Remote client accessing ejb - question

This may be a very simplistic question, but here goes -
scenario: I have a J2EE application running on a server Y with session beans/entity beans.
I need a remote client on machine X to access EJB objects on Y.
I have set the initial conext with INITIAL_CONTEXT_FACTORY, PROVIDER_URL etc...
But, in order to narrow the reference of the object returned by lookup() method, I need to instantiate the Home object of my session (or entity) bean ...
here's my problem: How do I instantiate EJBHomeInterface or EJBRemoteInterface, when they do not exist on the remote client machine?? (does this have something to do with the stub??)
THANKS!

This answer assumes you're using Weblogic, although most any other EJB container has a facility for this. Basically you need to distribute a client jar file with the client. This client jar is created during the EJB compile/deployment process and creates a jar separate from the normal jar file associated with your deployment. This jar file contains the class stubs you need to call for and use EJB's on a remote client.
I hope this makes some sense.
SeanB

Similar Messages

Issues with remote client accessing EJB3

Hi folks,
I tested Weblogic 10.3 these days and had some trouble to access a stateless session bean (EJB3) via a remote Java client. My development system is Windows Vista 32bit.
First, Weblogic doesn't like blanks in folder names! The Test Client throws an exception complaining that the business interface is not found:
Exception in thread "Main Thread" java.lang.AssertionError: java.lang.ClassNotFoundException: ejb3session.Trader
at weblogic.ejb.container.internal.RemoteBusinessIntfGenerator.generateRemoteInterface(RemoteBusinessIntfGenerator.java:69)
at weblogic.ejb.container.internal.RemoteBusinessIntfProxy.readObject(RemoteBusinessIntfProxy.java:205)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
at weblogic.utils.io.ChunkedObjectInputStream.readObject(ChunkedObjectInputStream.java:197)
at weblogic.rjvm.MsgAbbrevInputStream.readObject(MsgAbbrevInputStream.java:564)
at weblogic.utils.io.ChunkedObjectInputStream.readObject(ChunkedObjectInputStream.java:193)
at weblogic.rmi.internal.ObjectIO.readObject(ObjectIO.java:62)
at weblogic.rjvm.ResponseImpl.unmarshalReturn(ResponseImpl.java:240)
at weblogic.rmi.cluster.ClusterableRemoteRef.invoke(ClusterableRemoteRef.java:348)
at weblogic.rmi.cluster.ClusterableRemoteRef.invoke(ClusterableRemoteRef.java:259)
at weblogic.jndi.internal.ServerNamingNode_1030_WLStub.lookup(Unknown Source)
at weblogic.jndi.internal.WLContextImpl.lookup(WLContextImpl.java:392)
at weblogic.jndi.internal.WLContextImpl.lookup(WLContextImpl.java:380)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at ejb3session.Client.lookup(Client.java:99)
at ejb3session.Client.(Client.java:34)
at ejb3session.Client.main(Client.java:61)
Caused by: java.lang.ClassNotFoundException: ejb3session.Trader
at weblogic.ejb.container.deployer.DownloadRemoteBizIntfClassLoader.getClassBytes(DownloadRemoteBizIntfClassLoader.java:85)
at weblogic.ejb.container.deployer.DownloadRemoteBizIntfClassLoader.loadClass(DownloadRemoteBizIntfClassLoader.java:46)
at weblogic.ejb.container.internal.RemoteBusinessIntfGenerator.generateRemoteInterface(RemoteBusinessIntfGenerator.java:66)
In fact, the compiled class file of the business interface is located on the file system in a path that contains a blank. Debugging session shows that the internal weblogic class RemoteBusinessIntfGenerator fails to open the class file because of a wrong used URL file reference. If the path contains no blank, everything works fine. This is obviously a bug!
Second, generics don't work in the business interface. As soon as I insert a generic return type or method parameter, I get an exception at runtime, no matter if the actually called method is generic or not:
java.lang.NullPointerException
     at weblogic.ejb.container.internal.RemoteBusinessIntfProxy.getTargetMethod(RemoteBusinessIntfProxy.java:162)
     at weblogic.ejb.container.internal.RemoteBusinessIntfProxy.invoke(RemoteBusinessIntfProxy.java:53)
     at $Proxy0.saveContact(Unknown Source)
     at Main.testIt(Main.java:45)
     at Main.main(Main.java:34)
Third problem is already known by Oracle (CR373734): when using JPA and serializing entities to the remote client, serialization fails until you implement a writeObject() method in every entity.
What is your experience concerning these issues? For my opinion quite severe bugs...
Cheers, Thomas

