[CAMEL-18196] POJO-Producing: java.lang.IllegalStateException: Producer has not been started

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Bug
• Affects Version/s: 3.17.0
• Component/s: camel-core, documentation
• Estimated Complexity: Unknown

Language

Java

• Assignee: Unassigned
• Reporter: David Url
• Created: 15/Jun/22 14:31
• Updated: 20/Jun/22 13:34
• Resolved: 16/Jun/22 08:09

Description

I was following the POJO-Producing seciton in the manual in order to have transport agnostic spring beans that produce events. (https://camel.apache.org/manual/pojo-producing.html#_hiding_the_camel_apis_from_your_code)

My setup looks like this:

@Component
public class RecorderSender {

   public static final String ENDPOINT_NAME = "direct:recorderSender?block=true&synchronous=true";

   private ProducerEndpoint<byte[]> endpoint;

   @Produce(RecorderSender.ENDPOINT_NAME)
   public void setEndpoint(final ProducerEndpoint<byte[]> endpoint) {
      this.endpoint = endpoint;
   }

   public void write(final byte[] payload) {
      this.endpoint.send(payload);
   }

}


@InOnly
public interface ProducerEndpoint<T> {

   void send(T object);

}

However once my spring bean is initialized it starts calling RecorderSender.write(byte[]) at a time where the CamelContext is not yet initialized, and I get this exception:

Exception in thread "connector-1" java.lang.IllegalStateException: Producer has not been started: Producer[direct://recorderSender?block=true&synchronous=true]
	at org.apache.camel.processor.EventNotifierProducer.process(EventNotifierProducer.java:54)
	at org.apache.camel.impl.engine.DefaultAsyncProcessorAwaitManager.process(DefaultAsyncProcessorAwaitManager.java:83)
	at org.apache.camel.support.DefaultAsyncProducer.process(DefaultAsyncProducer.java:41)
	at org.apache.camel.component.bean.AbstractCamelInvocationHandler$1.call(AbstractCamelInvocationHandler.java:189)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at org.apache.camel.component.bean.AbstractCamelInvocationHandler.doInvoke(AbstractCamelInvocationHandler.java:207)
	at org.apache.camel.component.bean.AbstractCamelInvocationHandler.invokeProxy(AbstractCamelInvocationHandler.java:169)
	at org.apache.camel.component.bean.CamelInvocationHandler.doInvokeProxy(CamelInvocationHandler.java:43)
	at org.apache.camel.component.bean.AbstractCamelInvocationHandler.invoke(AbstractCamelInvocationHandler.java:81)
	at jdk.proxy2/jdk.proxy2.$Proxy99.send(Unknown Source)
	at com.example.RecorderSender.write(RecorderSender.java:45)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)

I assumed that the properties block and synchronous would ensure that the call is blocking, regardless of the initialization state of the CamelContext.

I'm not sure whether this is actually a bug, or intentional behavior. But it would be nice to have the POJO Producing guide mentioning this behavior, or hinting at a better solution.