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Please help me choosing the language and framework for my undergraduate project [closed]

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I am a final year computer science student from Mumbai University, India.
The topic of our undergraduate project is SOA.
Under this project we are supposed to build 3 service components and one example website that uses those components.
I am quite good with Java and have no experience whatsoever with C# or .NET.
I am having hard time deciding the language and platform for our project.
Can you please suggest what platform I should go for?
Please give me a brief comparison between Java/Java EE and C#.NET/ASP.NET in terms of complexity, ease of development, ease of deployment etc.
Edit:
The original reason why I put this question is:-
We have to do final year project in group of three. My both partners want to do this project in C# and asp.net and I want to do it in java. Since our project is more of server side, java holds some advantages like cross platform over C#
Also this point:-
What if we implement 2 parts in C#.net(which they will build) and 1 part in Java(which i will build) and then use them to build a sample website.
What level(kind) of difficulty it will accompany?

I am quite good with Java and have no experience whatsoever with C# or .NET.
Well then, do you have a particular desire to extend your knowledge into C# and .NET, or do you want to concentrate solely on the actual project.
People can make all sorts of arguments about C# vs Java, but in your case the pertinent facts are that C# will be much better at teaching you a new language, and Java will be much better at not requiring you to learn a new language.
Edit: Following the edit to the question, mixing the languages like you suggest as a possibility has the added advantage of needing you to show how to mix the use of two different languages, which might or might not be useful in itself.

Overall I would say that is is much easier to get started in Asp.NET. With Java EE, just setting a dev environment to do Hello World, can be a lot of work. In Asp.NET, you launch visual studio, create a project, and are ready to go. If you are using Netbeans and Glassfish, then Hello World is no longer a nightmare, but deployment is still a lot trickier.
Architecturally they are pretty similar, Java EE is a bit rustier, but has borrowed from many of the newer ideas of ASP.net.
Once you get up to speed in Java EE, it isn't that bad, so for a long term commercial project, it is a viable choice. For a short term student project it isn't worth the effort, and I would go with ASP.NET, but if I had a choice I wouldn't recommend either platform.
I would build my application in a dynamic language like python, ruby, or maybe groovy. The difference in productivity between static and dynamic languages is huge. Even if all 3 of your team members are new to the language I would expect you accomplish more in less time.
I would recommend looking into the following frameworks: django, pylons, rails, grails. I'm biased towards the python frameworks, but rails is also an excellent choice. Grails is a pretty cool clone of Rails written in groovy, but unless you have to have Java integration, I would stick with the other 3.

I am quite good with Java and have no experience whatsoever with C# or .NET.
If by that you mean you also have experience with building services and site, then use Java, no point in discussing it any further. The only possible reason is if You Want to learn .NET (a great reason imho though), but not at all because you should change to it.
Note that personally I prefer .NET vs. Java, but I would never / ever make a team experienced in Java change to .NET in the scenario you described.
If you do go with .NET, use ASP.NET MVC. It gets you closer to the right skills to learn regardless of the platform / HTML, CSS, JS, HTTP considerations, etc.

What if we implement 2 parts in
C#.net(which they will build) and 1
part in Java(which i will build) and
then use them to build a sample
website. What level(kind) of
difficulty it will accompany?
If the interface between these parts is a widely-accepted standard like SOAP or REST/JSON, then the language the individual components are developed in will matter very little - this is the whole point of such standards, and an important part of the SOA idea as well. I'd even consider such a heterogenous application a better example for what you're supposed to learn.
The only real downside will be that you'll have a harder time helping each other when you encounter problems.

Ill approach this idea by idea:
Platform: You are familiar with Java, I would recommend for the time being staying within Java for the time being.
J2EE do you mean Java EE? J2EE is quite old by today's standards.
There are not many, if any, fundamental differences between .NET and Java platform code. It comes down to a matter of preference and what Operating System you are primarily working on, imo. If it is only Windows development I would lean towards .NET, however if you need portability lean towards Java.
Also I wanted to point out SOA is more of a buzz word consultants use. You will see this as you gain experience in the industry. Cloud is the new SOA, this is purely opinion.

It may be worth your while to do the other components in something you don't know as having that experience could make you more marketable to industry. Look at job offers for a field you'd like to do work in. What experience are they asking for? Maybe use something they ask for as one of your components. I've never seen a job ad that asked solely for Java experience, it's usually accompanied by other technologies like scripting languages and framework experience.

From .NET to Delphi, an ERP on Delphi [closed]

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I have learned programming on .NET. It's been 4 years since I have started (serious) programming, I gained experience in VBA, JavaScript but mainly C#. I have spent a lot of time trying to grasp the good coding practices, object orientation etc.
Now finally I have a job. The job is fixing/upgrading an ERP on a daily basis. Creating reports and maybe sometimes new stuff. I have absolutely no experience in Delphi, and no motivation to learn it especially when people are moving to .NEt from Delphi not in the reverse direction sa my manager expects :)
The question is that are there any tools that I write C# code and compile into this object pascal or whatever it is. Thanks in advance.

If you can program, you can program in Delphi. It shares most common modern programming paradigms with languages like C#. If you can't quickly make the transition from C# to Delphi you need to invest some time learning general programming concepts.
If you're going to attempt to maintain a large system written in one language (any language, doesn't have to be Delphi) while refusing to understand the language the application is written in you are unlikely to be successful. Similarly, if you make a habit of posting about the crappy architecture of a system you've just been hired to support, and the technical incompetence of your manager, you're unlikely to hold onto any job for a long time. That's true even if the architecture is genuinely crappy and your manager is a genuine idiot.
Frankly, I can't understand how you got hired to maintain a large Delphi system without knowledge of Delphi, or why you chose to take the job when there must be many more jobs available that require C#

"I have absolutely no experience in
Delphi, and no motivation to learn it
[...] The question is that are there
any tools that I write C# code and
compile into this object pascal or
whatever it is."
LOL.
A good programmer /should/ be able to quickly adapt to different languages and tools when required.
Go overcome your prejudices and start learning Delphi.

