Rahul Gupta

Hello,

Facing a little problem :roll: . I have an application hosted on Websphere 5.x. My application generates Java Heap Dumps and Java Core dumps though I haven't configured it explicitly anywhere in any script or through the Admin Console.

I found from IBM site that the environment variable IBM_HEAPDUMP = true will generate heap dumps explicitly. I can try to stop by setting IBM_HEAPDUMP = false.

However I don't know whether the above method is right or not. Further more why is the application generating these dumps without any prior configuration is still un-answered.

The application doesn't through any OutOfMemory Exception. Hence the possibility of these dumps being created due to this exception can be ruled out.

Can anybody who has faced similar problem throw some light on it

Hi,
I have configured Tomcat to connect to Oracle Database. However it gives the following exception.
org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null', cause:
java.sql.SQLException: No suitable driver
The server.xml file is as follows:
<?xml version='1.0' encoding='utf-8'?> <Server> <Listener className="org.apache.catalina.mbeans.ServerLifecycleListener"/> <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"/> <GlobalNamingResources> <Environment name="simpleValue" type="java.lang.Integer" value="30"/> <Resource auth="Container" description="User database that can be updated and saved" name="UserDatabase" type="org.apache.catalina.UserDatabase"/> <Resource auth="Container" name="jdbc/OracleAdmin" type="javax.sql.DataSource"/> <ResourceParams name="UserDatabase"> <parameter> <name>factory</name> <value>org.apache.catalina.users.MemoryUserDatabaseFactory</value> </parameter> <parameter> <name>pathname</name> <value>conf/tomcat-users.xml</value> </parameter> </ResourceParams> <ResourceParams name="jdbc/OracleAdmin"> <parameter> <name>validationQuery</name> <value>select * from acc_user</value> </parameter> <parameter> <name>url</name> <value>jdbc:oracle:thin:@B3-3F094-8B1Q:1521:UBS</value> </parameter> <parameter> <name>password</name> <value>aw_dbo</value> </parameter> <parameter> <name>maxActive</name> <value>4</value> </parameter> <parameter> <name>maxWait</name> <value>5000</value> </parameter> <parameter> <name>driverClassName</name> <value>oracle.jdbc.driver.OracleDriver</value> </parameter> <parameter> <name>username</name> <value>aw_dbo</value> </parameter> <parameter> <name>maxIdle</name> <value>2</value> </parameter> </ResourceParams> </GlobalNamingResources> <Service name="Catalina"> <Connector acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" port="8080" redirectPort="8443"> </Connector> <Connector port="8009" protocol="AJP/1.3" protocolHandlerClassName="org.apache.jk.server.JkCoyoteHandler" redirectPort="8443"> </Connector> <Engine defaultHost="localhost" name="Catalina"> <Host appBase="webapps" name="localhost"> <Logger className="org.apache.catalina.logger.FileLogger" prefix="localhost_log." suffix=".txt" timestamp="true"/> </Host> <Logger className="org.apache.catalina.logger.FileLogger" prefix="catalina_log." suffix=".txt" timestamp="true"/> <Realm className="org.apache.catalina.realm.UserDatabaseRealm"/> </Engine> </Service> </Server>
I have seen this problem in various forums however no one has been able to give a clear answer. I hope somebody out there has faced similar problem earlier and found a solution.
Awaiting your suggestions and replies.
[ jess disabled smilies and added [code] tags ]
[ May 04, 2004: Message edited by: Jessica Sant ]

Hi,
I am deploying multiple WebApplications in WAS 4.0.5. The Global Security settings are active in the Server. This does not allow any application to manipulate the JNDI Tree. However one of my application uses the JNDI tree to bind and unbind a custom Bean.
In the process of unit testing I did not face any problem because I was using a local Single Server Edition with no security settings. Hence unbind operations were occuring preety fine. However since in the full installation there are other applications running too hence in order to avoid any security hastles the Administrator has activated Global Security. This prevents any Context.unbind or Context.rename operation.
I don't want to manipulate the java code of the application because that will be a major enhancement.
I want to know that is it possible to override the Global Security settings for a particular Web-Application.
Kindly provide any information you know. It would be really a great help.

