Interview Questions.

Q1. How Do I Publish An Xml Message?

Follow these steps:

Generate XML from the DOM record tree.

Serialize the generated DOM record to a StringWriter.

Call toString on the StringWriter and skip it into message.SetText.

Publish the message.

Q2. Why Am I Getting An Ora-01000: Maximum Open Cursors Exceeded Error, Even Though I Closed All Resultset, Statement, And Connection Objects?

This is an Oracle trouble. According to Oracle's documentation, dynamic cursors can stay open from run to run in a session and aren't closeable when a procedure closes. To work round this trouble, you could increase the variety of open cursors allowed in the database or you can reset the relationship pool (close and reopen database connections within the connection pool).

To reset the connection pool, you can untarget and retarget the relationship pool the usage of the Administration Console. You also can use the reset() approach thru the JMX API or the RESET_POOL command on the WebLogic Server command line interface.

Q3. How Do I Call Oracle Stored Procedures That Take No Parameters?

Here is what we use that works:

CallableStatement cstmt = conn.PrepareCall("Begin procName;

END;");

cstmt.Execute();

in which procName is the call of an Oracle saved process. This is standard Oracle SQL syntax that works with any Oracle DBMS.

You may use the subsequent syntax:

CallableStatement cstmt = conn.PrepareCall("name procName;");

cstmt.Execute();

This code, which conforms to the Java Extended SQL spec, will paintings with any DBMS, not simply Oracle.

Q4. What Is The No_acknowledge Acknowledge Mode Used For?

The NO_ACKNOWLEDGE renowned mode indicates that received messages do now not want to be in particular recounted which improves overall performance, however risks that messages are misplaced. This mode is supported for programs that don't require the first-class of carrier furnished by consultation renowned and that don't want to incur the associated overhead. V Messages sent to a NO_ACKNOWLEDGE session are right now deleted from the server. Messages acquired on this mode are not recovered and, as a result, messages may be misplaced and/or replica message may be delivered if an initial try and deliver a message fails.

Note: You need to keep away from using this mode in case your software can't cope with misplaced or reproduction messages. Duplicate messages may be despatched if an preliminary attempt to supply a message fails.

In addition, we do now not advise that this renowned mode be used with persistent messaging, as it implies a nice of service that may be too low for continual messaging to be beneficial.

Q5. How Do The Wls Jms 6.1 Server/vacation spot Message Maximum And Threshold Values Work?

The byte and message maximum values are quotas - no longer waft manage. Message quotas save you a WebLogic JMS server from filling up with messages and probable running out of memory, inflicting sudden results. When you attain your quota, JMS prevents further sends with a ResourceAllocationException (in preference to blocking off). You can set quotas on man or woman locations or on a server as a whole.

The thresholds also are now not flow manage - though they would be higher desirable to that utility than the quotas. The thresholds are definitely settings that after passed reason a message to be logged to the console to let you recognise which you are falling at the back of.

Note that the messages most setting on a connection manufacturing facility isn't a quota. This specifies the most numbers of superb messages that could exist after they were driven from the server however before an asynchronous client has seen them; it defaults to a price of 10.

Q6. When Should I Use Server Session Pools And Connection Consumers?

WebLogic JMS implements an optionally available JMS facility for defining a server-controlled pool of server sessions. This facility permits an application to technique messages concurrently. A ConnectionConsumer item uses a server consultation to technique received messages. If message site visitors is heavy, the connection customer can load each server consultation with a couple of messages to limit thread context switching. Multiple connection customers can share server periods in a server session pool.

Q7. Why Did My Jdbc Code Throw A Roll Back Sql Exception?

Your JDBC code can also throw the subsequent exception:

"The coordinator has rolled lower back the traction.

No further JDBC get right of entry to is allowed within this traction."

The WebLogic JTS JDBC driving force throws this exception whilst the current JDBC connection traction rolls again previous to or for the duration of the JDBC name. This exception suggests that the traction in which the JDBC connection became participating was rolled back at some point prior to or all through the JDBC name.

