cloudera manager installation failed! - oracle-j2sdk1.7 installation failed! - ubuntu server

[#1]

I am trying to install the cloud manager by this process

http://www.cloudera.com/documentation/manager/5-1-x/Cloudera-Manager-Installation-Guide/cm5ig_instal...

but getting this error

Log file:

/var/log/cloudera-manager-installer/3.install-oracle-j2sdk1.7.log

----------------------------------
Reading package lists...
Building dependency tree...
Reading state information...
The following NEW packages will be installed:
oracle-j2sdk1.7
0 upgraded, 1 newly installed, 0 to remove and 188 not upgraded.
Need to get 142 MB of archives.
After this operation, 292 MB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
oracle-j2sdk1.7
E: There are problems and -y was used without --force-yes

Server Information:

Distributor ID: Ubuntu
Description: Ubuntu 14.04.5 LTS
Release: 14.04
Codename: trusty

[#2]

Hello @srpanda

Are you deploying your cluster on VM ??

[#3]

Hi @srpanda,

You need to have installed Java on your host.

Regards,

Manu.