java.lang.UnsatisfiedLinkError

You probably have some older MQ jar files either in your CLASSPATH, in the lib or in the EAR.
Remove them and you should be fine.
You should not put MQ files in your EAR or in the WEB-INF/lib folders. They should be in the classpath of your appserver.

As I had to deal with this error myself; and it took me a lot of time to find the right answer, I'd like to share it with the next one, who comes along this thread...

Actually the solution to the problem was very simple (at least in my case). It was not related to any CLASSPATH, java.library.path or installation issues.

I simply forgot to switch the MQConnectionFactory into the Client mode.

This has to be done, by simply calling

cf.setTransportType(WMQConstants.WMQ_CM_CLIENT);

or

cf.setTransportType(WMQConstants.WMQ_CM_BINDINGS_THEN_CLIENT);

or any other connection type, that fits your needs.
By default, the ConnectionFactory is in "Binding" mode (WMQ_CM_BINDINGS), which is intended for local server installations, as it is is stated in the IBM Documentation:

To connect to a queue manager in bindings mode, a WebSphere MQ classes for JMS application must run on the same system on which the queue manager is running.

This transport type is the same as the XMSC_WMQ_CONNECTION_MODE (WMQConstants.WMQ_CONNECTION_MODE) property, when using JNDI or the JmsFactoryFactory.

The same should apply to the other ConnectionFactory types: MQQueueConnectionFactory, MQTopicConnectionFactory, MQXAConnectionFactory, MQXAQueueConnectionFactory and MQXATopicConnectionFactory

Check the IMB Knowledge Center for more information about the different connection/binding options:

https://www.ibm.com/support/knowledgecenter/SSFKSJ_7.5.0/com.ibm.mq.dev.doc/q031720_.htm https://www.ibm.com/support/knowledgecenter/SSFKSJ_7.5.0/com.ibm.mq.dev.doc/q030560_.htm

I came across this while connecting using IBM MQ api. I didn't find this issue to be related to classpath either.

This happened to me when I instantiated MQQueueManager before setting MQEnvironment's hostname and channel. Just ensure that your code does not do that and that it instantiates the manager after the environment is set. Something like..

MQEnvironment.hostname = "mq hostname";
MQEnvironment.channel = "mq channel";
..more code..
this._queueManager = new MQQueueManager(qManager);

(Observed that it's OK to set MQEnvironment.port after MQQueueManager is initialized, but one would probably initialize everything related to MQEnvironment together)