Error in definition of default taskScheduler

[SujitB]

Hi,

I'm trying to supply a "taskScheduler" to my SI implementation, and getting a Class Not Found error for "org.springframework.integration.scheduling.Simple TaskScheduler" class.

I'm currently using SI 2.0.0M5.

Here is the application XML (an edited version):

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:si="http://www.springframework.org/schema/integration"
	xmlns:si-xml="http://www.springframework.org/schema/integration/xml"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:task="http://www.springframework.org/schema/task"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
			http://www.springframework.org/schema/beans/spring-beans.xsd
			http://www.springframework.org/schema/integration
			http://www.springframework.org/schema/integration/spring-integration.xsd
			http://www.springframework.org/schema/integration/xml
			http://www.springframework.org/schema/integration/xml/spring-integration-xml.xsd
			http://www.springframework.org/schema/context 
			http://www.springframework.org/schema/context/spring-context.xsd
			http://www.springframework.org/schema/task 
			http://www.springframework.org/schema/task/spring-task.xsd">

	<!-- Setup -->
	<context:mbean-server />
	<context:mbean-export registration="replaceExisting" server="mbeanServer" />
	<context:component-scan base-package="...." />
		
	<bean id="serverConnector" class="org.springframework.jmx.support.ConnectorServerFactoryBean" />
	<bean id="appContextManager" class="....AppContextManager" />
	

        <bean id="taskScheduler" class="org.springframework.integration.scheduling.SimpleTaskScheduler">
              <constructor-arg ref="taskExecutor" />
       </bean>
       <bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
          <property name="corePoolSize" value="3" />
          <property name="daemon" value="true" />
          <property name="keepAliveSeconds" value="60" />
          <property name="maxPoolSize" value="10" />
          <property name="queueCapacity" value="8" />
          <property name="rejectedExecutionHandler">
              <bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy" />
          </property>
          <property name="threadNamePrefix" value="tx.node" />
          <property name="waitForTasksToCompleteOnShutdown" value="true" />
      </bean>	
     
</beans>

The error log is as following:

Exception in thread "main" org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [org.springframework.integration.scheduling.SimpleTaskScheduler] for bean with name 'taskScheduler' defined in file [...\contexts\node-spring-context-main.xml]; nested exception is java.lang.ClassNotFoundException: org.springframework.integration.scheduling.SimpleTaskScheduler
	at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1235)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:576)
	at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1304)
	at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:870)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:556)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
	at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:140)
	at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:84)
	at com.sita.typex.taxi.node.TaxiNodeMain.main(TaxiNodeMain.java:20)
Caused by: java.lang.ClassNotFoundException: org.springframework.integration.scheduling.SimpleTaskScheduler
	at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
	at org.springframework.util.ClassUtils.forName(ClassUtils.java:257)
	at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:408)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1256)
	at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1227)
	... 9 more

[plecesne]

I haven't tried using schedulers yet, so I won't tell you whether this is the best solution doing it.
However, I can tell you two things:

1. You shouldn't have to provide the class of the task scheduler. I believe if you don't provide it, it will use the default implementation. I haven't checked though so I may be wrong... You'll tell me
   
   
2. SI simply doesn't have such a class... Maybe "any more". Chances are that the implementations of schedulers were moved to Spring core with a different package and the documentation hasn't been updated yet.

As far as I can see, there are three implementations of TaskScheduler, all three of them in Spring Core.

• org.springframework.scheduling.concurrent.Concurre ntTaskScheduler
• org.springframework.scheduling.concurrent.ThreadPo olTaskScheduler
• org.springframework.scheduling.concurrent.TimerMan agerTaskScheduler

Check the javadoc to know which one would suit best your needs. I believe the ThreadPoolTaskScheduler is the default implementation.

[oleg.zhurakousky]

SimpleTaskScheduler was removed as we now rely on scheduling support provided by Spring 3.0 via <task:...> namespace. See: http://static.springsource.org/sprin...cheduling.html

[GPS]

use something like this:

<channel id="myChannel">
<dispatcher task-executor="camThreadPoolTaskExecutor" failover="false" />
</channel>

<task:executor id="camThreadPoolTaskExecutor" pool-size="15-25"
queue-capacity="100" rejection-policy="DISCARD_OLDEST" keep-alive="15" />

Oleg, I have a question from this: do you have any suggestion about how to optimize the values for different params defined in the task executor?

[srikondoji]

GPS: For task executor "camThreadPoolTaskExecutor" pool-size of 15-25, how many messageHandler EndPoints you need to define to consume messages from channel "myChannel"?
Thanks
sri

use something like this:

Oleg, I have a question from this: do you have any suggestion about how to optimize the values for different params defined in the task executor?

[GPS]

I just have one message handler endpoint, consuming the messages coming on mychannel.
myChannel is actually a wiretap on around 10-15 different direct channels in spring context, and I need to convert and persist their contents in DB, asynchronously behind the scenes.