Srinivas Ramgopal

Hi all,

I have 3 different applications/ears deployed on the same weblogic application server instance.
I intend to enable logging including databse logging for all thesee applications and thus have the required third party jars in the weblogic system classpath.
But I am getting classnotfoundexception for a particular class during the application server startup.

I read the weblogic classloading mechism doc. But I still have few general questions related to jars in system classpath and the wl classloading mechanism and related known issues:

1a) When and why does versioning issues occur in wl.

1b) Is the classcastexception related to that? If so, how to fix it?

2) What are the common issues faced during the wl startup specific to third party jars in system classpath.

3) How to debug the classloading issues in wl.

4)Does adding entries to startweblogic.cmd instead of adding jars to the system classpath, avoid classloading issues? If so, how to do it.

5)Is there anything similar to Contextual Repository Selector in weblogic to load third party jars other than log4j.jar?

6) Also is there a better strategy to implement inorder to make use of common third party jars accross different EARs deployed on the same application server instance?


Any pointers to articles/tools/code snippets are highly appreciated.

Your help in this regard is highly appreciated.

Thanks in advance for your valuable time and interest.

Hi all,

I have a mavenized J2EE application in weblogic application and the database being Oracle.
I am having a single EAR deployed to the application server instance. I am trying to log messages to database using jdbcplus.jdbcappender.java from jdbcappender.jar from http://www.dankomannhaupt.de/projects/index.html.
Thus I put the jdbcappender.jar, log4j.jar, wllog4j.jar, classes12.jar in the weblogic system classpath.
But I get classcastexception while starting the weblogic application server as shown below. (Note: log4j.jar also has a class of same name but in different package (org.apache.log4j.jdbc.jdbcappender). Also I made sure that the Ear �s APP-INF/lib does not have both log4j.jar and jdbcappender.jar to avoid the classloader issues if any).

Your input/pointers are highly appreciated. Thanks in advance for your time.


log4j:ERROR Could not create an Appender. Reported error follows. java.lang.ClassCastException: jdbcplus.JDBCAppender log4j:ERROR Could not create an Appender. Reported error follows. java.lang.ClassCastException: jdbcplus.JDBCAppender at org.apache.log4j.xml.DOMConfigurator.parseAppender(DOMConfigurator.java:165) at org.apache.log4j.xml.DOMConfigurator.findAppenderByName(DOMConfigurator.java:140) at org.apache.log4j.xml.DOMConfigurator.findAppenderByReference(DOMConfigurator.java:153) at org.apache.log4j.xml.DOMConfigurator.parseChildrenOfLoggerElement(DOMConfigurator.java:415) at org.apache.log4j.xml.DOMConfigurator.parseCategory(DOMConfigurator.java:335) at org.apache.log4j.xml.DOMConfigurator.parse(DOMConfigurator.java:781) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:666) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:616) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:602) at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:460) at org.apache.log4j.LogManager.<clinit>(LogManager.java:113) at org.apache.log4j.Logger.getLogger(Logger.java:85) at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:229) at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:65) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:494) at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529) at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235) at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:370) at org.apache.beehive.netui.util.logging.Logger.getInstance(Logger.java:44) at org.apache.beehive.netui.pageflow.PageFlowUtils.<clinit>(PageFlowUtils.java:76) at com.bea.netuix.servlets.manager.AppDescriptor.loadDescriptor(AppDescriptor.java:1076) at com.bea.netuix.servlets.manager.SingleFileServlet.reinitInternal(SingleFileServlet.java:121) at com.bea.netuix.servlets.manager.SingleFileServlet.initInternal(SingleFileServlet.java:86) at com.bea.netuix.servlets.manager.SingleFileServlet.access$100(SingleFileServlet.java:52) at com.bea.netuix.servlets.manager.SingleFileServlet$ServletLifecycleListenerImpl.init(SingleFileServlet.java:287) at com.bea.netuix.util.ServletLifecycleListener.initOrReinitInternal(ServletLifecycleListener.java:131) at com.bea.netuix.util.ServletLifecycleService.addServletLifecycleListener(ServletLifecycleService.java:251) at com.bea.netuix.util.ServletLifecycleService.addServletLifecycleListener(ServletLifecycleService.java:182) at com.bea.netuix.servlets.manager.SingleFileServlet.init(SingleFileServlet.java:79) at javax.servlet.GenericServlet.init(GenericServlet.java:256) at weblogic.servlet.AsyncInitServlet.initDelegate(AsyncInitServlet.java:94) at weblogic.servlet.internal.WebAppServletContext$AsyncInitRequest.run(WebAppServletContext.java:1651) at weblogic.work.ServerWorkManagerImpl$WorkAdapterImpl.run(ServerWorkManagerImpl.java:518) at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209) at weblogic.work.ExecuteThread.run(ExecuteThread.java:181) log4j:ERROR Could not parse input source [org.xml.sax.InputSource@1ac5211]. java.lang.NullPointerException at java.util.Hashtable.put(Hashtable.java:396) at org.apache.log4j.xml.DOMConfigurator.findAppenderByName(DOMConfigurator.java:141) at org.apache.log4j.xml.DOMConfigurator.findAppenderByReference(DOMConfigurator.java:153) at org.apache.log4j.xml.DOMConfigurator.parseChildrenOfLoggerElement(DOMConfigurator.java:415) at org.apache.log4j.xml.DOMConfigurator.parseCategory(DOMConfigurator.java:335) at org.apache.log4j.xml.DOMConfigurator.parse(DOMConfigurator.java:781) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:666) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:616) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:602) at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:460) at org.apache.log4j.LogManager.<clinit>(LogManager.java:113) at org.apache.log4j.Logger.getLogger(Logger.java:85) at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:229) at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:65) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:494) at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529) at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235) at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:370) at org.apache.beehive.netui.util.logging.Logger.getInstance(Logger.java:44) at org.apache.beehive.netui.pageflow.PageFlowUtils.<clinit>(PageFlowUtils.java:76) at com.bea.netuix.servlets.manager.AppDescriptor.loadDescriptor(AppDescriptor.java:1076) at com.bea.netuix.servlets.manager.SingleFileServlet.reinitInternal(SingleFileServlet.java:121) at com.bea.netuix.servlets.manager.SingleFileServlet.initInternal(SingleFileServlet.java:86) at com.bea.netuix.servlets.manager.SingleFileServlet.access$100(SingleFileServlet.java:52) at com.bea.netuix.servlets.manager.SingleFileServlet$ServletLifecycleListenerImpl.init(SingleFileServlet.java:287) at com.bea.netuix.util.ServletLifecycleListener.initOrReinitInternal(ServletLifecycleListener.java:131) at com.bea.netuix.util.ServletLifecycleService.addServletLifecycleListener(ServletLifecycleService.java:251) at com.bea.netuix.util.ServletLifecycleService.addServletLifecycleListener(ServletLifecycleService.java:182) at com.bea.netuix.servlets.manager.SingleFileServlet.init(SingleFileServlet.java:79) at javax.servlet.GenericServlet.init(GenericServlet.java:256) at weblogic.servlet.AsyncInitServlet.initDelegate(AsyncInitServlet.java:94) at weblogic.servlet.internal.WebAppServletContext$AsyncInitRequest.run(WebAppServletContext.java:1651) at weblogic.work.ServerWorkManagerImpl$WorkAdapterImpl.run(ServerWorkManagerImpl.java:518) at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209) at weblogic.work.ExecuteThread.run(ExecuteThread.java:181) log4j:WARN No appenders could be found for logger (org.apache.beehive.netui.pageflow.internal.AdapterManager). log4j:WARN Please initialize the log4j system properly.

Hi all,

Our SOA application currently under development has two new tasks -
1) Process about seven thousand real time records per day using JMS.
2) Migrate about 500 million records from a different system through JMS.

As of now, we are thinking of using persistent queues but not sure about many other details as we just came up with first pass architecture.

Thus your valuable input about any good books/articles related to industry standards of messaging patterns and performance that would be helpful in our current efforts is highly appreciated.

Thanks in advance.

Regards.

Hi all,

I am trying to refactor a class that has lot of redundant methods.

The original purpose of the class is to create object of class A and set its attributes; All the attributes have static values except one attribute; this attribute represents different types of classes/objects example -->(Order or Shipment) based on user request. These different classes are created by different factories (OrderObjectFactory or ShipmentObjectFactory) that DO NOT need refactoring.

The reasons for refactoring as follows:
1) To remove redundancy. Currently the class has grown over time and has methods that have duplicate code for each user request of creating an object having Order/Shipment/XX/YY/ZZ object as an attibute.

