have to create an instance of each type of object on flex side this is too tedious, is'nt it? Is there any better solution... out there.
And jeffery do you some tricks up your sleeve for this Boolean issues to that i am facing in point 1... Still struggling with this one...
Anyone out there would be more than welcome to point my mistake, if any and provide tips/tricks or solutions...
Thanks again to Jeffery...
Waiting for more solutions sooner...
thanks and Regards,
Jigar

ABAP Objects and EJB

Hi every one,
Can <b>ABAP Objects and EJB</b> be compared?
-Naveen.

Hi Naveen,
Check this guide- might be useful-
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/dc09af90-0201-0010-d09b-bd611a11070b
Regards,
Moorthy

About hanle object in ejb

Hello
What is role of handle object in ejb & how we can use .please give a suitable example.
Regards
Rajesh Pandey
j2ee developer
mob:--9811903737
email:-- [email protected]

A Handle is a serializable reference to a remote EJB. It can be saved and then used at a later time to obtain a reference to that specific EJB object (for example a specific entity bean corresponding to a specific database record). When the handle is used, it is a much quicker process. Instead of having to do something like:
javax.naming.Context context = new javax.naming.InitialContext();
Object ref = ctx.lookup("EmployeeHomeRemote");
EmployeeHomeRemote home = (EmployeeHomeRemote) PortableRemoteOjbect.narrow(ref,EmployeeHomeRemote.class);
EmployeeRemote employee = home.findByPrimaryKey(primaryKey);all you would have to do is:
Object ref = handle.getEJBObject();
EmployeeRemote employee = (EmployeeRemote) PortableRemoteObject.jarrow(ref,EmployeeRemote.class);Since you are avoiding the naming lookup, it is also much more efficient. You could use it if you need recurring access to a particular record such as a user's preferences record in a database. It can also be used to obtain references to session beans (such as a particular stateful session bean).

Transfer Objects in EJB 3.0

Hello,
I am building Enterprise application with EJB 3.0 and JSF. In many J2EE books there's that Trasfer Object pattern ( sometimes called Value Object or so), I just wonder what are your experiences in using TO in Java EE ( EJB 3.0).
Because entity beans in EJB 3.0 are POJOs I think that there is no need to
use TO pattern.
Im my app I receive entity from session bean and bind that entity to JSF components. This is the easisest solution for me because I don't build boring
transfer object, and don't have to wory about transformation between TO and Entity beans. Am I doing right or I am maybe missing something??
By reading EJB 3.0 spec. when session bean returns entity it becomes
detached so its just plain java object. ??
I know that using TO you can reduce coupling between client and EJB but
you must implement additional level with TO objects and transformations, so
it looks to me that by using TO you just get more complexity and problems ?
Tell me what are your thoughts and experiences.
Regards,
Niksa Jakovljevic
FOS

Hi Niksa,
Your intuition about EJB 3.0 is correct. One of the advantages of Java Persistence API entities
is that they can be passed directly to clients without having to convert their data to separate transfer
objects. The reason this was a common pattern in EJB 2.x and earlier is that CMP 2.x beans are 1st
class EJB components that are limited in their ability to be used outside of the ejb tier.
--ken

Passing complex object from JavaScript to Flex

Is it possible to call a Flex function (defined with ExternalInterface.addCallback) and pass a complex object from Javascript? The properties of the object are all simple types, but the object itself is an array of objects. For example:
<script type="text/javascript">
var arrayOfObj = [ { one: "one", two: 2, three: "blah" }, { one: "xyz", two: "abc", three: 3.141 } ];
callSomeFunctionInFlex(arrayOfObj);
</script>
What would I do on the Flex side to make this happen?

Complex object passing works as expected in Blazeds.
There are certain cases where you need to write custom bean proxy classes to marshall an object, but your case is very simple and will not require it.
Make sure that you set the full java package and class name in your remote alias statement on your client value object. The class has to be fully qualified. The AS value object also needs the correct import of the nested value object or you will get a compile error.
Make sure that the blazeds server has the full class path set to your java objects.
To debug, you can turn on Blazeds logging in the services-config.xml file like this:
   <logging>
        
        <target class="flex.messaging.log.ConsoleTarget" level="DEBUG">
            <properties>
                <prefix>[BlazeDS]</prefix>
                <includeDate>false</includeDate>
                <includeTime>false</includeTime>
                <includeLevel>true</includeLevel>
                <includeCategory>false</includeCategory>
            </properties>
        </target>
    </logging>

Returning cloned objects from EJB Local Interfaces

We'd like to let our WAS 5/J2EE container manage our transactions/unit of work. However, we don't want to have our objects serialized, so we intend to use LocalInterfaces. Additionally, we want to return value objects that support Toplink indirection such that we are not returning the actual cache object but instead a clone.Our question is, how do we return a cloned object that supports indirection from Toplink that we can later do a deepMergeClone on in an explicit update method?

