org.apache.camel.impl.DefaultComponent.doStop() - callback at shutdown

[pchandler]

Reference threadID 2266 

"If you component extend DefaultComponent then it should already implement the Service. The idea is then you can override the doStart / doStop methods."

I try to override the doStop in my camel component as shown:

public class MyCamelComponent extends DefaultComponent {

// Other methods createEndpoint, ... 

 /**
   * When the camel context.stop() is called this method should be invoked.
   * 
   * @see http://camel.apache.org/lifecycle.html
   * 
   */
  @Override
  protected void doStop() throws Exception
  {
       System.out.println("doStop()");
       LOG.info( "doStop()");
       // clean-up/release ALL external resources.
       BasicDataSource ds = dataSource();
       if (ds != null)
       {
            try
            {
                 ds.close();
                 LOG.info("Closing database connections for DB " + ds.getUrl() );
            }
            catch (Exception e)
            {
                 LOG.error("Error shutting down database " + ds.getUrl(), e);
                 throw e;
            }
       }
       
       // call the super's stop.
       try
       {
            super.doStop();
       }
       catch (Exception e)
       {
            LOG.error("Error in super.doStop();",e);
       }
  }

}

Created a route that calls my component

  <!-- MyCamelComponent   -->
  <bean id="myComponent" class="com.mycompany.MyCamelComponent">
    <property name="dataSource" ref="dataSource"></property>
  </bean>

  <camelContext id="test" xmlns="http://camel.apache.org/schema/spring">
    <route>
      <from uri="jms:topic:incoming"></from>
      <to uri="myComponent://."></to>
    </route>
   
  </camelContext>

In my junit (note: SpringCamelContext context) I added code:

  /** Stop the camel context. */
  public void tearDown() {
    try {
      LOG.info( "JUnit teardown and stop the camel context " + context.getName());
      context.stop();
    } catch ( Exception e ) {
      LOG.error("Error Stopping Conext", e );
    }
  }

Results

• The route starts

• Route runs successfully

• In the log: JUnit teardown and stop the camel context camel-2

• doStop() does not get called?

Question:

Help: Why doesn't doStop() get called? What am I forgetting?

Again thanks in advance,

Peter.

[davsclaus]

Because you define the component as a spring bean, which makes Spring take charge. eg you define the component as  tag to define start and stop methods to invoke.

http://static.springsource.org/spring/docs/2.5.x/reference/beans.html#beans-factory-lifecycle-initializingbean

[pchandler]

Thanks. I will try adding destroy-method= to the spring bean definition.

<!-- MyCamelComponent   -->
  <bean id="myComponent" class="com.mycompany.MyCamelComponent" destroy-method="cleanup">
    <property name="dataSource" ref="dataSource"></property>
  </bean>
 

[pchandler]

1. Tried adding the  'destroy-method' attribute on the <bean/>:

<!-- MyCamelComponent   -->
  <bean id="myComponent" class="com.mycompany.MyCamelComponent" destroy-method="cleanup">
    <property name="dataSource" ref="dataSource"></property>
  </bean>
 

2. Tried implementing the org.springframework.beans.factory.DisposableBean:

public class MyCamelComponent extends DefaultComponent implements DisposableBean {
 
// Other methods createEndpoint, ... 

  /**
   * Part of the spring lifecycle. 
   * 
   */
  public void destroy()
  {
       System.out.println("cleanup()");
       LOG.info( "cleanup()");
       // clean-up/release ALL external resources.
       BasicDataSource ds = dataSource();
       if (ds != null)
       {
            try
            {
                 ds.close();
                 LOG.info("Closing database connections for DB " + ds.getUrl() );
            }
            catch (Exception e)
            {
                 LOG.error("Error shutting down database " + ds.getUrl(), e);
            }
       }
       
       // call the super's stop.
       try
       {
            super.doStop();
       }
       catch (Exception e)
       {
            LOG.error("Error in super.doStop();",e);
       }
  }

No luck. My Custom Camel component method does not get called when the SpringCamelContext is stopped or destroyed.

My work around is to call it myself:

           MyCamelComponent comp = (MyCamelComponent)context.getComponent("myComponent");
           if (comp != null)
                comp.destroy();
           context.stop();
           context.destroy();

Question: Any ideas? Both the springframework and camel will not invoke a stop/destroy method. Seems odd?

[njiang]

Is the context in your code a SpringApplicationContext or a CamelContext?

Willem

[davsclaus]

Ah you need to stop Spring as well in your unit test in the tear down.

Looks like you are just stopping Camel only.

In fact you can just stop Spring, which in turn would stop Camel as well.

[pchandler]

SpringCamelContext

XML namespace is:

  <camelContext id="Test" xmlns="http://camel.apache.org/schema/spring">

The Java start context is:

  /** Camel context used to start scenarios. */
  protected org.apache.camel.spring.SpringCamelContext context;

[pchandler]

"In fact you can just stop Spring" ?

I am calling the "stop()" method on class org.apache.camel.spring.SpringCamelContext in my Junit tearDown().

How do I stop Spring?

From above:

/** Stop the camel context. */
  public void tearDown() {
    try {
      LOG.info( "JUnit teardown and stop the camel context " + context.getName());
      context.stop();
    } catch ( Exception e ) {
      LOG.error("Error Stopping Conext", e );
    }
  }

[davsclaus]

Can you post the source for your unit test?

[pchandler]

Claus,

Sorry, I wish I could but I can not release any source code.

Peter.

[davsclaus]

If you have a fuse support subscription you can run your problem that way.

[pchandler]

The answer:

To get Spring to call the destroy-method(s) you need to set  registerShutdownHook on the ApplicationContext

         // Create/setup String Context in OSGi
        OsgiBundleXmlApplicationContext osgiContext = new OsgiBundleXmlApplicationContext(yourOSGiSpringXMLfile); 
        osgiContext.registerShutdownHook();

The registerShutdownHook in spring:

If you are using Spring IoC in non web application and want to gracefully shutdown all resources we use registerShutdownHook(). This method calls the relevant destroy methods. In order to register a shutdown hook, you have to call the the registerShutdownHook() method which found in the AbstractApplicationContext class.