Yes. get() removes the message from the queue unless you have specified MQConstants.MQOO_BROWSE in the accessQueue() method.
API documentation below. Look for openOptionsArg in the accessQueue() method. http://pic.dhe.ibm.com/infocenter/wmqv7/v7r5/index.jsp?topic=%2Fcom.ibm.mq.javadoc.doc%2FWMQJavaClasses%2Fcom%2Fibm%2Fmq%2FMQQueueManager.html