is it a good idea to have knowledge of java with mainframe?

Answer 1

Previous answer is so totally wrong on so many different levels! so I will stick to just answering your question. Java runs just fine on mainframes, but you won't see much of it ON mainframes. People don't tend to use mainframes for the kind of stuff Java is good at.

So knowledge of Java is not considered a valuable skill for a mainframe programmer. However, knowledge of SQL is good to know, Cobol even after all these years is still good to know, Mainframe JCL is mandatory, knowledge of ISPF, is mandatory I would think, Still important, but slightly less valuable skills would be CICS, IMS (you'd be surprised how many IMS and CICS shops are still out there), mainframe utilities such as synchsort, are useful, but not essential - most people figure you can pick that up as you go.

For mainframe concentrate on Cobol and JCL first, then SQL probably in conjunction with a Database such as DB/2, Oracle, or Teradata. You will probably learn ISPF as you go along, learning the previous things will force you into ISPF from time to time. with those skills, you would qualify for an entry level mainframe job.

Answer 2

Both are different platform
Different tools are used for coding
Mainframe coding is done by LLL-Low Leve Language (FORTRAN / COBOL, JCL, VSAM, CICS, DB2.........)
Java is High Level Language(Core JAVA, JAVA beans, Java Servlets............)