When we are using example code for convert PFX to JKS effective file doesn't containvaild key pair. By using Portecle software we can verify file and identify the difference between this created with Chikat and this one, created with Java keetool oraz Portacle. Chilkat jks contains only one key, when the second contains key pair. In both cases we are usining the same pfx file.
Please send a sample pfx, along with a sample jks file create by Portacle so that I may see the difference. You may send it to firstname.lastname@example.org