But most of the O/S like Linux ,Solaries does not allow blankspaces in the classpath. Only the O/S that does allow is Windows. and there are a lot of issues regarding the spaces in the classpath.
If a blank in the classpath exist in the admin console as a remote start argument for a managed node, a patch exist.its CR375981.
But for the above case 808498 (blank for remote client classpath) Engineering did not given any patch and asked to go with the work around ie not to use a blank in the classpath.
Thanks !!

Allow remote client access

Sorry if this has already been posted. I recently installed 3.1.2 on 10g xe and I am unable to find where I can allow access by remote clients. I remember on 2.1 that there was a section that allowed you to manage http-access. I've logged in as ADMIN and can't find it anywhere.

I needed to allow login page access by browser from another machine on the network. Setting this in sqlplus allowed me to enable that. To bring up the login page for the remote machine I use http://xxx.xxx.x.xxx:8080/apex as the url. Where xxx.xxx.x.xxx = ip address where APEX and 10g xe instance is running.

Applet clients accessing EJB middle-tier

Hello
I am trying to have an Applet access the stateless session EJBs on the middle tier (OC4J 9.0.3)
The applet works fine in the AppletViewer.
However in the IE browser version 5.5, I get java.security.AccessControlException.
Which I can understand because applet is not allowed to open a RMI-IIOP port on the remote server.
What steps do I need to take to allow the applet to open such a connection. Signing jars?, java.poclicy file ?
I know that this setup works fine on JBoss and also on WebSphere. (using certificates)
Is this not suported by OC4J? Does the server need to support something or is it strictly a client side issue?
Any comments will be highly appreciated.
Thanks
vijay

We are having Applet-clients with OC4J and it works fine. We sign all our client-jars (including oc4jclient.jar) and our application has all permissions at the client. Modifying java.policy works as well, but signing Jar-Files is simpler and doesn't need any client-changes.
For normal operations it seems ok to include oc4client.jar for the client application, but we are using JMS and therefore need a lot of classes of oc4j.jar - so I buildt my own deployment-jar out of oc4j.jar.
If you use the cache_archive and cache_version attributes in the html-tag, all the jar-files are only downloaded at application startup if they are changed on the server (und version-numbers are increased). So startup-time is comparable to a local application.
Gilbert

J2EE Tutorial With Remote Client

Where can I find a J2EE tutorial that demonstrates a remote client accessing an EJB? The Sun tutorial are all localized examples. Does a remote client have to run on a J2EE server?
Thanks,
-Ray

Remote Clients do not have to run in a J2EE server. All you need is the j2ee.jar and your app server's required runtime jar file(s) e.g oracle9iAS(oc4j.jar) and the .properties files.
Let me know if you need any more information.

Corba client to EJB on OAS408 ?

I have an EJB deployed on OAS408. Can I call the EJB methods from a Corba client? How will I setup a CORBA client to communicate RMI over IIOP ?
I found the following statement on the Oracle Java roadmap :
"Enterprise beans and Common Ojbect Request Broker Architecture (CORBA) clients can inter-operate with each other opening up the possibility of multiple types of clients accessing EJB servers accross the enterprise."
Can anybody please help me on how to do this
null

I am trying to do exactly the same thing
But I am unable to read the zip file on
the newsgroup.
Can someone mail me the zip of the sample
code.
Thanks inAdvance.
Irfan Lateef

REMOTE DESKTOP SERVICES CLIENT ACCESS LICENSES FOR MICROSOFT WINDOWS SERVER 2012 STANDARD AND DATACENTER

I am using a window 7 professional service pack 1 and I purchase REMOTE DESKTOP SERVICES CLIENT ACCESS LICENSES FOR MICROSOFT WINDOWS SERVER 2012 STANDARD AND DATACENTER. but the seller did not send me any installation CD or instruction
on how to use it.
Please how can I use it on my window 7 professional service pack 1.
Thank you.

