How to ensure server certificate is created with which private key through java

Customer has created key and certificate using openssl command below

openssl req -newkey rsa:1024 -sha1 -keyout OCkey.pem -out OCreq.pem -subj "/C=country/L=city/O=OCserver/OU=myLab/CN=OCserverName/" -config req.conf

openssl ca -in OCreq.pem -cert CAcert.pem -keyfile CAkey.pem -out OCcert.pem -days 3650 -config sign.conf -extfile sign.ext -md sha1 -notext

So they have given me the certificate(OCcert.pem) and private key (OCkey.pem).

How to ensure that OCcert.pem is created through OCkey.pem using Java?

Note :I can't ask customer开发者_Go百科 to change the ssl command.

Please help.

they have given me the certificate(OCcert.pem) and private key (OCkey.pem)

Why? They should throw that private key away immediately, it is compromised. What was the purpose of this exercise?