Import a pkcs12 certificate in java jks keystore

openssl pkcs12 -in ./myfile.p12 -out myfile.pem
openssl x509 -in ./myfile.pem -out myfile.crt
keytool -importcert -alias myfile -file ./myfile.crt -keystore mykeystore.jks

To verify:
keytool -list -keystore mykeystore.jks