Though Bill is absolutely correct for most CALs, Remote Desktop Services does have its own special licensing server. I haven't installed one on 2012, yet, but here is a step-by-step guide for 2008.
http://technet.microsoft.com/en-us/library/dd983943(v=ws.10).aspx
Here is a lab guide for 2012 -
http://technet.microsoft.com/en-us/library/jj134160.aspx
But, the explanation of your environment begs the question - what are you trying to do? You say you have a desktop OS and you are talking about Windows Server products. In that light, your question does not make a lot of sense.
. : | : . : | : . tim

EJB 3.0 Session Bean Remote Client

Hi,
I am planning to migrate my EJB 2.1 to EJB 3.0. My old session bean is accessed by a remote java client. I just have to include this piece of code:
Hashtable props = new Hashtable();
props.put("java.naming.factory.initial", com.sun.jndi.cosnaming.CNCtxFactory");
props.put("java.naming.provider.url", "iiop://" + host_ + ":" + port_);I also have to generate rmistubs for the ejb. I have deployed my EJB 3.0 in a Sun Appserver, checking the "Generate RMIStubs" box but I couldn't find the client jar file. In EJB 3.0, should I use the same approach as the 2.1? Or should I use the @EJB annotation? How will I access a remote EJB 3.0 using the @EJB annotation? Thanks in advance.
Regards,
Andrew
Message was edited by:
bashdrew

EJB 3.0 remote business interfaces are do not have the same interoperability requirements as the EJB 2.x Home/Remote view. If you need access to your EJB 3.0 bean from a legacy client, you can add a 2.x-style Home/Remote view to your bean by either using the <home>/<remote> elements in ejb-jar.xml or the @RemoteHome annotation. Note that the 2.x-style Home/Remote interfaces are completely separate from the 3.0 Remote Business interface.
Also, in SUN's implementation if your EJB 3.0 bean has both a 3.0 Remote business and a 2.x Home/Remote interface there is no default global JNDI name for the bean. You'll need to assign it explicitly using the @Stateless/@Stateful mappedName() attribute or sun-ejb-jar.xml.
--ken

Minimal requirements for remote client app to call a EJB 3 session bean

I'm just starting to get into EJBs, trying to learn the EJB 3 APIs. I kind of understand the setup on the server side to create a session bean. What I don't understand is what I would have to deploy for each of the remote client app (Swing-based GUI or something like that) installations. Of course, the client app code would have to be deployed to each client desktop, but what stuff related to the session bean? Just the session bean interface class?
For ease of discussion, let's say my bean is CalculatorBean, having two interfaces, CalculatorRemoteIface and CalculatorLocalIface. Let's also say my client app, CalculatorUI, is a simple Swing-based GUI that grabs a reference to a CalculatorBean.
Other than just the Swing-based classes and the JRE, what JARs/classes will I want to deploy to each desktop?
(Please assume the latest Sun Java System App Server 9 and Java EE 5, if you are familiar with them.)

Personally- I would deploy your backend
in EJB 3.0, but then expose it as a web service. It
is MUCH easier for your clients to connect to a web
service (and mantain that code), then to have them
connect via RMI/JNDI.Oh, I would say it's quite the opposite. RMI/JNDI is MUCH easier from a client point of view than web services. To make web services work easy from the client side you have to generate code and the tools that generate code from a web services wsdl file doesn't do a great job today. But that was not the question. But take some time reading this article about webservices...it's quite funny and spot on: http://wanderingbarque.com/nonintersecting/2006/11/15/the-s-stands-for-simple
Now to your question, yes you will need the remote interface on the client side.
/klejs