The rollback may also have befell in an earlier EJB invoke that changed into part of the traction, or the rollback might also have befell because the traction timed out. In both case, the traction will be rolled lower back, the relationship again to the pool and the database assets launched. In order to continue, the JTS JDBC connection must be closed and reopened in a brand new traction.

Q8. Why Do I Get "noclassdeffound"/"too Many Open Files"messages On Solaris?

When I am the use of WebLogic Server on Solaris and attempt to run my software, I get a "NoClassDefFound" blunders, despite the fact that the magnificence inflicting the error does exist and is inside the right listing. In fact, there are different instructions inside the same directory which can be getting loaded. I additionally get a "Too many open documents" errors.

We have visible this situation while the user account runs out of report descriptors. On Solaris, each consumer account has a sure constrained number of file descriptors. You can find out how many record descriptors you have got with the limit command in csh.

You can boom document descriptors when you have sufficient privileges with the ulimit command within the csh. Otherwise, ask your device administrator to boom the report descriptors available on your techniques.

Q9. What Type Of Object Is Returned By Resultset.Getobject()?

WebLogic jDriver for Oracle usually returns a Java object that preserves the precision of the statistics retrieved.

WebLogic jDriver for Oracle returns the following from the getObject() approach:

For columns of kinds NUMBER(n) and NUMBER(m,n): a Double is lower back if the defined precision of the column can be represented by means of a Double; in any other case BigDecimal is back.

For columns of kind NUMBER: Because there's no express precision, the Java type to return is determined based totally at the actual fee in each row, and this could range from row to row. An Integer is again if the value has a 0-valued fractional aspect and the price can be represented by way of an integer.

For example, 1.0000 might be an integer. A lengthy is lower back for a fee inclusive of 123456789123.000@If a price has a non-0 fractional thing, a Double is back if the precision of the value can be represented through a Double; otherwise a BigDecimal is lower back.

Q10. How Do I Restrict Access To Servlets And Jsps?

The Java Servlet API Specification v2.2 lets in you to declaratively restrict access to precise Servlets and JSPs the use of the Web Application Deployment descriptor. Section 13.3.2 of the specification has an example deployment descriptor that uses declarative protection.

Q11. What Happens If Acknowledge() Is Called Within A Traction?

As in line with the JMS specification, when you are in a traction, the acknowledgeMode is neglected. If well known() is known as within a traction, it's miles omitted.

Q12. What Is Error Ora-6502?

The default duration of a string bound to an OUTPUT parameter of a CallableStatement is 128 characters. If the cost you assign to the certain parameter exceeds that duration, you may get this mistake.

You can adjust the duration of the value of the bound parameter with the aid of passing an specific length with the dimensions argument to the CallableStatement.RegisterOutputParameter() method.

Q13. Does Weblogic Jms Support Clustering?

WebLogic JMS helps cluster-extensive, trparent access to locations from any server within the cluster. A machine administrator can set up cluster-huge, trparent access to destinations from any server within the cluster by way of configuring more than one connection factories and the use of objectives to assign them to WebLogic Servers. Each connection factory may be deployed on a couple of WebLogic Servers.

The application uses the Java Naming and Directory Interface (JNDI) to appearance up a connection manufacturing facility and create a connection to establish communication with a JMS server. Each JMS server handles requests for a hard and fast of locations. Requests for locations not handled through a JMS server are forwarded to an appropriate server.

You can configure a couple of JMS servers on the numerous nodes inside the cluster as long as you supply them special names. You can assign destinations to the diverse JMS servers.

One trouble to be aware of is the propagation delay in replicating entries in JNDI. If you've got an MDB deployed on one node but reference a destination on another node, the deployment might also fail with a javax.Naming.NamingException exception. The problem takes place because the server isn't always synced up to the JNDI from the far off server (JMS server) yet, so the JNDI research of destination as a part of MDB deployment will fail. One workaround is for every MDB to reference a local destination.

Another technique is set up the MDBs after the server boots (plus a postpone for JNDI propagation). To get around losing messages before the MDB is deployed, use durable subscribers. This problem is fixed for MDBs in WLS 6.1, in which the MDB might be deployed and reconnection could be retried till the vacation spot is to be had. 

