Connector SAP R3

Hello community. In an application that I am developing, I have to connect to a SAP R3 system, I have obtained the sapjco3 jar. But I need some guidance. Could someone tell me where can I get information on how to connect and work with SAP data? in principle it will only be for consultation, I do not need to write in SAP. Thanks in advance for your help.
1 answers

Have you tried with ?