NotSerializableException accessing EJB 3 remotely

Hello everyone, thanks for reading...
I have an EJB3.0 application that runs on a OC4J 10.1.3.3
I have a remote client that needs of the ejb application services.
When the client tries to access the remote ejb services I get the : java.io.NotSerializableException, It's kinda odd because the class that is supposed to be Not Serrializable it's the Oracle's XML parser (oracle.xml.parser.v2.XMLError.)
Here's the first part of the stacktrace:
com.evermind.reflect.UndeclaredExceptionTypeException: oracle.oc4j.rmi.OracleRemoteException
     at __Proxy1.getUser(Unknown Source)
     at test.appclient.client.UserServiceEJBClient.main(UserServiceEJBClient.java:55)
oracle.oc4j.rmi.OracleRemoteException: Invocation error: java.rmi.UnmarshalException: Error deserializing exception-value: writing aborted; java.io.NotSerializableException: oracle.xml.parser.v2.XMLError; nested exception is:
     java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: oracle.xml.parser.v2.XMLError
     at com.evermind.server.rmi.RMICall.throwRecordedException(RMICall.java:142)
     at com.evermind.server.rmi.RMIClientConnection.obtainRemoteMethodResponse(RMIClientConnection.java:472)
     at com.evermind.server.rmi.RMIClientConnection.invokeMethod(RMIClientConnection.java:416)
     at com.evermind.server.rmi.RemoteInvocationHandler.invoke(RemoteInvocationHandler.java:63)
     at com.evermind.server.rmi.RecoverableRemoteInvocationHandler.invoke(RecoverableRemoteInvocationHandler.java:28)
     at com.evermind.server.ejb.StatelessSessionRemoteInvocationHandler.invoke(StatelessSessionRemoteInvocationHandler.java:43)
     at __Proxy1.getUser(Unknown Source)
     at test.appclient.client.UserServiceEJBClient.main(UserServiceEJBClient.java:55)
     Nested exception is:
java.rmi.UnmarshalException: Error deserializing exception-value: writing aborted; java.io.NotSerializableException: oracle.xml.parser.v2.XMLError; nested exception is:
     java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: oracle.xml.parser.v2.XMLError
     at com.evermind.server.rmi.RMICall.EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER(RMICall.java:110)
     at com.evermind.server.rmi.RMICall.throwRecordedException(RMICall.java:128)
     at com.evermind.server.rmi.RMIClientConnection.obtainRemoteMethodResponse(RMIClientConnection.java:472)
     at com.evermind.server.rmi.RMIClientConnection.invokeMethod(RMIClientConnection.java:416)
     at com.evermind.server.rmi.RemoteInvocationHandler.invoke(RemoteInvocationHandler.java:63)
     at com.evermind.server.rmi.RecoverableRemoteInvocationHandler.invoke(RecoverableRemoteInvocationHandler.java:28)
     at com.evermind.server.ejb.StatelessSessionRemoteInvocationHandler.invoke(StatelessSessionRemoteInvocationHandler.java:43)
     at __Proxy1.getUser(Unknown Source)
Here's the client code:
Properties props = new Properties();
// Standalone OC4J connection details
props.put( Context.INITIAL_CONTEXT_FACTORY, "oracle.j2ee.rmi.RMIInitialContextFactory" );
props.put( Context.SECURITY_PRINCIPAL, getUserContext().getUserCode() );
props.put( Context.SECURITY_CREDENTIALS, getUserContext().getUserCredentials() );
props.put(Context.PROVIDER_URL, "ormi://serverxxx:23791/UserServiceEjb");
try {
     InitialContext context = new InitialContext(props);
     UserService service = (UserService) context.lookup("UserServiceEJB");
     if (service!=null) {
          UserTO usr = service.getUser("root");
          System.out.println(usr);
} catch (InvalidDatabaseOperationException e) {
     e.printStackTrace();
} catch (ServiceException e) {
     e.printStackTrace();
} catch (NamingException e) {
     e.printStackTrace();
}catch (Exception e) {
     e.printStackTrace();
It's really weird the oracle.xml.parser.v2.XMLError thing, because it looks like the EJB is sending that exception...
Any hints would be very appreciated...
Thanks in advise...

