jdbc -Connection fail in suddnly

Hi All,

I got a Abnormal problem in my Posthresql DB running on RedHat 7.0
yesterday It work with JDBC application.

My Prpblem is It say fail to connect no suitable driver. but I put jdbc
drivers(jar) files in jdk/jre/lib/ext directory and set the all
classpths and it work fine in last few months but i got this error
suddnly.
So I did fresh installation in another machine and do the configuration
It got same error.
Only thing in 2 nd PC is partition for data directory where data base
data is stored. /data/pgsql/data/base

What can be happen..?
please advice me
Thank in advance
regards
Manoj