Nirmal

Did some digging and the NPE is due to the fact that we are invoking a default constructor for whatever connection factory class is provided (i.e., ‘org.exolab.jms.client.JmsConnectionFactory’). And that works for most major JMS providers, however for OpenJMS after looking at the code it is rather clear that the default constructor that is exposed was not exposed to be actually used by the developers but rather internal serialization use. 

/**
     * Default constructor required for serialization
     */
    public JmsConnectionFactory() {
    }

Not sure why it was done this way . . ., but the NPE is due to the fact that the server proxy class is null so when it attempts to do Class.forName(proxyClassName) in getProxy() method it fails with NPE.

One other thing I noticed is that all OpenJMS examples are based on obtaining ConnectionFactory from JNDI for which we currently do not have support. 

Once again, please raise the JIRA if you believe that it’s important to add such feature.

Cheers
Oleg
On Nov 1, 2016, at 9:29 AM, Oleg Zhurakousky <ozhurakousky@hortonworks.com> wrote:

Nirmal

While ConsumeJMS was developed and tested with the idea of supporting multiple providers, ‘openjms’ was not the one that it was tested with. 
I will look at the error and will follow up, but the fact that it already shows NPE means we have a bug somewhere, so please raise the JIRA (https://issues.apache.org/jira/browse/NIFI) if you don’t mind or let m know and I’ll do it.

Thank you for reporting it.
Cheers
Oleg


On Nov 1, 2016, at 8:35 AM, Nirmal Kumar <nirmal.kumar@impetus.co.in> wrote:

Hi All,
 
I am trying to read messages from openjms-0.7.7 using the ConsumeJMS Processor but getting following exception:
 
2016-11-01 14:43:17,260 ERROR [Timer-Driven Process Thread-4] o.apache.nifi.jms.processors.ConsumeJMS ConsumeJMS - JMSConsumer[destination:queue1; pub-sub:false;] ConsumeJMS - JMSConsumer[destination:queue1; pub-sub:false;] failed to process session due to org.springframework.jms.UncategorizedJmsException: Uncategorized exception occured during JMS processing; nested exception is javax.jms.JMSException: Failed to create proxy: java.lang.NullPointerException: org.springframework.jms.UncategorizedJmsException: Uncategorized exception occured during JMS processing; nested exception is javax.jms.JMSException: Failed to create proxy: java.lang.NullPointerException
2016-11-01 14:43:17,265 ERROR [Timer-Driven Process Thread-4] o.apache.nifi.jms.processors.ConsumeJMS
org.springframework.jms.UncategorizedJmsException: Uncategorized exception occured during JMS processing; nested exception is javax.jms.JMSException: Failed to create proxy: java.lang.NullPointerException
        at org.springframework.jms.support.JmsUtils.convertJmsAccessException(JmsUtils.java:316) ~[na:na]
        at org.springframework.jms.support.JmsAccessor.convertJmsAccessException(JmsAccessor.java:169) ~[na:na]
        at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:497) ~[na:na]
        at org.springframework.jms.core.JmsTemplate.receiveSelected(JmsTemplate.java:764) ~[na:na]
        at org.springframework.jms.core.JmsTemplate.receive(JmsTemplate.java:738) ~[na:na]
        at org.springframework.jms.core.JmsTemplate.receive(JmsTemplate.java:727) ~[na:na]
        at org.apache.nifi.jms.processors.JMSConsumer.consume(JMSConsumer.java:65) ~[na:na]
        at org.apache.nifi.jms.processors.ConsumeJMS.rendezvousWithJms(ConsumeJMS.java:79) ~[na:na]
        at org.apache.nifi.jms.processors.AbstractJMSProcessor.onTrigger(AbstractJMSProcessor.java:136) ~[na:na]
        at org.apache.nifi.jms.processors.ConsumeJMS.onTrigger(ConsumeJMS.java:50) ~[na:na]
        at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27) ~[nifi-api-1.0.0.jar:1.0.0]
        at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1064) ~[nifi-framework-core-1.0.0.jar:1.0.0]
        at org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:136) [nifi-framework-core-1.0.0.jar:1.0.0]
        at org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:47) [nifi-framework-core-1.0.0.jar:1.0.0]
        at org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:132) [nifi-framework-core-1.0.0.jar:1.0.0]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_45]
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_45]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_45]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_45]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_45]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_45]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_45]
Caused by: javax.jms.JMSException: Failed to create proxy: java.lang.NullPointerException
        at org.exolab.jms.client.JmsConnectionFactory.getProxy(JmsConnectionFactory.java:169) ~[na:na]
        at org.exolab.jms.client.JmsConnection.<init>(JmsConnection.java:174) ~[na:na]
        at org.exolab.jms.client.JmsConnectionFactory.createConnection(JmsConnectionFactory.java:284) ~[na:na]
        at org.exolab.jms.client.JmsConnectionFactory.createConnection(JmsConnectionFactory.java:266) ~[na:na]
        at org.springframework.jms.connection.UserCredentialsConnectionFactoryAdapter.doCreateConnection(UserCredentialsConnectionFactoryAdapter.java:181) ~[na:na]
        at org.springframework.jms.connection.UserCredentialsConnectionFactoryAdapter.createConnection(UserCredentialsConnectionFactoryAdapter.java:152) ~[na:na]
        at org.springframework.jms.connection.SingleConnectionFactory.doCreateConnection(SingleConnectionFactory.java:365) ~[na:na]
        at org.springframework.jms.connection.SingleConnectionFactory.initConnection(SingleConnectionFactory.java:305) ~[na:na]
        at org.springframework.jms.connection.SingleConnectionFactory.getConnection(SingleConnectionFactory.java:283) ~[na:na]
        at org.springframework.jms.connection.SingleConnectionFactory.createConnection(SingleConnectionFactory.java:224) ~[na:na]
        at org.springframework.jms.support.JmsAccessor.createConnection(JmsAccessor.java:180) ~[na:na]
        at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:484) ~[na:na]
        ... 19 common frames omitted
 
 
I have configured the JMSConnectionFactoryProvider with the following properties:
 

MQ ConnectionFactory Implementation

org.exolab.jms.client.JmsConnectionFactory

Actual

MQ Client Libraries path (i.e., /usr/jms/lib)

/user/nirmal/OpenJMS/openjms-0.7.7/lib

The lib directory for OpenJMS

 
 
I also tried org.exolab.jms.client.JmsXAConnectionFactory in the above #1 property but again the same exception logs.
 
Not sure if somebody tested the ConsumeJMS / PublishJMS processors with OpenJMS?
 
Thanks,
-Nirmal
 








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