It seems like these fields below can be retrieved via Eikon Excel RData() function.
EJV.C.PREFERREDRIC EJV.C.ACCRUALDATE EJV.C.Description EJV.C.INDUSTRYSECTORDESCRIPTION EJV.X.YLDMTHD EJV.C.FIRSTCOUPONDATE
I'm wondering if I can get these fields data via API calls?
If so, is it available in Java language?
Does it work based on Web Services or SFTP or Socket connection?
You can retrieve these Eikon v3 style fields or equivalent Eikon v4 style fields (TR.PreferredRIC; TR.FiAccrualDate; TR.FiDescription; TR.FiIndustrySectorDescription; TR.YLDMTHD; TR.FiFirstCouponDate) using DEX2 COM library. You can find examples in the Eikon COM APIs section on this portal. What determines whether DEX2 library retrieves Eikon v3 or Eikon v4 style fields is the initialization procedure. For details see the following document on Customer Zone and/or the tutorial on this portal:
Although not officially supported, DEX2 library can be used in Java. But you'd have to build a bridge between Java and COM using JNI.
The underlying data retrieval mechanism is Web services, which are not exposed directly. They are only accessible through this COM library.
I hope this helps.