Q14. Can The Messaging Bridge Handle Two-segment Or Global Tractions Between Separate Weblogic Server Domains Or Between Different Releases?

Yes, so long as the communication is among supply and target WebLogic domains that are both jogging release 6.1 SP3 or later, and the bridge is configured to use the Exactly-once pleasant of carrier.

Q15. How Do I Get A Thread Dump To Help Track Down A Problem?

Ways to get a thread unload:

Try running this from the command line (after going for walks the setEnv script in /bea/wlserver6.1/config/mydomain/):

java weblogic.Admin -url t3://localhost:7001 THREAD_DUMP

On Windows, from the console window, input Ctrl+Break.

On UNIX, sign the server using kill -@

Q16. How Do I Prevent Errors When Running T3dbping?

When you are testing your Oracle database connections below UNIX, you may run SQL*PLUS and might efficaciously ping the database using utils.Dbping. However, when you operate the multitier utils.T3dbping utility, you receive an ORA-12154 error message.

First, make sure that your ORACLE_HOME surroundings variable is effectively set to factor in your Oracle set up. This variable ought to be set within the surroundings where the WebLogic server is running.

In the C-shell issue the subsequent command:

$ setenv ORACLE_HOME path

where route is the route on your Oracle set up.

In the Bourne shell, issue the following commands:

$ ORACLE_HOME=direction

$ export ORACLE_HOME

where course is the route to your Oracle set up. When you ping your database the use of the two-tier utils.Dbping utility, the JDBC driver hundreds the database customer library and establishes the connection to the database. When you operate the multitier utils.T3dbping software, the WebLogic Server loads a -tier driver and uses it to set up a database connection. In both instances, the identical method is used to connect to the database. SQL*PLUS works as it would not require ORACLE_HOME to locate the purchaser libraries.

If you are still experiencing problems, try this:

Open a command shell.

Run the two-tier model of utils.Dbping in this shell.

Start WebLogic on this shell from the command line:

$ java -ms32m -mx32m weblogic.Server

Open a second command shell.

Run the utils.T3dbping in the second shell in opposition to the server running inside the first command shell.

Q17. What Is The Function Of T3 In Weblogic Server?

T3 affords a framework for WebLogic Server messages that support for improvements. These upgrades encompass abbreviations and features, including item substitute, that work inside the context of WebLogic Server clusters and HTTP and different product tunneling.

T3 predates Java Object Serialization and RMI, at the same time as intently tracking and leveraging these specifications. T3 is a superset of Java Object. Serialization or RMI; some thing you may do in Java Object Serialization and RMI may be executed over T3.

T3 is remitted between WebLogic Servers and between programmatic clients and a WebLogic Server cluster. HTTP and IIOP are non-compulsory protocols that may be used to talk among other strategies and WebLogic Server. It depends on what you need to do.

For example, while you want to communicate among

A browser and WebLogic Server-use HTTP

An ORB and WebLogic Server-IIOP.

Q18. Java-corba Integration: Rmi-iiop Or Java Idl?

It is vital to understand the difference among those  methods of integrating Java with CORBA.

RMI-IIOP is for Java programmers who need to application to the RMI interfaces however use IIOP because the underlying trport. RMI-IIOP presents interoperability with different CORBA items carried out in various languages, however handiest if all the faraway interfaces are at the start defined as Java RMI interfaces. It is of unique hobby to programmers using Enterprise JavaBe (EJBs), because the far flung item version for EJB is RMI-based totally.

Java IDL is for CORBA programmers who want to program in Java based totally on interfaces described in CORBA IDL. This is "commercial enterprise as traditional" CORBA programming, helping Java in precisely the same way as other languages like C++ or COBOL.

Q19. How Do I Debug Weblogic Server Using Visual Cafe four.1?

You can install VisualCafe Enterprise Edition four.1 and fix it to the server, pretty lots as it labored for 3.X.

The following are steps for debugging the usage of VC four.@You may additionally exchange the listing names as necessary:

Install it under D:VisualCafeEE. No unique alternatives are needed.

Install the license beneath C:Program FilesCommon FilesWebGain Shared.

Start ddservices via deciding on Start -> Programs -> WebGain Studio Professional ->Visual Cafe Enterprise Edition 4.1 -> Distributed Debugging Services -> Start DD Services (Java2 - 1.Three)

Start WebLogic Server using debugvm.Exe in preference to java.Exe.

Cd D:beawlserver6.1configmydomain

setEnv

edit startWebLogic.Cmd

change "%JAVA_HOME%binjava" -hotspot -ms64m -mx64m to visualcafeEEjdk13bindebugvm.Exe

Run startWebLogic. It prints out some debugging records.

Run VisualCafe - Start -> Programs -> WebGain Studio Professional -> Visual Cafe Enterprise Edition four.1 -> Visual Cafe Enterprise Edition 4.1

From the File menu, pick out Attach to Process. If the whole thing is running effectively, you should see your machine name.

Click the + signal to increase the tree and pick your going for walks WebLogic Server.

Q20. How Does Concurrency Work For Message-driven Be?

The way concurrency is carried out for Queues is through spawning one JMSSession in line with MDB instance within the pool. Since JMSSessions are processed in parallel via JMS, concurrency is obtained obviously this way and JMS takes care of handing over the message to, at maximum, one listener. If an MDB is deployed to multiple servers in a cluster, JMSSessions are created for every MDB example on every server and load balancing can be executed across them.

For Topics in WebLogic JMS 6.1, there may be one JMSSession per bean instance within the pool. Because of the way Topics work, the consultation, and for this reason every bean instance, gets a copy of every message posted on that Topic. (There become also a problem that brought about parallel processing no longer to work successfully. This has been fixed for WLS 6.0 Service Pack 1.)

Within a unmarried server, one subject matter client is used to bypass out messages to more than one threads to get the concurrency even as producing simplest a single reproduction of each message. You can configure more than one MDBs to concentrate at the same subject matter and every MDB will receive a copy of every message. When the usage of more than one servers, every server gets its very own client and consequently its personal reproduction of every message. It isn't presently possible to proportion a patron throughout multiple servers. If you need a message to be processed by precisely one MDB, use a queue.

One customer had an example wherein subject matter MDBs are wished wherein there can be multiple implementations of the MDBs listening at the equal subject matter. In different phrases, a couple of MDB with a special implementation can be subscribing to the same topic. The consumer has no advanced way of knowing how many one-of-a-kind varieties of MDBs may be listening on the equal topic, but it's miles possible for there to be multiple listener, therefore subjects, no longer queues. For every sort of MDB listening on the topic, the message is delivered precisely once (i.E., the message may be delivered exactly as soon as to an example in each named MDB pool listening on the subject).

Q21. How Do I Use A Startup Class To Initialize And Later Reference Jms Objects?

You can use a shutdown elegance that does some thing like the following:

JMSobject WLSobject = null;

strive

WLSobject = JMSStartUp.GetJMSobject();

WLSobject.JMSCleanup();

catch(Exception e)

 

Servlets can offer a pleasant option to offer each initialization and cleanup.

Q22. How Do I Connect To An Sql Server Instance That Is Running On A Machine With Multiple Instances Of Sql Server 2000?

Each instance of MS SQL Server need to be listening on a unique port. So, you could use the port quantity in the houses which you bypass to the getConnection() approach or, in case of connection swimming pools,

you could specify the port assets in the following residences:

server=machineName

port=instancePort

To discover the port number in which every MS SQL Server instance is going for walks, run the server network application (within the Microsoft SQL Server software organization), pick out the server instance, pick out TCP/IP, and click the houses button.

Q23. What Can I Do When I Get Java.Lang.Outofmemoryerror Because Producers Are Faster Than Consumers?

Quotas may be used to assist this situation. Your sender will then receive ResourceAllocationExceptions and the server will stay up. WLS 6.X does not assist paging of messages out of reminiscence.

As of WLS 6.1 SP02 or later, you may use the Message Paging characteristic, which could free up precious virtual reminiscence for the duration of height message load periods by way of swapping out messages from virtual reminiscence to persistent storage whilst message hundreds attain a particular threshold.

Q24. Can I Enable Requests To A Jdbc Connection Pool For A Database Connection To Wait Until A Connection Is Available?

