hbase connection refused

I am new to HBase and Hadoop. I have completely setup HBase and started perfectly. Now when I tried to connect from p1 to HBase (where HBase setup is on p2) using a Java client, then it is throwing a strange exception.

12/04/17 14:36:37 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=192.168.15.20:2181 sessionTimeout=180000 watcher=hconnection
12/04/17 14:36:38 INFO zookeeper.ClientCnxn: Opening socket connection to server /192.168.15.20:2181
12/04/17 14:36:38 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.ConnectException: Connection refused
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1119)
12/04/17 14:36:39 INFO zookeeper.ClientCnxn: Opening socket connection to server hbase.local/192.168.15.20:2181
12/04/17 14:36:39 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.ConnectException: Connection refused
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1119)
12/04/17 14:36:41 INFO zookeeper.ClientCnxn: Opening socket connection to server hbase.local/192.168.15.20:2181
12/04/17 14:36:41 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.ConnectException: Connection refused
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1119)
12/04/17 14:36:43 INFO zookeepe