Instrumentation Agent does not produce traces

[HackiHaakert]

I wrote a little Hello World program in Java 21 with several methods calling each other. I included no database and no remote communication. To be able to instrument Java methods I added the annotation dependency and the annotation “@WithSpan”.

@WithSpan
public static void method1() {
System.out.println("Method 1 called");
try {
Thread.sleep(100);  // 100 Milliseconds
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
method2();
}

Annotation dependency:

    <dependency>
        <groupId>io.opentelemetry.instrumentation</groupId>
        <artifactId>opentelemetry-instrumentation-annotations</artifactId>
        <version>2.4.0</version>
    </dependency>

Then I use a shell script to start the Application:

#!/bin/bash

export OTEL_SERVICE_NAME=Hello-world
export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317
export OTEL_EXPORTER_OTLP_PROTOCOL=grpc
export OTEL_TRACES_EXPORTER=otlp  # Enable OTLP exporter for traces
export OTEL_METRICS_EXPORTER=none  # Disable metrics exporter
export OTEL_LOGS_EXPORTER=none  # Disable logs exporter
export OTEL_EXPORTER_OTLP_INSECURE=true  # Allow insecure connection
export OTEL_INSTRUMENTATION_OTENTELEMETRY_INSTRUMENTATION_ANNOTATIONS_ENABLED=true

# Start the Java program with the OpenTelemetry Java agent
# Start the Java program with the OpenTelemetry Java agent
java -javaagent:./opentelemetry-javaagent.jar -jar ~/DemoProjekte/HelloWorld/out/artifacts/HelloWorld_jar/HelloWorld.jar

I use agent version 2.4.0. There arrive no spans in my OTEL-Collector.
I changed the traces exporter to console but also no spans for a trace are generated.
The output is:

OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
[otel.javaagent 2024-06-22 09:18:11:328 +0200] [main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 2.4.0
Hello and welcome!
Method 1 called
Method 2 called
Method 3 called
Hello, World!
Waiting for exit

What is my error?