No, there may be no way to permit a request to watch for a pool connection, and from the device point of view there must no longer be. Each requests that waits for a connection ties up one of the constant range of execute threads inside the server, that could in any other case be running some other server challenge. Too many waiting requests may want to tie up all of the execute threads and freeze the server.

Q25. What Are Pending Messages In The Console?

Pending me the message might have been:

sent in a traction however now not dedicated.

Acquired and now not recounted.

Received and not committed.

Difficulty to a redelivery delay (as of WebLogic Server 6.1).

Difficulty to a shipping time (as of WebLogic Server 6.1).

A rolled back message remains pending until the traction in reality rolls lower back. Rolling it returned a couple of instances does not purpose double counting, nor does an exception that set a traction as rollbackOnly followed via an actual rollback.

Current implies messages that aren't pending.

Total implies total since server ultimate began. The byte counts only remember the payload of messages which incorporates the houses and the body but now not the header.

Q26. Are There C/c++ Interfaces To Wls Jms?

No, this is not supported:

Write your personal interfaces using JNI.

Setup a Servlet that your C/C++ patron calls to generate a JMS message. You have to spawn multiple threads in C++ and use multiple posts to skip messages via http.

Q27. Can An Mdb Be A Message Producer Or Both A Producer And Consumer?

Yes. You haven't any JMS context in the MDB so that you will need to set up a connection, consultation and producer your self. One alternative is to do that every time you come into the onMessage ordinary for the MDB. This is enough if the message rate is noticeably low. The 2nd option is to set up the necessary objects in ejbActivate().

Note that the items aren't serializable in order that they cannot be passivated for a stateful session bean or an entity bean. When the EJB deactivates, you want to close the associated objects. The third option is that you could build up a JMS connection/sender consultation pool within a startup elegance entire together with your personal synchronization and blocking off to get a connection.

Q28. Which Types Of Jdbc Databases Does Weblogic Jms Support?

The JMS database may be any database that is accessible thru a JDBC driver.

WebLogic helps and affords JDBC drivers for the following databases:

Cloudscape

Informix

Microsoft SQL (MSSQL) Server (Versions 6.Five and 7)

Oracle (Version 8.1.6)

Sybase (Version 12)

Q29. Can I Use A Native Two-tier Driver For A Browser Applet?

No. Within an unsigned applet, you cannot load local libraries over the wire, get admission to the local document gadget, or connect to any host besides the host from which you loaded the applet. The applet safety supervisor enforces these restrictions on applets as safety towards applets being able to do unsavory matters to unsuspecting users.

If you are attempting to use jDriver for Oracle from an applet, then you are violating the first restriction. Your applet will fail while it tries to load the native (non-Java layer) library that permits jDriver for Oracle to make calls into the non-Java Oracle customer libraries. If you observe the exception this is generated, you will see that your applet fails in java.Lang.System.LoadLibrary, because the security supervisor determined which you had been attempting to load a local library and halted the applet.

You can, however, use the WebLogic JTS or Pool driving force for JDBC connectivity in applets. When you operate this type of WebLogic multitier JDBC drivers, you want one copy of WebLogic jDriver for Oracle (or some other -tier JDBC motive force) for the connection between the WebLogic Server and the DBMS.

Q30. Why Do I Get An Error While Trying To Retrieve The Text For Ora-12705?

This errors happens if you have not set the ORACLE_HOME surroundings variable well - a common mistake. In order to use WebLogic jDriver for Oracle, the Oracle customer software program wishes to be mounted and ORACLE_HOME should be set.

You can also see this error message if you attempt to use WebLogic jDriver for Oracle's internationalization talents with a language/codeset mixture that isn't mounted to your machine. If you get the ORA-12705 errors with the right blunders textual content, then either you have set NLS_LANG improperly, or you do not have the right codesets set up to your device.

Q31. How Should I Use Sorted Queues?

Destination keys are used to define the type order for a selected destination. Destination keys can be message header or property fields. For a listing of valid message header and belongings fields, talk over with the Programming WebLogic JMS.