2) A need to create more types of classes (like wkorder/invoice) will grow in the future. Thus need to accomodate this change.

I started exploring the creational patterns like Factory Method and Abstract factory patterns.
So far I tried to separate the changing part from the unchanging part in my class. Changing part being --> calling Order or Shipment object factory to create Order/Shipment objects and setting their attibutes.

For the changing part, should I use abstract factory pattern or factory method patten???
As far as I understand the abstract factory pattern defintion, it might not be useful in my case as this pattern's intent is to create a family of objects (In my case, I set only one attribute of class A with a fully populated Order/Shipment object based on user request).

My questions are:
1) Is abstract factory pattern suitable for the above scenario OR are there any suitable creational patterns?

2) Is Sping context based injection of the Order/ShipmentobjectFactory OR setting the attributes of the Order/Shipment objects recommended along with/without the creational patterns usage?

I would appreciate code/skeleton snippets for any of your recommendations.

Thanks in advance for your valuable time and input.

Best regards.

Hi all,

I have few questions about corp to corp billing rate for J2EE devlopers with 7-11 years experience.
The experience is mainly with 2 life cycle J2EE projects (large scale mission critical projects based on RUP, agile devlopement and worked right from Inception stage and worked in architect and developer teams).

For this type of experience,
1)what is the corp to corp rate range expected.

2)How much does it vary on average in terms of geographical locations in US.

3)What is the market trend of hourly rate increase each year? Is there a $5-$10 increase per year.
4) In case a company gives a choice between permanent salary position + benifits and corp to corp.
4a)How to negotiate corp to corp rate? --->Would the corp to corp rate be salary figure + offered benifits value + 2-3 weeks vacation worth of amount + health insurance payments?
4b) Also Should the first pass negotiatation of corp to corp start with $5 more than expected?


Your valuable input is highly appreciated.


Thanks in advance for your valuable time and interest

Hi all,

I want to create a jar of 60 jars that need to be used in the classpath and I used the following:

jar cvfm new.jar manifest.txt -C lib/ .

The manifest file content looks like below but has reference to 60 jars:

Class-Path: MyUtils.jar xx.jar yy.jar


The jar command fails saying 'line too long'

So my questions are:

1) How to avoid this error since I also tried having only 3 jars per line in the manifest file.

2) Also is there a better way to include a jar/zip of jars in a classpath.

3) Is there a javav utlity that creates a jar of jars and updating the manifest file?

Thanks in advance for your time and effort.

Hi all,

I wrote a java program to load a .class file from a jar file.
The .class file resides in a different namespace than that of this java program.

I am using Class.forName(fully qualified class name) which is throwing a java.lang.ClassNotFoundException exception during runtime.

Code is as follows:

JarFile jarFile = new JarFile("../lib/xyz.jar"); JarEntry entry = jarFile.getJarEntry("zz/xx/Foo.class"); InputStream input = jarFile.getInputStream(entry); InputStreamReader isr = new InputStreamReader(input); BufferedReader reader = new BufferedReader(isr); String className = entry.getName(); Class clazz= Class.forName("className"); clazz.newInstance();

Any input is highly appreciated.

Thanks in advance.

Hi all,

I have just started working on performance monitoring and load testing of a J2EE distributed application running on weblogic application server. The application has web services and local ejbs. The application runs on Linux and HP-UX enviornments.

I am unable to decide as which of the following are useful in above case:

Jps
Jstat
Jmap
Hprof
Hat
Jstack
Jconsole.

Also please let me know if a combination of one or more is to used.

Also any pointers to useful articles/books are highly appreciated.

Thanks in advance.

Hi all,

I am working on performance tuning and load testing task on weblogic 9.x/10 application server.


I see a lot of books in amazon.com but not sure which is good specific to distributed transactions, threading, caching etc.
Thus I would like to take your input/recommendation for any good related books and articles.

Your input is highly appreciated.


Thanks in advance.
[ May 31, 2007: Message edited by: Srinivas Ramgopal ]

Hi all,

I am working a J2EE application running on weblogic 9.x/10 application server.

I tested 2 scenarios:
1) A Webservice that calls a local stateless session bean via t3 protocol.

2) A webservice that calls a pojo.

