Develop Reference

Error Classpath is empty. Please build the project first e.g. by running apache kafka

i was following this step to download apache kafka into my device windows https://www.confluent.io/blog/set-up-and-run-kafka-on-windows-linux-wsl-2/
but when i did this bin/zookeeper-server-start.sh config/zookeeper.properties
i always stuck with this error Error Classpath is empty. Please build the project first e.g.
where my wrong at?

Sounds like you might have downloaded the Kafka sources (labeled src) rather than the binaries
Download the binary link for the desired Kafka version from here: https://kafka.apache.org/downloads

under hange root environment: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directory

Actually I have solved the problem but I don't understand why it works.
I have been developing under a change root environment, which was configured by someone else. I tried to use java command, but got that error message in the title.
After searching for solutions to this problem, I found no one works for my situation. Then I downloaded the newest java package from Oracle website and put it somewhere in my change root environment. By running ./java in .../jre.../bin, I tried test whether this new one works and it did work.
Then the thing I cannot understand happened. After testing the new jre, the old java command is fixed and I don't get the error message any more. I have used "java -version" to check the version of the java command and it was the old version.
Can someone explain?

Can't setup Tomcat 6 in Eclipse - "Could not load the Tomcat server configuration" error

For the last couple of hours, I'm desperately trying to configure apache tomcat6 in Eclipse, and I'm having some difficulties.
I tried everything I could find online, including several posts here in Stack Overflow (most of the problems I found wasn't exactly like mine).
Initially, I followed this tutorial, and after installing tomcat6 like this:
sudo apt-get install tomcat6-common
sudo apt-get install tomcat6
and making sure that the server is running.
Next, I followed the mentioned tutorial, and everything was fine, until I got to stage 5.4 in the tutorial: "Start Server".
When I click Start, I get the following error:
As I said, I tried to look online for an answer, but nothing seems to help...
Does anyone know why am I getting this error and how can I fix this?

This might be a long-shot but do you have correct permissions for the folder where the config file is located?

try to follow the steps mentioned in below link
clipse-could-not-load-the-tomcat-server-configuration
1)Close Eclipse
2)Copy all files from TOMCAT_6_HOME/conf to WORKSPACE_FOLDER/Servers/Tomcat v6.0 Server at localhost-config
3)Start Eclipse
4) Expand the Servers project, click on the Tomcat 6 project and hit F5
5) Start Tomcat from Eclipse

Try to start the server using terminal and then try in eclipse. go to /bin/ execute the command startup.sh. try this.
if you still got error. Execute this configtest.sh will provide you the proper error.
Then try set Classpath for your server. can be done using setclasspath.sh

I was able to solve it, after 3 and a half hours of trying...
Apparently, when I installed tomcat from the command line (sudo-apt-get etc) the /usr/share/tomcat6 folder (the default installation path) was missing some files, including this /conf folder, which required for Eclipse (hence the error message).
But when I removed it, and download tomcat as a tar.gz file from here, and extracted it, it somehow contains more files in it, including the /conf folder.
So then in Eclipse I created a new Server, and provided the path of the new extracted folder, instead of the previous /usr/share/tomcat.
This did the trick.

Trying to set up WebLogic Server but can't locate the JDK

I am trying to set up the WebLogic Server for a class and since I had to download the jar file (because that's what is provided for mac), it doesn't come with a JDK. We are supposed to use our own. My problem is that I can't get it to "see" my JDK.
I have, after searching long and hard, found my JDK folders in Mac>Library>Java> After that there are a few options(Extensions, JavaConfig.plist, JavaVirtualMachines, Support). Within each of these are more and more options…where is the actual "file" that I can point WLS to? Has anyone else had this problem?
Thanks in advance...

Haven't worked with MAC. But in linux installation the JDK is primarily referenced in the following files:
#$MIDDLEWARE_HOME/registry.xml
#$MIDDLEWARE_HOME/user_projects/domains/base_domain/bin/setDomainEnv.sh
#$MIDDLEWARE_HOME/user_projects/domains/base_domain/init-info/domain-info.xml
#$MIDDLEWARE_HOME/user_projects/domains/base_domain/init-info/startscript.xml
#$MIDDLEWARE_HOME/user_projects/domains/base_domain/init-info/tokenValue.properties
Assuming my domain name is "base_domain".
Change the refernce to your JDK in those files. The 2nd file though, is the key.

How to Create, mount , unmount VHD's through java program on windows server 2008?

With reference to VHD Java library , I tried to use libguestfs.. but I am unable to get it work. At the first glance it seems that it is not working on the windows environment.
But for the try I am stuck at first point only, how to get jar file for com.redhat.et.libguestfs.* classes. I might be wrong in my execution plan.. kindly help.
Is there any better way to achieve my goal of creating , mounting , unmounting VHD's through java program.
Thanks in advance...

The Java bindings, which contain the com.redhat.et.libguestfs package, are available as part of the source distribution tarball. This can be obtained from the libguestfs download page; select the latest version, currently 1.18.8.
Alternatively, a pre-compiled JAR might be available from the Maven repository.
Either way, on Windows you likely have to compile the native libguestfs library yourself.