Hi all,
I have an application in Websphere 3.5. I am trying to migrate it to Websphere 4.x. I am facing a problem while doing so. The program logic is so built that a JavaBean which contains session information of Client is binded to the JDNI Tree. This Bean is required to shared between all the App Server Clones. This is binded to the tree when the first Clone is started and unbinded when the last running Clone is shutdown.
The code keeps track of the Clones by using the following method com.ibm.servlet.engine.ServletEngine.getEngine().getInfo() to get the Clone Index (a number starting with 1 and incremented as new clones are started).
The problem is in webcontainer.jar which is supplied with Websphere 4.x containing the com.ibm.servlet.engine.ServletEngine class does not contain getInfo() method. Further other classes of com.ibm.servlet.engine.config package are used in the process to get the Clone Index are also not supplied.
Here is the code snippet for your reference
com.ibm.servlet.engine.config.ServletEngineInfo engineInfo;
com.ibm.servlet.engine.config.TransportInfo transInfo;
java.util.Enumeration suppTrans;
engineInfo = com.ibm.servlet.engine.ServletEngine.getEngine().getInfo();
suppTrans = engineInfo.getSupportedTransportNames();
String cloneIndex = null;
while ( suppTrans.hasMoreElements() )
{
transInfo = (com.ibm.servlet.engine.config.TransportInfo)engineInfo.getTransportInfo((String)suppTrans.nextElement());
java.util.Properties args = transInfo.getArgs();
cloneIndex = args.getProperty(CLONE_INDEX);
}
So I cannot get the information regarding Clone Index if I migrate it to Websphere 4.x and hence the application will not run.
I would request you to kindly suggest any API by which the following can be achieved or incase no such api exists any round about way to achieve the same.
[ December 10, 2003: Message edited by: Rahul Gupta ]

Hi guys,
I am in a process of modifying some codes that was earlier written using jdk1.1.8 and is now to be written using jdk1.3.1. Though it simple to find out the deprecated methods, since they are listed by the compiler itself during the compilation time. However in order to remove codes that previously used round about techniques by codes with enhanced API one should know what are the choices available to one.
Since between jdk1.1.8 and jdk1.3.1 there have been quite a number of versions and the docs of each showing the enhancement done incrementally it is quite difficult for me to understand the choices available to me since I dont have an exhaustive list.
Can you help me out in some way, through which I can remove old codes and put the new ones and what all is available to me.

Hi friends,
Shortly I will be appearing for the SCWCD examination. I had started my preparation. I am studying the book "SCWCD Kit...." by Hanumant, Malviya. I also have some coding experience.
The information I would like know from you that what will be the best Mock Test for the same. When I had appeared for SCJP I gave a number of mock tests but the most wonderful one was that of Dan's Mock Test. I would like to know from you a parallel form in SCWCD.
kindly help

Hi,
Dont forget to take Dan's Mock Test otherwise you will miss something really great..
They are simply mind boggling....shud do it...

Best of Luck,
Try to complete questions quickly and give a exhaustive revision.

Hi all,
Can you tell me in US$ what is cost for SCWCD exam.

hi,
A static inner class can define both static and non-static members. Since non-static member requires an object instance, hence they cannot be referenced using the Class name. On the other hand the static members can be accessed using Class name.
Treat a static inner class as a package-level class and you will find all your answers...

Hi all,
I recently passed the SCJP exam. I wanted to go now for the SCWCD exam. I wanted to know that like the SC Developer exam is there any project to be done or there is only the exam to clear.
Also I would like to know that is there any time limit in terms of months after the SCJP exam that I am eligible for the SCWCD exam.

Great score Man....
keep writing
rahul

Hi,
Just understand thoroughly where Assertions could be used and where it cannot be....thats it...
For example.....assertions should not be used for checking argument of public method but can be used to check arguments of non-public methods....
rahul

hi all,
Well I had been developing RMI applications for quite long...but still there are something which do not understand.....
Well when we start the RMI registry and register our Remote object in it, the RMI registry opens a port at 1099 (default port) and listens for incoming request. When ever a client makes a request with a particular service name the following sequence of events occurs....
1)the registry being itself a remote object the request first obtains a stub of the registry.
2)using the stubb then the lookup method is called and RemoteStub of the Remote Object is obtained.
3)Then using the Remote Object's Stub remote method calls are made.
Now the communication between the client and server ultimately should boil down to socket communication. But where actually the port is mentioned where the Remote object's stub contacts the server.
Somebody told me that its written in the stub class file. But I decompiled it and checked. There is no mention of any port number.
Can anybody help explain of how actually the communication is occuring between the client and the server
rahul

hi raj,
here is the complete picture
byte->short->int->long->float->double
                    ^
                    |
                    char
This means that while traversing in the direction of the arrow no explicit cast is required. But while traversing in the opposite direction explicit cast is required. Also explicit cast is required when there is any conversion between (byte or short) and the char VARIABLES (not literals).
Hope that helps
rahul

[ February 06, 2003: Message edited by: Rahul Gupta ]
[ February 06, 2003: Message edited by: Rahul Gupta ]
[ February 06, 2003: Message edited by: Rahul Gupta ]
[ February 06, 2003: Message edited by: Rahul Gupta ]