Queues may be looked after in ascending or descending order based on the vacation spot key. A destination is considered to be first-in-first-out if a destination secret is defined as ascending for the JMSMessageID message header field, and last-in-first-out if defined as descending. The key described for the JMSMessageID header subject, if specified, ought to be the remaining key described inside the listing of keys.

You can define multiple destination keys to sort a vacation spot.

Q32. How Can I Avoid Resourceexceptions When Sending More Requests For Database Connections From The Pool Than Are Currently Available?

The fundamental hassle is too few resources (database connections within the connection pool) for the paintings load. The correct response is to boom the most number of connections inside the connection pool. Optimally designed programs simplest require the server to have one pool connection per execute thread.

The proper application reaction to a aid exception isn't to retry the request in a good loop, which might tie up execute threads on the server.

You ought to layout your software to gracefully fail if no connections are available. Try to make certain which you get the connection as overdue as possible on your application code and go back them to the pool as early as viable so you do not see as many NoResource exceptions. It is higher to have the connection as a method level variable and near the relationship in a sooner or later block as inside the following instance:

strive

...

 Trap(Exception handleEx) 

...

 Sooner or later 

attempt conn.Close();

catch (Exception ignore) // continually go back the connection to pool

 

Q33. Is It Better To Have More Or Fewer Sessions For A Given Number Of Subscribers?

Using N sessions for N subscribers offers you concurrency up to N simultaneous threads of execution supplied you've got as many threads to work with. Each Session gets its own thread so long as there are sufficient threads to be had. Otherwise, the periods serially reuse the available threads.

One session for N subscribers serializes all subscribers via that one session. If the weight is heavy they may now not be capable of keep up with out the more threads.

If you are the usage of CLIENT_ACKNOWLEDGE, N classes offers you N separate message streams that may be for my part recovered. Having one consultation crosses the streams providing you with much less control.

Q34. How Do I Use A Temporary Destination?

You have to create a template on every JMSServer where you need to be able to create brief locations. You can specify multiple JMSServer entries to aid Temporary Template and the device will load stability amongst those JMS servers to setup the brief vacation spot.

The JMSServer is described something like:

 After the template name, you may set any queue/topic attribute you want within the template (no longer inclusive of a JNDI call or subject matter multicast settings). The template is at the outer most stage; this is, it need to no longer be nested in your .

Temporary locations can most effective be ate up via the developing connection. Using topics, you create your transient topic and join that brief topic. If you want a person to submit to that brief topic, you need to tell that a person what your topic is. You can ship them a message and include your transient topic inside the JMSReplyTo area. The creator of the TemporaryTopic and the subscriber should be one inside the same.

Import javax.Jms.TopicSession;

TemporaryTopic myTopic = mySession.CreateTemporaryTopic();

TopicSubscriber = mySession.CreateSubscriber(myTopic);

Temporary topics do now not get names and can not be subscribed to through other connections. When you create a temporary subject matter, the JMS provider returns a javax.Jms.Topic. You then want to advertise that topic to other parties (individuals who need to publish to the topic), putting it for your JMSReplyTo field so that they can reply. In wellknown, nobody else can enroll in the topic. You promote it the subject any way you want. Topics are serializable (or, in our case, externalizable), which lets in you to bypass them around in RMI calls, through a record, binding it to a call in JNDI, and so forth. In quick, create the subject at the subscriber side and put it up for sale so that others can post. You can get multiple subscribers on the equal connection and get concurrent processing the use of more than one periods.

Q35. How Does Weblogic Support Corba And Client Communication Via Iiop?

"CORBA" support me many things to many people. It frequently me in reality IIOP /ORB aid and no longer an awful lot on CORBA offerings. WebLogic helps CORBA in multiple approaches.

First, Java customers can tunnel through a CORBA surroundings to WebLogic Server. We call this "IIOP tunneling," and it's far supposed to be used with applets coming through an IIOP firewall, which includes the IONA Wonderwall product. This is a Java-to-Java model using over an IIOP communications framework.

WebLogic RMI over IIOP provides RMI offerings for many clients (along with CORBA clients) over IIOP.

WebLogic Enterprise Connectivity enables you to create IIOP connection pools to a BEA WebLogic Enterprise System, permitting you to execute WebLogic Enterprise CORBA items from WebLogic Server servlets and Enterprise JavaBe.

