exception Input not an X.509 certificate

exception Input not an X.509 certificate

sorry I am a dummy.
I have a file which contain :
-----BEGIN CERTIFICATE-----
(many lines of 64 bytes)
-----END CERTIFICATE-----
I use keytool.exe -printcert -file (myfile)
it output like this
Certificate[1]:
Owner: CN=www.mydomain.xxxxxx
(bah bah bah............)
(bah bah bah............)
Certificate[2]:
Owner: CN=Thawte SSL CA, O="Thawte, Inc.", C=US
(bah bah bah............)
(bah bah bah............)
Certificate[3]:
Owner: CN=thawte Primary Root CA, OU="(c) 2006 thawte, Inc. - For
authorized use only", OU=Certification Services Division, O="thawte,
Inc.", C=US
(bah bah bah............)
(bah bah bah............)
Is it normal that it contain 3 certs?
is it call cert chain?
what can I do if I want this file import to keystore?
I try over and over again by keytool.exe -import -alias (myalias)
-trustcacerts -file (thisfile) -keystore (mykeystore)
it keep tell me
java.lang.Exception: Input not an X.509 certificate