I observed that webservice calling ejb is faster. Did anyone find the same observation? If so, is it because the t3 protocol is more optmized.

Your input is highly appreciated.


Thanks in advance.

Hi all,

There are tons of java classes in my current project that have zero documentation at class and method level.
I tried using eclipse 3.2's tool for generating java docs for these classes but was not helpful in terms of knowing the PURPOSE of the class/method.

It is being a tedious task to hand write the class/method level documentation/purpose. Thus wondering if there is any open source utility tool that intutively auto generates the java doc complaint documentation blocks within the class ALONG with the purpose of the method/class by understanding the code??

Example: I want the tool to generate the following block for a method as follows:

[B]/** * This method handles the CRUD requests. * @param XXX * @return YYY * @throws ZZZ * @see xyz.x.y.z */[/B] public void xx();

Any help is HIGHLY appreciated.

Thanks a ton in advance.
[ March 03, 2007: Message edited by: Srinivas Ramgopal ]

Hi all,

I am new to weblogic and recently installed weblogic 9.x.

I have couple of questions:
1) How does the memory caching work in weblogic? - any data stored in static hashmap (declared at the class level) is not being refershed inspite of a fresh deployment of the application.
The work around was that the weblogic server needs to be restarted to pick up the new values from the static data structure.
Is there any setting to refresh data and avoid the server restart?

2) Whenever a database is shutdown, the weblogic datasources become stale.
Is there a setting that automatically reactivates the datasources and the connection pool in weblogic without any manual intervention?


Thanks in advance for your time and interest.

Thank you for the recommended books.

Y'day, I saw a video clip of Kent Beck about 'Ease at work' which was highly thought provoking and self analysing for me.

http://video.google.com/videoplay?docid=7830246530742207581

Best regards.

Originally posted by Ilja Preuss:


Which books did you read? I'm always searching for new reading fodder...

I read mostly John C. Maxwell's books. I still have to read 'Fearless Change' recommended by you long time ago.

Do you mind recommending any more good books that you liked!?

Originally posted by Ilja Preuss:


I'm not sure I'm getting your point here. Care to elaborate?

First of all, I am not sure what changes a coach can bring in general, thus please excuse me for my ignorance.

What I noticed in teams in so far is that, each developer has his/her own personal style of working -->

A. Some team members do not plan anything but would never miss the deadlines.
B. Some team members are more self organized, have more sense of urgency, goal oriented and try to be productive atleast 7 hours a day. They always try to finish things early rather than dragging the pending work till the deadline.
C. Some team members are extroverts and some are introverts.

I heard frustrations especially when developers, each from A and B are paired together.

Though their frustrations that one is fast or one is slow are correct from their perspective, from a third person's observation there seem not to be a problem in either case since both types still meet the deadlines!

So will a coach be able to solve these kind of frustrations and get a balanced improvement in motivation and self organization in the team members?
To me, how much ever the coach tries, it all depends on the team members effort to motivate themselves for a new change and for sure it takes time!?

Your thoughts are highly appreciated.

Thanks in advance for your valuable input and time.

Originally posted by Frank Carver:
You might find this article interesting.[/QB]

Thank you! I will read it.

Hi

Sorry for the delayed response.

I did listen to the interesting and thought provoking 'Arlo Belshee's interview on promiscuous pairing from Agile 2005'.

That lead to few more questions in general.

From my experience as consultant in different companies/teams, I found that no two teams/projects are alike.
Especially, the energy in team is tied to the nature of the job. If the project is not that complicated, naturally team members are mostly on laid back side. Especially in such projects, I do not see much benefit of introducing pair programming concept, as it leads to initial chaos and lot of adjustment especially when rotating pairs. In other words, this demands lot of change in an indiviudal's attitude itself(especially if that person had been working in a laid back work atmosphere for a lot of years).

In such team enviornments, why not follow all prinicples of XP EXCEPT Pair Programming; Instead of pair programming, why not have extensive code reviews now and then during each iteration???

Also, I have been reading books about motivating teams to be more self organized etc.
But in real world, each team is made of different and sometimes difficult attitudes and different work styles which makes it real difficult to bring in a desired amount of change.
I really wonder at times, if bringing in a coach ALWAYS makes a big difference especially when the management is willing to see the changes only in a given period of time, since a coach is usually expensive???

Your thoughts are highly appreciated.


Thanks in advance for your valuable time and interest.