Leveraging my Java skills/training

Hey guys - fantastic site.
It's been a great help in studying for the Cert. Exam. Unfortunately, I made a 59 (ARGHH!!) two weeks ago. I'm still studying - I'll get it next time.
I want to know how I might utilize my Java skills - I know I can post my resume (particularly once I become certified) and work for someone else, but having invested so much time and effort, I kind of like the idea of striking out on my own at some point (after some experience).
I realize that this is an elementary question and one that I probably should have asked a long time ago. But :::
What can I really do with Java??
What can I do with Java that I can't do with other languages?
I understand the basics - platform independent... Java drives the internet..and so on etc, etc. But how does one go about really utilizing those aspects. I don't really know how to incorporate java into a whole package that I could sell/market/etc.... It's like I've studied some trees for about 4 months (and I'm getting pretty darn knowledgable about them), but I have no idea what the forest looks like.
Maybe my limited knowledge of hardware is a problem. I don't know how java is fully utilized on the internet (particularly since all I see is HTML).
Give me some ideas..
Forgive me for such a "greenhorn" post. I'm just excited about the possibilities of the language and I am excited to really use it.
Give me some of your ideas/feedback.
Best regards.

Well, it's a general purpose systems language. You can do about anything with it. Some would say it's not the best choice for some problems.
Platform independence is nice but there's so much more. You get a huge library of functions for free. Take the collections API for example. I've worked on C jobs where we had to write and debug that stuff ourselves. With Java you can concentrate more on your problem. Extend this concept to Swing, streams, and internationalization code.
Add on lightweight multi-threading.
Sure, this stuff might come in an add-on proprietary library. But with Java, what you know about collections transfers from one project to the next. It's not one proprietary library at job a and a second on job b.
Seems like most Java projects these days are in the EJB area. This gives you access to security and transactions. In theory, EJB can scale from a low budget system to a high end one with out a major rewrite.

Originally posted by Chris Garrison:

What can I really do with Java??
What can I do with Java that I can't do with other languages?
I understand the basics - platform independent... Java drives the internet..and so on etc, etc. But how does one go about really utilizing those aspects.

I don't support this statement of Java driving the internet. The problem is, JSP pages are interpreted (it uses intermediate entity to run - JVM), and this slows things down considerably. Microsoft seems to go the same path with ASP and .NET. My safest bet would be, that fastest sites out there still use plain old C (or plus-plus), just because it is a fully compiled code.
There are only 2 good alternatives out there for web development (Perl and others slowly becoming obsolete): Microsoft (.NET wave is coming, believe me) and Java. With Microsoft you are stuck with Windows machine, and very quickly run into licensing issues. With Java, on the other hand, you can get away with, say, free Linux. There's also a very good free web server: Apache. Since most of the sites on the internet are created (and maintained) by mortal folks, they don't have cash to pay Microsoft fees it wants. So they use free Java to do the job. Hence, "Java drives the internet" marketing gizmo, created by Sun or IBM.
Plus, Java has a hand on connecting to wireless and mobile devices so loved by management and sales staff.

I don't think there's anything out there that Java can do that C or C++ can't.
Shura
[ May 19, 2002: Message edited by: Shura Balaganov ]

I had this same problem when I first started taking CS classes. Studying for the SCJP really rounded out all the java API for me, but I was still unsure what I can do with it.
While I'm still a bit confused, I can offer the following simplification:
Jave 2 Mobile Edition (J2ME)
- api with small footprint allows you to write programs for mobile devices ranging from cell phones to PDA's to smart chips to anything else that is J2ME enabled. Java is gaining ground here because it promises to allow all types of different mobile devices to talk to each other. Plus, Sun is gathering a lot of support from mobile vendors such as Nokia, Motorola, etc.
Jave 2 Standard Edition (J2SE)
- what the SCJP covers. This is the "standard" so you should know these api's. J2SE allows you to write stand-alone programs, applets. There's no real advantage that Java offers here over other languages besides being platform independent (which isn't a hot seller b/c it doesn't work right a lot of the times).
- servlets and JSP are the other main things included in J2SE and are not in SCJP. These two technologies really drive the back end of web technologies and where the most interest in Java is. Servlets, together used with JSP, are competing technologies with CGI and perl scripting. They are two of the core web technologies that have made Java so popular. If you do any sort of web development with Java, you'll have to know these.
Jave 2 Enterprise Edition (J2EE)
- this is the superset of J2SE and encompasses lots more technologies. Most importantly, (I think, because I haven't ever done J2EE), it involves EJB's. There are tons of J2EE technologies going on, a lot of them involving servlets, jsp and EJB's working together.

