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Technical FAQ: Questions about WebLogic products and other software

FAQ Index

Problems loading shared libraries on UNIX

Q I just installed WebLogic on my UNIX system and I am having trouble loading the shared libraries.

A You probably need to set the file permissions on your .so or .sl files in the weblogic/lib directory to make them executable. The UNIX command to do this is:

      $ chmod a+x *.sl *.so
For more information see Troubleshooting problems with shared libraries on UNIX.

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Handling exceptions with WebLogic EJB from a Visual Basic client

Q We are using WebLogic COM from a Visual Basic client to access EJBeans which are deployed under WebLogic. If a bean method throws an exception, is it possible to get the exception object, invoke a method on it and then determine if the error generated by Visual Basic is a ValidationException or a RemoteException?

A Unfortunately, there are many things you can't do in Visual Basic that you can in Java. When using Visual Basic, you are limited to looking up RMI and EJB objects and calling methods on those objects. In this instance, the best way to handle exceptions is to catch them in the EJBean and return an error message or code to the Visual Basic client.

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Netscape Communicator 4.01 Security Exception

Q I'm using Windows NT and Netscape Communicator. Since I installed the latest version of Netscape, I'm getting the following error when I try to access the WebLogic Server running on the same host via HTTP:

# Security Exception: Couldn't connect to <mybrowser client>
   with origin from <local-classpath-classes>
What's the problem?

A The latest version of Netscape's browser doesn't allow an applet to load classes in your local CLASSPATH. All classes must be loaded "over the wire" to satisfy Netscape's security restrictions.

The solution to this problem is to unset CLASSPATH in your general environment, so that you can start the browser in an environment that has no CLASSPATH.

Then, at the prompt in the shell from which you will start WebLogic Server, set your CLASSPATH. See Setting up and starting WebLogic Server for complete instructions on setting your classpath and starting WebLogic Server.

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Why am I getting an access violation in Netscape?

Q I'm using a native jdbcKona driver and the Netscape Enterprise Server. When I try to execute a jdbcKona query, I get an HTTPD.EXE access violation. No error message is recorded in my Netscape Enterprise server log. I've verified that the connection to my Sybase DBMS is working with utils.dbping, as you instructed in the installation instructions. What is the problem?

A You cannot use type-2 native jDriver drivers with the server-side Java in the Enterprise Server because Netscape does not allow third-party Java with native methods. You can use WebLogic JDBC or one of the Type 4 jDriver drivers, since they are Java-only. BEA has type 4 drivers available for Microsoft SQLServer and Informix. You can also use the JConnect type 4 driver, available free from Sybase. This will also solve the problem with Enterprise Server.

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How do I use the jdbcKona two-tier drivers with Visual Cafe?

Q I want to use one of your two-tier JDBC drivers with Visual Cafe. How do I set it up?

A The distribution includes a copy of the .dll for the jdbcKona driver that ends in a trailing _g, for example, weblogicsql14_g.dll. Under Windows NT, the .dll has been linked with javai_g.dll to provide better compatibility with Visual Cafe's debugger facility.

To use the BEA jDriver 2-tier drivers with Cafe, both WebLogic .dlls -- the one you installed in java/bin as well as the WebLogic *_g.dll -- should be installed in cafe/bin and cafe/java/bin.

Note: Visual Cafe requires CLASSPATH to be set in the configuration file sc.ini, which is found in the /bin directory. Visual Cafe will not read the system environment variable CLASSPATH. From the Project pulldown menu select "Options" and click on the Directories tab. Select "Native Library Files" and type or browse to the location of the native JDBCKona driver files. For Windows NT this would be <WEBLOGIC_HOME>\bin. See the Visual Cafe documentation for more details.

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Running WebLogic with Microsoft SDK for Java

Q I downloaded your software and tried unsuccessfully to run WebLogic Server against my installation of Microsoft SDK for Java. Why doesn't it work?

A You can run WebLogic Server with Microsoft SDK for Java, that is certified for your version of WebLogic Server. See, the platform support page for more information. Additional points to consider if you use the Microsoft SDK with WebLogic Server are as follows:

  • Microsoft SDK for Java, version 3.2 is a Java 1.1 implementation.

  • When using Microsoft SDK for Java, it must to be used to run both the client application and WebLogic Server. The combination of Microsoft SDK for Java running on one side with a Sun Java Virtual Machine (JVM) running on the other side is not supported.

  • When you install WebLogic Server on Windows NT, be sure to use the InstallShield installer. This will install the required library in the lib subdirectory. This zip file must be added to your server's CLASSPATH when starting the server using the Microsoft SDK for Java (this is automatically done for you, if you start the server using the startWeblogic.cmd script included in the distribution). These special classes are not included in the zip file distribution.

  • The Microsoft JVM is named Jview.exe. When you install Microsoft SDK for Java, Jview.exe is installed in the bin directory of the Microsoft SDK for Java directory. Note that some other Microsoft products, such as Internet Explorer, install Jview.exe in the WINNT directory. If you have problems with Jview, check your PATH to be sure that the correct version of Jview is executing.

  • Instructions for starting WebLogic Server using Microsoft SDK for Java are available in Setting up and starting the WebLogic Server.

    The WebLogic RMI compiler, weblogic.rmic, and the WebLogic EJB compiler, weblogic.ejbs, generate Java code and then call a Java compiler. The default compiler is javac, which is the name of the compiler included in JDKs based on the JavaSoft reference implementation. If you do not have the JavaSoft JDK installed, you must specify the compiler to use on the weblogic.rmic or weblogic.ejbc command line. For example:

      $ jview weblogic.rmic -compiler jvc my.class
      $ jview weblogic.ejbc -compiler jvc mybean.ser

  • Undeploying and redeploying EJBeans (the "hot deploy" feature) is not supported with WebLogic Server running with Microsoft SDK for Java.

  • WebLogic Enterprise Connectivity (IIOP connection pools to WebLogic Enterprise) cannot be used with Microsoft SDK for Java.

  • After you install Microsoft SDK for Java, and before you use WebLogic Server, execute clspack -auto, which unloads the Java system classes from the Microsoft JVM to the WINNT\java\ file.

  • Microsoft SDK for Java does not have a jar utility, but the build scripts for the Enterprise JavaBean examples require a jar utility. To build the EJB examples, you must first install a JavaSoft Java Developers Kit (JDK), which you can download from the JavaSoft website. Then, in your development shell, you must do two things:

    1. Add the JavaSoft JDK's bin directory to the end of your Windows NT PATH environment variable.

    2. Add the JavaSoft JDK's lib/ file to the end of your CLASSPATH environment variable.

    You can make these changes in the setEnv.cmd script in your WebLogic directory. See Setting your development environment for more on this script.

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Last updated 01/13/2000