Here a link to simple ros node: listener

there is a way to create anonymous node:

# In ROS, nodes are uniquely named. If two nodes with the same
# node are launched, the previous one is kicked off. The
# anonymous=True flag means that rospy will choose a unique
# name for our 'listener' node so that multiple listeners can
# run simultaneously.
rospy.init_node('listener', anonymous=True)

How i can do the same functionality in rosjava?

Thanks, Tal.