Additional Information on the first post:
The pattern we've been testing is as follows:
1. We set up LocalInterfaces on our EJB's
2. The EJB Getters are using acquireNonSynchronizedUnitOfWork() to get a NON-JTS transaction to perform a readQuery. This results in a Cloned Bis object being generated. We then release the UOW and return the object.
3. The Returned Biz object Getters are using Indirection (probably using the released non-synchronized UOW).
4. The pattern for UPDATE is that we allow the Web Container code (servlet) to change the Cloned Biz Object, they then submit the CLONED and changed object to an EJB update() method where we use getClientSession().getActiveUnitOfWork() to link to the JTS transaction and perform a uow.deepMergeClone(bizObjectClone);
We are trying to use the pattern for the following reasons:
1. Isolation of the Cache to upper layers
2. Transaction Boundry is the EJB Container
3. We understand that there is a performance overhead with CLoned Biz Objects but this more mirrors the ValueObject Pattern then anything else we've tried.
BIG Question:
1. Is this a supported TopLink Pattern?
2. If its not supported, can it be?
3. Do you have any other suggested patterns?

Unable to map nested java classes and objects in actionscript using flex

Hi All..,
Im a newbie in flex and actionscripting...,I however have a task assigned in this domain and goin insane since a week now with this problem...
Problem explained:
I have a class called Unit that inturn have many other classes like for example unit has an engineer class,,,Im not able to access the attributes of engineer using the unit class...that is unit.engineer,engineerid is giving me a null...however attributes unique to unit are accessible...
Please help me out with this...,this problem has already eaten up my deadlines...
Any help would be appreciated and thankz in advance..

Thank you for the swift reply...,
I actually have three java classes Unit , Engineer and UnitretrievalRemote....
Unit contains engineer and also UnitRetrievalRemote has methods to retrieve unit which inturn should return engineer...,However i hav actionscript classes for both engineer and unit and mapped it apporopriately using the remotetag...and also my remote object is defined with a destination...
The below code is my Actionscripting code included in mxml:
import UnitScript.Engineer;//These are my Action Scripting Classes
import UnitScript.Unit;
import mx.collections.ArrayCollection;
import mx.collections.ArrayList;
import mx.controls.Alert;
import mx.events.FlexEvent;
import mx.rpc.events.ResultEvent;
public var unitIds:ArrayCollection;//I'm passing an array from java end
that retrieves the unitId's from the db using hibernate...
public var index:int;
public var unit:Unit;
protected function initData():void
ApplicationService.getUnitIds();
//This is the remoteobject call using blazeds to load the method during application start from java..
private function setUnitIds(event:ResultEvent):void
unitIds = ArrayCollection(event.result);
private function setUnit(event:ResultEvent):void
unit = Unit(event.result);
//mx.controls.Alert.show( "Compling" );
//mx.controls.Alert.show( "Engineer Method" +unit.engineerId);
//mx.controls.Alert.show( " Engineer=="+unit.engineer) ;
unitIDText.text = String( unit.unitId );
customerName.text = unit.name;//displaying the contents fetched from the backend in the panel...
setEngineer(event);
private function setEngineer(event:ResultEvent):void
unit.engineer = Engineer(event.result);
unit = Unit(event.result);
eng_id.text = String(unit.engineer.engineerId);
mx.controls.Alert.show( "Engineer ID Please Show"+unit.engineer);
//This prints a null.
mx.controls.Alert.show( "Direct Engineer Id" +unit.engineer.category);
// This prints a null.
Remote object mapping is as below:
<mx:RemoteObject
    id="ApplicationService"
    destination="Destination1" >
    <mx:method name="getUnitIds" result="setUnitIds(event)"
    fault="mx.controls.Alert.show(event.fault.faultString)"/>
    <mx:method name="getUnit" result="setUnit(event)"
    fault="mx.controls.Alert.show(event.fault.faultString)"/>
</RemoteObject>

