Ubuntu给Connection拒绝了

Question

我正在运行一个本地进程，其URL配置为hdfs：// localhost：9000。 HDFS是一个Hadoop文件系统协议。

While I perform a Unix command on Ubuntu 12.0, it gives below error -

Call From localhost/127.0.0.1 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused;

My /etc/hosts file has below details -

127.0.0.1 localhost
127.0.0.1 ubuntu

/# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

SSH is also in running mode. Not sure how to resolve it. Pleas provide your input.