Q36. Which Xml Parser Comes With Weblogic Server 6.1?

We package deal a parser, based totally on Apache's Xerces 1.3.1 parser, in WebLogic Server 6.@In addition, we consist of a WebLogic proprietary high-performance non-validating parser that you can use for small to medium sized XML documents. The WebLogic XML Registry permits you to configure the parser you need to apply for specific document sorts.

Q37. How Do I Put A Message Back On The Queue For Processing?

The following are several approaches:

Use a tracted consultation, then rollback the consultation so the message will move returned to the queue.

Use Session.CLIENT_ACKNOWLEDGE while growing a consultation, then recover the consultation so the message will move again to the queue.

Use a JTA traction, then rollback the traction so the message will cross returned to the queue.

Q38. Can The Messaging Bridge Forward Durable Subscription Messages Between Separate Weblogic Server 6.1 And Release 7.0 Or Later Domains?

Yes, so long as the WebLogic 7.Zero area is the usage of Service Pack 1 or later. To enable long lasting messages throughout the messaging bridge using the Administration Console, pick the Durability Enabled characteristic on the Messaging Bridge -> Configuration -> General tab.

Q39. Why Is There No Polymorphic-type Response From A Create() Or Find() Method?

The EJB Specification prohibits this conduct, and the weblogic.Ejbc compiler exams for this conduct and prohibits any polymorphic form of response from a create() or discover() method.

The reason the create() and discover() strategies aren't polymorphic is much like the cause constructors are not polymorphic in Java. The derived instructions commonly do no longer know or can not initialize the bottom elegance well.

Q40. Can I Configure The Messaging Bridge To Automatically Downgrade The Quality Of Service If The Exactly-once Service Is Not Available On Either The Source Or Target Bridge Destination?

Yes, just make sure to select the QOS Degradation Allowed take a look at field at the Messaging Bridge -> Configuration -> General management console page.

Q41. What Is The Standard Way To Create Threads, Do Initialization, Etc. Within The Application Server?

Threads must commonly now not be created by means of the person immediately is because things may not paintings efficaciously. User-created threads do no longer have a number of the thread-local variables pre-set by way of WebLogic while it creates it's very own execute threads, the associated traction context, or the environment inclusive of the proper class loader.

The WebLogic-specific way of doing this is with a startup class or the usage of the WebLogic Time Services. The portable manner to do that is to outline a load-on-startup servlet, doing the initialization in the init() approach and the cleanup inside the smash() approach.

The servlet itself does nothing. This approach also lets in for undeploy/redeploy of the software without restarting the server, such as proper cleanup/initialization every time. It also vendors greater dynamic control of the structured instructions with out restarting the server.

Q42. How Do I Increase Weblogic Server Memory?

Increase the allocation of Java heap reminiscence for WebLogic Server. (Set the minimum and the maximum to the same length.) Start WebLogic Server with the -ms32m option to growth the allocation, as in this case:

$ java ... -ms32m -mx32m ...

This allocates 32 megabytes of Java heap memory to WebLogic Server, which improves overall performance and allows WebLogic Server to deal with more simultaneous connections. You can increase this cost if vital.

Q43. Why Do I Get An Exception When Trying To Find A Connection Factory?

The exception is commonly some thing like java.Io.InvalidClassException or java.Lang.NoClassDefFoundError.

Make positive weblogic.Jar is within the CLASSPATH of the client. Also ensure you have the suitable Java run-time jar documents covered (i.E., you may want rt.Jar).

Q44. How Do I Bind String Values In A Preparedstatement?

Suppose you are trying to tget the PreparedStatement class to bind Strings in a assertion. The setString() approach would not seem to work.

Here is how you have installation the PreparedStatement:

String pstmt = "pick out n_name from n_table in which n_name LIKE

'?%'";

PreparedStatement ps = conn.PrepareStatement(pstmt);

playstation .SetString(1, "SMIT");

ResultSet rs = playstation .ExecuteQuery();

The preceding code does now not paintings because the complete price wishes to be laid out in a String (with out using embedded rates) and then bound to an unquoted query-mark (?).