Can I use ' ', ' ', '= ' and ' =' with java.sql.Timestamp objects in EJB-QL

ie. Is this valid?
<query>
<description>Find data between dates</description>
<query-method>
<method-name>findMetricsByDate</method-name>
<method-params>
<method-param>java.sql.Timestamp</method-param>
</method-params>
<method-params>
<method-param>java.sql.Timestamp</method-param>
</method-params>
</query-method>
<result-type-mapping>Local</result-type-mapping>
<ejb-ql>
SELECT OBJECT (o) FROM MetricResults AS o WHERE MetricResults.date > ?1 AND MetricResults.date < ?2
</ejb-ql>
</query>

No. Not with current EJB 2.0 CMP specs at least. Later revisions are supposed to fix this, but for now, this seriously limits the usefulness of EJB-QL.
.P.

Adding itemCreationPolicy="immediate" on mx:Panel causes null object reference error in Flex 4.x

The itemCreationPolicy works fine with spark components and other mx component until we hit by mx panel.
Looks like an error is thrown from StyleProtoChain.
The interesting thing is the null object reference error both occurs in Flex 4.0 and Flex 4.1, but caused by different objects.
Is there a workaround to use itemCreationPolicy on mx panel?
Thank you.

Yes, there are all kinds of problems when you remove something from the screen that had focus (for instance, at that point you can't capture keyboard events either).
My code is sprinkled with so many things to make sure something is in focus, I tend to forget that I've done it.
In your code that changes the currentState, add
this.setFocus()
HTH;
Amy

Problem in getting Home object of EJB in WebLogic 6.1

Hello,
I have deployed my stateless session bean with remote interfaces on my weblogic server but when i tried to access it from my client which is also present in the same application (ear) then it gives the following exception.
java.lang.ExceptionInInitializerError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:42)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:30)
at java.lang.reflect.Constructor.newInstance(Constructor.java:277)
at java.lang.Class.newInstance0(Class.java:301)
at java.lang.Class.newInstance(Class.java:254)
at javax.rmi.CORBA.Util.createDelegateIfSpecified(Util.java:342)
at javax.rmi.CORBA.Util.<clinit>(Util.java:54)
at javax.rmi.PortableRemoteObject.createDelegateIfSpecified(PortableRemoteObject.java:182)
at javax.rmi.PortableRemoteObject.<clinit>(PortableRemoteObject.java:61)
at jsp_servlet.__login._jspService(__login.java:123)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:265)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:200)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:2495)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
Caused by: java.lang.RuntimeException: could not find or instantiate any UtilDelegate class
at weblogic.iiop.UtilDelegateImpl.<clinit>(UtilDelegateImpl.java:73)
... 18 more
My code is like :
UserRegistrationHome loginuser;
Context initial = new InitialContext();
Object objref = initial.lookup("ejb/SimpleUserRegistration");
loginuser =(UserRegistrationHome) PortableRemoteObject.narrow(objref,UserRegistrationHome.class);
UserRegistration userlogin = loginuser.create();
It comes at line with PortableRemoteObject.......
Will some one help me in this regard, as why this exception generally comes and in what settings....
Thanks in advance.
SAC

Can you tell me how resolve the problem?
Thanks,
Michael
[email protected]

Passing object to EJB

Hi, I had a serializable data transfer object and i tried to pass into my session bean such as
public java.util.List retrieveCaseData(CASBasicDTO caseBasicDTO) throws Exception and i have this
error : java.lang.ClassCastException
It is very wierd. I tried to declare a new DTO inside my EJB, it works,but it give me an error when i try to pass in and out the DTO object. I half suspect is something to do with the RMI stuffs, but I don't know how to go about it to solve this problem.
Your advise is greatly appreciated. Thanks a lot!! :)

Do not hard-code the serial ID into your Objects - since you're dealing with remote calls, it's absolutely critical that the Objects on each side of the remote invocation be the exact same "version" of the Object. If they're not the same, you can/will get a marshalling-type exception, not a ClassCastException.

ClassCastException - While type casting Home object after EJB JNDI Lookup

Sun One Application Server throws a ClassCastException when I try to type cast Home object to it's respective interface type.
Here is the code ---
==============================================
Object obj = PortableRemoteObject.narrow( context.lookup( jndiName ), homeClass);
System.out.println("Remote Object - obj : "+obj);
if (obj != null) {
   System.out.println("obj.getClass().getName() : "+obj.getClass().getName());
   System.out.println("obj.getClass().getSuperclass() : "+obj.getClass().getSuperclass());
   Class[] interfaces = obj.getClass().getInterfaces();
   if (interfaces != null) {
      for (int count = 0; count < interfaces.length; count++) {
         System.out.println("interfaces[ " + count + " ].getName() : " + interfaces[ count ].getName());
}==============================================
The class name is dislpayed as the Stub class name.
While displaying the interfaces, the Home Interface name is displayed.
But later when I try to type cast it into Home Interface type, it throws a ClassCastException.
Can somebody please check this?

