I tried to implement a simple producer consumer example with kafka and I achieved with the following properties:
Properties configProperties = new Properties();
configProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,"localhost:" + portNumber);
configProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.ByteArraySerializer");
configProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringSerializer");
// Belirtilen property ayarlarına sahip kafka producer oluşturulur
org.apache.kafka.clients.producer.Producer producer = new KafkaProducer(configProperties);
However when I try the exact same configs, and everything else the same, in another project which is a plugin for a data visualization software, I got this error:
.... // Here there is some other stuff but I thing the important one is the below one
Caused by: java.lang.NoClassDefFoundError: org/apache/kafka/clients/producer/Producer
at App.MyControlPanel.<init>(MyControlPanel.java:130)
at App.CytoVisProject.<init>(CytoVisProject.java:29)
... 96 more
Caused by: java.lang.ClassNotFoundException: org.apache.kafka.clients.producer.Producer
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 98 more
In the first one that I said it worked, I was using "mvn clean compile assembly:single", but in the second one I created a jar file for the whole project. Because the visualization software wants a jar file to install the plugin. Since every thing is same (At least I could not find any difference, I used same code) I guess the problem is about the way build the project. What happened here? What is the difference between "mvn clean compile assembly:single" and building a jar file in IntelliJ? Why I got this error and how to fix this? Thanks a lot for help!
As I said in the last comment of the first answer, I have a plugin which has manifest and transform as goal. Here:
<plugin>
<groupId>com.springsource.bundlor</groupId>
<artifactId>com.springsource.bundlor.maven</artifactId>
<version>1.0.0.M2</version>
<configuration>
<outputManifest>C:\Users\USER\AppData\Local\Temp\archetype2tmp/META-INF/MANIFEST.MF</outputManifest>
<failOnWarnings>false</failOnWarnings>
<removeNullHeaders>true</removeNullHeaders>
<manifestHeaders><![CDATA[Bundle-ManifestVersion: 2
Bundle-Name: CytoVisProject
Bundle-SymbolicName: CytoVisProject
Spring-DM-Version: ${pom.version}
]]></manifestHeaders>
</configuration>
<!-- generate the manifest automatically during packaging -->
<executions>
<execution>
<id>bundle-manifest</id>
<phase>package</phase>
<goals>
<goal>manifest</goal>
<goal>transform</goal>
</goals>
</execution>
</executions>
</plugin>
If I use a shade plugin like below:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.1.0</version>
<configuration>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
It does not works, because I need to use manifest and transform as goals in my plugin. How can I add kafka classes to the jar file that IntelliJ creates to solve this problem (I am not sure if this can solve or not)?
I've found an easier solution. I have changed
kafkaProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringSerializer");
to this
kafkaProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
And afterwards my code run, also as part of a pre-compiled plug-in.
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