Problem solved people.
OC4J includes in the classpath of all the deployed applications some inherited libraries like xmlparserv2.
xmlparsev2's XmlError exception doesn't seems to be Serializable.
So how did we solved the problem?
At deploy time we edited the classpath for the application and excluded the xml parser library. Now it finallly works.
Thanks to everyone.
Thanks jferman.

Access EJB's in JServer from MS COM clients

We need to access our EJB's from MS COM Clients (written in C++ currently using OCI)
Any suggestions ?
Thanks in Advance
null

I got the same problem.
Some posts here suggest you should put weblogic.jar under /common/lib,
I tried it but it didn't work. I also tried to put it under
webapps/yourweb/web-inf/lib
but it didn't work too. At last I had to unpack the weblogic.jar and put
them under
webapps/yourweb/web-inf/classes. This at least solved the problem you
mentioned.
I got other problem like ClassCastException that might be due to my own
code.
Anyway you can try the above approach. And please post your results here
just let
others know.
Thanks.
"Gary Bartlett" <[email protected]> wrote in message
news:3ce3fdf1$[email protected]..
>
Question -
Can anyone point me at documentation that will help me understand what jarfiles
are required to allow access EJB's that are deployed in Weblogic 6.1 froma Servlet
that is running under Tomcat.
I am currently getting the following exception:
javax.naming.NoInitialContextException: Cannot instantiate class:weblogic.jndi.WLInitialContextFactory.
>
>
>
Root exception is java.lang.ClassNotFoundException:weblogic.jndi.WLInitialContextFactory
atorg.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1394)
>
>
Thanks,
Gary Bartlett

Accessing EJB's from CORBA clients

Hi!
Can someone answer one badly important question?
Is it possible to access EJB's from CORBA clients directly, as if the
beans were ordinary CORBA objects? I mean DIRECT access - WIDHOUT
CORBA/Java server application as a liason between CORBA client and EJB
server!
I'm using WebLogic Enterprise 5.0.1.
Thanks in advance.
Aleksey.

Please reference a later posting on this very same question.
-- Lou Caraballo
Sr. Systems Engineer
BEA Systems Inc., Denver Telco Group
719-332-0818 (cell)
720-528-6073 (denver)
Aleksey Bukavnev <[email protected]> wrote in message
news:[email protected]..
Thank you!
Aleksey.
Bill Lloyd wrote:
There is a java to IDL mapping, which is quite complex. To use it, you
must
have an ORB which supports, at minimum, CORBA 2.3. ORBs I know of which
support this include Orbix 2000 for Java, Visibroker 4.0 for Java, and
Orbacus 4.0 for Java.
Also, check out the June 2000 "Java Report" which has an article onthis.
>>
To be perfectly honest, though, the best solution is to write a bridge,in
Java. One side is IDL, which CORBA clients use. The implementation ofthat
IDL makes RMI requests to get the necessary info. This solution willwork,
guaranteed. The portion of the spec for the java to IDL mapping isstill
quite new, and I would expect some, uh, "unexpected features" at thistime.
>>
-B
"Aleksey Bukavnev" <[email protected]> wrote in message
news:[email protected]..
Hi!
Can someone answer one badly important question?
Is it possible to access EJB's from CORBA clients directly, as if the
beans were ordinary CORBA objects? I mean DIRECT access - WIDHOUT
CORBA/Java server application as a liason between CORBA client and EJB
server!
I'm using WebLogic Enterprise 5.0.1.
Thanks in advance.
Aleksey.