Please post the stack trace. Also, take a look at our EJB FAQ to make sure you're doing the
recommended lookup :
https://glassfish.dev.java.net/javaee5/ejb/EJB_FAQ.html

Default Connection Object in EJB

When we use default connection to get a connection to the oracle database through a deployed EJB, it uses the internal driver or in short it returns the same connection object. Is this connection object synchronized and thread safe. I mean if multiple people access this EJB at once, will it be fine or will the connection crash or some exception is thrown.

Either pass them as parameters or make them into member variables.

Passing connection object as EJB parameter

I am working on a legacy website which uses stateless session EJB's and runs on
WebLogic 6.1 using JDK 1.3 and Oracle 8.1.6, I am working on upgrading this
application to WebLogic 9.2, JDK 1.5 and Oracle 10.2.
I configured a datasource in WebLogic using the Oracle thin XA driver.
When attempting to run the application I got an error message stating that an
object which is not serializable is being passed as an EJB parameter. I found that
several EJB methods are passing open database connections as parameters so to fix this
issue we should change the code. However, I am reluctant to change the code since I
believe that the reason for passing the connection objects is that the developers
wished to preserve transactions and so any changes might result in many issues in
the application. I have the following questions:
- The code is doing something which is not allowed. So why was this okay in WebLogic
6.1 using the older Oracle oci driver?
- One way to get around this would be to convert the EJB's to POJOS. There are no
container based properties and the only EJB's are stateless session EJB's. The
high water mark for concurrant usage is 40. There is only a single server (no clustering)
What kind of issues would such a
conversion bring?
- Would it be better to convert the EJB's to local interfaces? What kind of issues would
this bring?
Any other suggestions would be very much appreciated.

Salma Saad wrote:
Thanks Joe,
Converting to POPJOS from EJB or to local EJB's is changing the code but it limits changes to the logic of the application which could result in unforseen issues.
There is only 1 server and 1 jvm but I get a not serlializable exception which I did not get when running this code on WebLogic 6.2 or 8.1 using Oracle 8.1.6 and 9i .I am getting it now that I am using WL 9.2 and Oracle 10.2.
I looked through all the parameters and everything is a string except for Connection which does not implement serializable. There is a Vector but all the contained objects are strings. Let me know if you have any ideas what I can do to get rid of this, and also why is it happenning in the newer version of WL when it didn't happen before?
weblogic.utils.AssertionError: ***** ASSERTION FAILED *****
     at weblogic.rmi.internal.CBVWrapper.copy(CBVWrapper.java:57)
     at com.isr.applications.isrinteractive.ejb.sessionbean.user.UserBean_x07h56_EOImpl_CBV.validateLogin(Unknown Source)
     at jsp_servlet._admin.__validatelogin._jspService(__validatelogin.java:187)
     at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)Hi. I looked at the code throwing this exception, and
it's in a whole 'nother area of the server, nothing to
do with JDBC or EJBs as such. It's odd too, because it
seems to have already verified that whatever object
it's dealing with is a serializable object...
I recommend you're opening an official support case
about this exception, and maybe they'll want help
reproducing it...
Joe
     at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:225)
     at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:127)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
     at weblogic.servlet.internal.ServletStubImpl.onAddToMapException(ServletStubImpl.java:391)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:309)
     at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at com.isr.applications.isrinteractive.servlets.reports.SessionFilter.doFilter(Unknown Source)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
     at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3212)
     at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
     at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
     at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:1983)
     at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1890)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1344)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:181)
Caused by: java.io.NotSerializableException: java.lang.Object
     at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1081)
     at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1375)
     at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1347)
     at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1290)
     at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1079)
     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:302)
     at weblogic.rmi.extensions.server.CBVOutputStream.writeObject(CBVOutputStream.java:84)
     at weblogic.rmi.internal.CBVWrapper.copy(CBVWrapper.java:49)
     ... 20 more

Objects of EJB in flex

Similar Messages

Maybe you are looking for