I’m tired of looking this up, so I’m posting it here:
lifted from: http://stackoverflow.com/questions/17695297/importing-the-private-key-public-certificate-pair-in-the-java-keystore
# Create PKCS12 keystore from private key and public certificate.
openssl pkcs12 -export -name myservercert -in selfsigned.crt -inkey server.key -out keystore.p12
# Convert PKCS12 keystore into a JKS keystore
keytool -importkeystore -destkeystore mykeystore.jks -srckeystore keystore.p12 -srcstoretype pkcs12 -alias myservercert
keytool -list -v -keystore mykeystore.jks
aquacastle 