Getting Exception in thread “main” java.lang.NoClassDefFoundError: com/azure/core/util/ClientOptions

Question

    I am working on test automating azure event hub functions using java in eclipse.
    
    I am trying to run the receiver application for EventHub functions.
    Below is the output:
    
        Exception in thread "main" java.lang.NoClassDefFoundError: com/azure/core/util/ClientOptions
            at com.azure.storage.blob.BlobContainerClientBuilder.<init>(BlobContainerClientBuilder.java:73)
            at AzureEventHubTest.Receiver.main(Receiver.java:44)
        Caused by: java.lang.ClassNotFoundException: com.azure.core.util.ClientOptions
            at java.net.URLClassLoader.findClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            ... 2 more
    
    
    **Here is the code:**
    
        package AzureEventHubTest;
        
        import com.azure.messaging.eventhubs.EventHubClientBuilder;
        import com.azure.messaging.eventhubs.EventProcessorClient;
        import com.azure.messaging.eventhubs.EventProcessorClientBuilder;
        import com.azure.messaging.eventhubs.checkpointstore.blob.BlobCheckpointStore;
        import com.azure.messaging.eventhubs.models.ErrorContext;
        import com.azure.messaging.eventhubs.models.EventContext;
        import com.azure.storage.blob.BlobContainerAsyncClient;
        import com.azure.storage.blob.BlobContainerClientBuilder;
        import com.azure.messaging.eventhubs.checkpointstore.blob.*;
        import java.util.function.Consumer;
        import java.util.concurrent.TimeUnit;
        import com.azure.core.util.*;
        import com.microsoft.azure.eventhubs.ConnectionStringBuilder;
        import com.microsoft.azure.eventhubs.EventData;
        import com.microsoft.azure.eventhubs.EventHubClient;
        import com.microsoft.azure.eventhubs.EventHubException;
        public class  Receiver {
            private static final String EH_NAMESPACE_CONNECTION_STRING = "//test";
                                                                        //sb://eqix-es-dev-eventhub.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=y3cVul6e5HRi4h30eFNwKBx3YLHaV+A7kQSX40TIeZc=";
            private static final String eventHubName = "//test";
            private static final String STORAGE_CONNECTION_STRING = "//test";
            private static final String STORAGE_CONTAINER_NAME = "//test";
            
            
            public static final java.util.function.Consumer<EventContext> PARTITION_PROCESSOR = eventContext -> {
                 System.out.printf("Processing event from partition %s with sequence number %d with body: %s %n", 
                         eventContext.getPartitionContext().getPartitionId(), eventContext.getEventData().getSequenceNumber(), eventContext.getEventData().getBodyAsString());
        
                    if (eventContext.getEventData().getSequenceNumber() % 10 == 0) {
                        eventContext.updateCheckpoint();
                    }
                };
        
                public static final java.util.function.Consumer<ErrorContext> ERROR_HANDLER = errorContext -> {
                    System.out.printf("Error occurred in partition processor for partition %s, %s.%n",
                        errorContext.getPartitionContext().getPartitionId(),
                        errorContext.getThrowable());
                };
        
                public static void main(String[] args) throws Exception {
                    BlobContainerAsyncClient blobContainerAsyncClient = new BlobContainerClientBuilder()
                        .connectionString(STORAGE_CONNECTION_STRING)
                        .containerName(STORAGE_CONTAINER_NAME)
                        .buildAsyncClient();
        
                    EventProcessorClientBuilder eventProcessorClientBuilder = new EventProcessorClientBuilder()
                        .connectionString(EH_NAMESPACE_CONNECTION_STRING, eventHubName)
                        .consumerGroup(EventHubClientBuilder.DEFAULT_CONSUMER_GROUP_NAME).processEvent(PARTITION_PROCESSOR)
                        .processError(ERROR_HANDLER)
                        .checkpointStore(new BlobCheckpointStore(blobContainerAsyncClient));
        
                    EventProcessorClient eventProcessorClient = eventProcessorClientBuilder.buildEventProcessorClient();
        
                    System.out.println("Starting event processor");
                    eventProcessorClient.start();
        
                    System.out.println("Press enter to stop.");
                    System.in.read();
        
                    System.out.println("Stopping event processor");
                    eventProcessorClient.stop();
                    System.out.println("Event processor stopped.");
        
                    System.out.println("Exiting process");
                }
        }
    
     
    Can anyone please help me to know where am I going wrong?
    What is wrong with my code or if anything else?
    I am stuck due to this.
    
 

These are the added maven dependencies: Included- azureeventhubs dependencies and other: com.azure azure-messaging-eventhubs-checkpointstore-blob 1.1.1 com.azure azure-messaging-eventhubs 5.1.1 org.slf4j slf4j-api 2.0.0-alpha1 org.slf4j slf4j-simple 2.0.0-alpha1 test com.azure azure-storage-blob 12.10.0 org.testng testng 7.3.0 test com.microsoft.azure azure-eventhubs 2.2.0

Answer 1

ClientOptions was introduced in azure-core version 1.9.0 which is used in azure-storage-blob version 12.10.0.

1.1.1 version of azure-messaging-eventhubs-checkpointstore-blob uses an older version of azure-core (1.5.1) which doesn't have ClientOptions . So, at runtime, the older version of azure-core is getting loaded resulting in NoClassDefFoundError when creating BlobContainer that tries to use ClientOptions class.

So, if you upgrade azure-messaging-eventhubs-checkpointstore=blob to 1.5.0 and azure-messaging-eventhubs to 5.5.0, this issue will be resolved.

As a side note, you can remove azure-storage-blob from your dependency list as azure-messaging-eventhubs-checkpointstore-blob transitively includes azure-storage-blob .

Answer 2

NoClassDefFoundError is thrown when a class is not on your classpath. Have you tried the solutions named here? exception in thread 'main' java.lang.NoClassDefFoundError: