authorized_keys keytool

[Cesar Augusto <cesar.guzman@xxxxxxxxxxx>]

Hi everybody
I have a keypair generated for keytool from java
that keypair was generate with -keyalg RSA and -keysize 1024 and storage 
in ssh.jks file
with this file How can I do to obtain the id_rsa and id_rsa.pub files?

thanks for all