Here is the corrected code:

String matchvalue = "smit%";

String pstmt = "choose n_name from n_table where n_name LIKE ?";

PreparedStatement playstation  = conn.PrepareStatement(pstmt);

ps.SetString(1, matchvalue);

ResultSet rs = ps.ExecuteQuery();

Q45. How Do Stubs Work In A Weblogic Server Cluster?

Clients that hook up with a WebLogic Server cluster and look up a clustered object gain a duplicate-conscious stub for the item. This stub contains the list of available server instances that host implementations of the object. The stub additionally includes the load balancing common sense for distributing the load amongst its host servers.

Q46. How Do I Configure Jms Security?

The accurate way to installation security for JMS is to go to the console, select ACLs inside the tree view, then create a few get right of entry to manipulate lists.

Set the ACL name which should be weblogic.Jms.Queue.QUEUENAME or weblogic.Jms.Topic.TOPICNAME.

Select Create.

Enter the New Permission of ship or get hold of.

Select Create.

Enter a comma separated listing of customers or agencies.

Select Grant Permission.

Select "saved to the area implementation" to store your modifications.

Select Yes.

This will update the fileRealm.Homes document with strains that appear to be the following:

acl.Send.Weblogic.Jms.Queue.TestQueue1=user1

acl.Receive.Weblogic.Jms.Queue.TestQueue1=user1

If you don't have an ACL for a queue or subject matter, security is extensive open.There also are ACL's for getting access to the JNDI context; the JNDI context is a demand for to start with accessing JMS. 

Q47. Must Ejbs Be Homogeneously Deployed Across A Cluster? Why?

Yes. Beginning with WebLogic Server model 6.0, EJBs have to be homogeneously deployed throughout a cluster for the following motives:

To preserve clustering EJBs easy

To avoid pass server calls which leads to extra efficiency. If EJBs aren't deployed on all servers, cross server calls are more likely.

To make certain that each EJB is to be had locally

To make sure that all classes are loaded in an undeployable manner

Every server should have get entry to to each EJB's classes in order that it can be sure into the local JNDI tree. If simplest a subset of the servers deploys the bean, the alternative servers will have to load the bean's instructions in their respective gadget classpaths which makes it impossible to undeploy the be.

Q48. What Is Bea Weblogic?

BEA WebLogic is a J2EE software server and additionally an HTTP web server via BEA Systems of San Jose, California, for Unix, Linux, Microsoft Windows, and different structures. WebLogic helps Oracle, DB2, Microsoft SQL Server, and different JDBC-compliant databases. WebLogic Server helps WS-Security and is compliant with J2EE 1.Three.

BEA WebLogic Server is part of the BEA WebLogic Platform. The other elements of WebLogic Platform are:

Portal, which incorporates Commerce Server and Personalization Server (which is constructed on a BEA-produced Rete regulations engine),

WebLogic Integration,

WebLogic Workshop, an IDE for Java, and

JRockit, a JVM for Intel CPUs.

WebLogic Server consists of .NET interoperability and supports the subsequent local integration talents:

Native employer-grade JMS messaging

J2EE Connector Architecture

WebLogic/Tuxedo Connector

COM+ Connectivity

CORBA connectivity

IBM WebSphere MQ connectivity

BEA WebLogic Server Process Edition also consists of Business Process Management and Data Mapping functionality. WebLogic helps safety policies controlled by using Security Administrators.

The BEA WebLogic Server Security Model consists of:

Separate software commercial enterprise logic from security code

Complete scope of safety coverage for all J2EE and non-J2EE additives

Q49. How Is Security Handled In The Weblogic J2ee Connector Architecture?

Due to the fact that the contemporary configuration and packaging necessities for useful resource adapters in WebLogic Server require the hand-enhancing of the weblogic-ra.Xml file, any new passwords exact within the security-important-map entries are executed in clean-textual content.

BEA is familiar with the significance of defensive safety passwords. Hence, we offer a Converter Tool that permits for the encryption of all passwords gift within the weblogic-ra.Xml file. The Converter Tool is sent in the fashionable weblogic.Jar document.