Sorry if this answer seems too greenhorn - I don't mean to patronize, but I don't know your level of expertise.
Passing the SCJP won't really do much, except give you grounding knowledge of java. If you really want to do something creative, jump on the J2ME bandwagon and download the Wireless Development Toolkit and start writing programs for mobile devices. That is very new and very few people are experts....that's risky.
If you want the safe route, learn servlets and JSP - two tried an true technologies.
Ok I'm going to bed ....

Shura,
I hope you are not going for J2EE jobs :/
I have worked with iPlanet in C++ and Java and can tell you the Java is much faster. JSP's are only interpreted the first time they are run, then they are compiled, with a jit compiler, cached and... I think are faster than C++.
Oh, and Java required much less code..

Originally posted by Simon Lee:
Shura,
I hope you are not going for J2EE jobs :/
I have worked with iPlanet in C++ and Java and can tell you the Java is much faster. JSP's are only interpreted the first time they are run, then they are compiled, with a jit compiler, cached and... I think are faster than C++.
Oh, and Java required much less code..

Yeah, sure, it is cached, as well as ASP or C++. "Faster" is a relevant term. Do you see biggest sites out there switching to Java? I don't think so. Of course, if you have less than 1000 hits an hour, your site pays the price of instantiating an EXE or DLL or whatever and looks like it is slower. Microsoft had big time troubles switching his sites to ASP. Eventually, MSN and Hotmail are C++. Not sure what Yahoo uses, but I don't see .jsp extentions there either.
For business purposes and for sites where you don't really need speed JSP (or ASP for that matter) is, of course, more convenient.
People shouldn't obsess with one particular technology. As far as J2EE jobs, I'll give you examples.... I've done 2 projects, for 2 Dow Jones 30 companies (no small folks there), one in ASP and the other in JSP, and for their hits ratio either worked just fine.
Oh, I have to highlight this one: THERE IS NO WAY INTERPRETED CODE CAN BE FASTER THEN FULLY COMPILED. Jits or no jits. Unless there is an overhead above it, like for instance, web/app server...We can debate this one if you'd like

Shura
[ May 20, 2002: Message edited by: Shura Balaganov ]

Ok there is no need to debate this one...
write a simple .jsp that spits out "hello world", then do the same in c++.
write an application distributed over 3 webservers and 4 appservers, connection pooled to an oracle database, a feed from reuters and god knows what else.. in c++ and java
I can tell you that you will be unable to detect the difference for your hello world program, I can tell you your fully fledged app will take 4 times as long to write in c++, therefore more code, therefore slower than java.

Originally posted by Simon Lee:
I can tell you that you will be unable to detect the difference for your hello world program, I can tell you your fully fledged app will take 4 times as long to write in c++, therefore more code, therefore slower than java.

Let's define "speed" then. If your definition is "how fast can I create 'hello world' program", then you are correct. If, on the other hand, it is "how fast your average web page can be served", then it's another story.
I've done load tests on ASP sites, single IIS server will max out at about 200 hits/sec, give or take based on RAM, number of CPUs, etc. Therefore if you need more, you load balance, etc. I don't know exact numbers for JSP, but industry speculates they are about the same. Even if it is 300 hits/sec, its still not much. With amount of traffic Yahoo or MSN get, you can load balance all you want, and your JSP site will still choke. There are also bunch of tricks people use to get performance, like cache... But I am talking about pure page load speed.
In business environment most of the times JSP will be a great choice, no doubt.
Oh, and more code doesn't equal to slower execution.

Shura
[ May 21, 2002: Message edited by: Shura Balaganov ]