Questions regarding Outlook Web App, Remote Desktop, Remote Web Access and VPN Access

Hi there,
I want to ask a series of questions regarding Outlook Web App, Remote Desktop, Remote Web Access and VPN access and was hoping whether you could help me. Below are my questions to ask you.
Outlook Web App - What do I need to configure in order to get my Exchange account to work with the OWA app on my iPhone? Is Office 360 required on the server that hosts Outlook Web App in our organisation? When I configure the settings and
connect I get the following message "couldn't connect - We couldn't connect to the server. Check your information and make sure it's correct." I can connect with other devices using Outlook Web App.
Remote Desktop - What do I need to configure in order to connect to my computer at work using Remote Desktop on my Windows Phone? When I configure the settings and connect I get the following message "Connection error - We couldn't connect
to the remote PC. Make sure the PC is turned on and connected to the network, and that remote access is enabled. Inquiring minds may find this error code helpful: 0x204" I can connect with other devices using Remote Desktop. There are currently no
RD Server settings in the Remote Desktop app on the Windows Phone and the only way I'm to connect to my PC at work is via Remote Desktop and not to be confused with the one by Microsoft, however the app is on a trial basis and times out every 5 minutes and
can only be used once every hour unless I purchased the app for £2.99 off the App Store but would ideally like to use the Microsoft Remote Desktop app though.
Remote Web Access - What do I need to configure in order to get Remote Web Access on my Windows Phone using a URL? When I log in using a URL I get the following message "There is a problem with this Web page. Please contact the person who manages
the server" I can connect with other devices using Remote Web Access. Also how do you enable the background option for Remote Web Access? I know how to do this in Remote Desktop but not in Remote Web Access. Remote Web Access works on PCs regardless
being onsite and offsite and on my iPhone, the same issue also occurs with my Nokia 5230s regardless of whether I'm using Opera Mobile or Mini or the latest Nokia Browser.
VPN access - How do you configure VPN access on a Windows Phone using VPN? I cannot find the protocols PPTP, L2TP, SSTP and IPsec in order to configure VPN access on the Windows Phone apart from IKEv2.
Many thanks,
RocknRollTim

Any help would be much appreciated.
Kind regards,
RocknRollTim

VNC access to remote clients assigned address from vpnclient ip pool

Hi,
I was wondering if anyone knows if it is possible to vnc to remote vpn clients that are assigned an address from a client IP pool defined on the pix.
The remote clients are using cisco vpn client, the access-list is a dynamic acl downloaded from a tacacs server.
thanks.

It is not possible to vnc to remote vpn clients that are assigned an address from a client IP pool defined on the pix

JClient accessing remote AppModule via EJB Session Fascade (BMT)?

Would appreciate some "how-to" advice on bootstrapping a remote JClient like the one in the VSM example,
such that: the JClient remotely accesses OC4J-pooled AppModule instances,
rather than creating a new AppModule instance on the client side.
In the OTN VSM-JClient example code, the Bootstrap is done in
AdministrativeServiceForm::main() as follows:
JUApplication app =
JUMetaObjectManager.createApplicationObject(
"VSMJClient.AdministrativeService",
null,
new JUEnvInfoProvider() );
String appModule =
System.getProperty("jclient.service",
"VSMJClient.AdministrativeService" );
The problem with this is -
JUMetaObjectManager.createApplicationObject() is undocumented, hence may or may not facilitate remote
App-Module access?
If anyone can share a working example of JClient remote AppModule access over ORMI (talking to modules deployed on JBuilder-embedded-OC4J), or can modify the VSM-JClient to do the same - it would be greatly appreciated!
Many thanks,
Lee.

JUMetaObjectManager.createApplicationObject("VSMJClient.AdministrativeService",null,new JUEnvInfoProvider());
looks for the Session AdministrativeService in VSMJClient.cpx:
<Session
Name="AdministrativeService"
Package="oracle.otnsamples.vsm.services"
Configuration="AdministrativeServiceLocal" >
</Session>
<Session
Name="RemoteAdministrativeService"
Package="oracle.otnsamples.vsm.services"
Configuration="AdministrativeService9iAS" >
</Session>
Just call
JUMetaObjectManager.createApplicationObject("VSMJClient.RemoteAdministrativeService",null,new JUEnvInfoProvider() );
to access the deployed Beans with configuration AdministrativeService9iAS.

Remote client accessing ejb - question

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