Learning Java while working with COBOL on the iSeries

[Lenny2113]

Good day all.
I have a sort of dilemma here. I was hoping some of you may have had similar experience...
I have worked with OS/390 COBOL for about 14 years now. I switched to iSeries just this year - 8 month experience so far.

I always wanted to learn JAVA and do a full transition into OO world of programming. Picked up a few books, took JAVA course, but with COBOL remaining my day-to-day thing, I find it hard to get into JAVA. In addition to that, I am the only developer in my company, so I still learn perks of iSeries.
I am looking to take a college course in C++ with an intent to build foundation of PC related programming language. Then take a college class in OO concepts and then take JAVA Architecture.

Please, share your opinion on Pros and Cons.

Thank you kindly.
Happy Holidays and God Bless.

[BenThurley]

Re: Learning Java while working with COBOL on the iSeries

C/C++ is good to learn because you can use those languages to write ILE modules on the iSeries, but as languages go I would say C++ is harder to learn than Java. Java ties in fairly well with ILE, though not as well as C/C++, you can call Java methods from RPG. Java also has a larger open source community so there are countless components and tools you can get your hands on for free.

You can't do the object oriented bits in RPG so calling components in either C++ or Java is limited in this respect. I'm sorry I don't know anything about COBOL.

I don't think syntax will be your problem. A for loop is a for loop in any language. The hard part will be the OO concepts and learning the class libraries available. The only way to learn these is by a combination of reading and coding.

In terms of which books, my personal favourites are the head first series. Head first Java would be my first purchase and I would also recommend the books on design patterns and servlets and JSP's.

BTW - I have a number of Java projects I keep meaning to do to brush up but I just don't get round to. I'm hoping to make a start on these next year...

[Lenny2113]

Re: Learning Java while working with COBOL on the iSeries

Hi Ben,

Thank you for your time. I recall you were helping me a few month ago on my first encounter with JSP

I feel I am getting lost with all the components that relate to Java. Just "Core Java" is not enough to code a business aplication. Swing, Flex, Spring, JSP, XML, XSL... the list can go on.
I started looking at iText for Java as there is a need for my company to switch the way we print forms from the "old - converter box" to "new - let's say .PDF". I am missing a lot of Java related aspects at this point. But in addition to it all, I really do not know what route to take in my learning process. I wish I had a person here next to me who knows Java and works with it on daily basis. I would be able to learn from the pro. Unfortunately, like I said before, I am "the IT department"

[Lenny2113]

Re: Learning Java while working with COBOL on the iSeries

Could someone suggest if the transition from COBOL to C++ and C++ to Java would be easier then COBOL to Java ?

Please share your thoughts on this. COBOL is procedural 3rd generation language. It is different from RPG in syntax and does not have any API libraries like Java

College curriculum is structure in such way that you need to take C++ and OO programming prior to taking Java.

Thanks,
Lenny

[Mercury]

Re: Learning Java while working with COBOL on the iSeries

COBOL is quite close to RPG and is also a 3GL.

I am about in the same situation however being a RPG programmer I just bought the book "Java for RPG programmers" from MC Press online that I haven't received yet. Hopefully I can let you know how I feel and what I think after a few days of learning.

A last word. IMHO I would dive straight into JAVA and so avoid the C/C++ additional hassle but that's only my opinion.

[littlepd]

Re: Learning Java while working with COBOL on the iSeries

COBOL is quite close to RPG and is also a 3GL.

I am about in the same situation however being a RPG programmer I just bought the book "Java for RPG programmers" from MC Press online that I haven't received yet. Hopefully I can let you know how I feel and what I think after a few days of learning.

A last word. IMHO I would dive straight into JAVA and so avoid the C/C++ additional hassle but that's only my opinion.

I concur. But being a Business Partner, I had IBM java programmers I could call when I got stuck (which was a lot!). So that made it easier for me.

[BenThurley]

Re: Learning Java while working with COBOL on the iSeries

I can tell you now it won't be easier to learn C++ and then Java. C++ is more complicated than Java. C++ is also more powerful than Java and performance is better but for most people it is unnecessary overhead. Java is based on C++ but it is a much stricter OO language. This coupled with the myriad free tools and IDE's available are the reasons why Java was the core language used while I was at university.

IMHO, if you want to learn OO programming then Java is the best place to start. C# is also quite good if you want to go the .net route but I find it always lags behind Java a bit in terms of tools and language features. Plus, you generally have to pay in an enterprise environment. (There is an express version of visual studio to play with)

It will take time to learn though as it's a completely new paradigm. You can write something with iText just using core Java but you'll need to know the OO basics. If you only want to create some simple web pages then PHP might be quicker to learn. You can write OO PHP or just as regular scripts and functions. The downside is it's not as flexible and powerful as Java and it's still a scripting language.

If a scripting language appeals to you but you want the power and platform independence of Java then you should look at something like Groovy, JRuby or Jython. These are syntactically the same as scripting languages but they compile down to Java bytecode. This means you get the same end product as if you'd written the application in Java! JRuby is a port of Ruby, Jython is a port of python and Groovy is a hybrid mix of various scripting languages.

It sounds to me like you already have some real requirements for the iText project. That's ideal because you only need to know core Java for that. There's no swing, no web pages, just a bit of I/O and core Java. I used the iText in action book to learn the framework but I already knew Java at this point.

[Lenny2113]

Re: Learning Java while working with COBOL on the iSeries

I jump from "Thinking in Java" to "Head First Java" to "Building Java Programs" and practice and write code and look at working code trying to see what it does and how. Than, I turn to my COBOL daily work for a week without touching Java ... I understand flow of control, loops and some other basics. I looked at some "webfacing" converted peices and I have to say that there is very little I understand about how these things are tight together. I understand when I read about Objects in Java, but then I think in terms of procedures and my Java class logic looks like a COBOL procedure written in Java code.
I did not get to GUI and I know it is not a one day learning process. I know that it may take several month and for some years to be fully comfortable coding in a new language.
But, "I need it and I want it now" and that seems like a wrong approach.

Taking Java in college without taking C++ first is not allowed by the Computer Sciense Dept.
Your input is greatly appreciated.

Thank you