Imho, such tools would make more harm than good. And this is because:
Fist of all because in some areas Delphi is more expressive language than C#. For example see here for a very quick glance. Note that on the above StackOverflow question, Delphi is by far the most upvoted answer. And the question sounds "What is your favorite language..."
Delphi is a language for high-performance applications. It produces much more performant executables compared with .NET. (for ex. see here and here for a very small (imho) collection). Having such a conversion tool will simply cut down all Delphi's power. Also, don't forget that Delphi has explicit memory management.
Of course, there is all the maintenance problems: bug-fixing, GUI consistency etc.
Also, about everyone (and everything) is going from Delphi to .NET I humbly think that you're a little bit off here. Of course (as you say) you don't have experience with Delphi (not a bad thing per se), but believe me, here on StackOverflow and also on Delphi's forums (at Embarcadero's site and elsewhere) there are a plethora of new users of Delphi. It is easy to spot them from their questions.
Also, in order to be constructive, I recommend you, in order to get started, have a look at Delphi's Wiki which is a good portal which gather more or less enough interesting links for the newcomers. There's also Delphi Basics which is a very good resource to start with.
But first of all there are Delphi's newsgroups, which is an invaluable resource of information - feel free to post there and also here on StackOverflow. Beware, on Delphi's forums you'll have the best experience using an NTTP newsreader.
Also, if you want to have two-way communications between Delphi and managed code you can have a look here and here. Also you can work with .NET assemblies "directly" (eg. by using COM) - but believe me, do it only if it is really necessary, because your very small (I mean exe size) and fast application most probably will became slower and will depend of a big runtime - thing which is very bad if your app is sold as a shrinkwrap software. But, of course, there are scenarios in which .NET dependency won't hurt.
FTR, we have an ERP developed in Delphi which is in production from 9 (nine) years now and is continuously updated. However we don't think any moment to change our development tool, even if we could do that with ease. But of course, YMMV.

I'm a former Delphi developer who now works primarily in .NET/C#.
It is straightforward to write maintainable, well-designed code in Delphi. It's a strongly-typed OO language. While some Delphi developers have a RAD mentality (code under buttons), you can do that in C#, too. Model-View-Controller and its variants are certainly possible. You can even be test-driven with DUnit.
If you are using a .NET version of Delphi, there's a Reflector add-in for the Delphi language. This would let you write C# code, compile it to IL, and disassemble it in Delphi. That's probably not practical for large-scale development, but might be a learning aid.
For older (Win32) versions of Delphi, you have fewer options. You'll need to learn Delphi or find another job. Really, the main thing you lose over .NET/Java is garbage collection. If you think of every object as implementing IDisposable, though, it's not hard. Alternately you could use reference-counted interfaces, but I wouldn't recommend that for every class. The main learning curve is going to be the VCL, which has many similarities to the .NET FCL.
Good developers generally know multiple languages. Treat it as a learning experience.

You can convert C# code to Oxygen (=Delphi Prism = almost Delphi):
http://code.remobjects.com/p/csharptoxy/downloads/

That people is migrating to .NET does not mean that .NET is the best for all projects. You should look at the needs of each particular system.
I'm sure that some will be better .NET and Delphi will be more optimal for others.
Read this article please.
Ragards.

You probably recognize the following pattern:
Developer1 creates AppX, works on it for years. Developer1 gets bored or decides he can make more money somewhere else. Of course without leaving documentation. Good for him.
Now we enter this loop:
AppX needs to be maintained, so a new developer (DeveloperX) gets hired;
DeveloperX doesn't understand the code or the workings of AppX;
DeveloperX convinces his manager that it's better to rewrite (preferably using some "cool" technology);
DeveloperX fails to "get things done";
DeveloperX gets fired or quits;
Go back to 1.
Emray is currently between step 2 and 3.
Anyway, I conclude that the application is in danger.
I've personally seen many Emray's come and go over the years. Wants to work with cool new technologies but doesn't have experience or the drive to actually learn stuff unless it looks cool on their CV.
There will be people like us who have to clean up the mess after him.

I'm sure you have to learn Delphi to do successfully that job.
For example simple bugfixes will have to be done in the Delphi.
Also user interface should be consistent over the product. So it should be created in Delphi. Even for new features.
Sure also there are possibilities to call external code from a Delphi code.
Options might be DLLs or as WebService.
And that external code could be done in .Net.

I'm now working mainly with C# but for years I wrote Delphi applications. The Delphi IDE was way ahead of it's time for many years. I stopped working with it with D7. I didn't like D8 and now that they have prism. You may be able to port the Delphi code to Delphi.net. Then you could convert it to C#. Probably need to ask the manager first though! :)
Delphi is an easy to learn language. You should be great at it within a few months. Learn Delphi. Here's a few of the standard books for Delphi
Mastering Delphi 2005
Delphi 2009

You could try to learn by doing: just choose an Open Source projet written an Delphi and have fun :)
In your case, an open source ERP would be perfect : OpenGestionale for instance is an italian ERP developed in Delphi (2007).

First, I will say upfront that unwillingness to learn an unfamiliar language is not a good enough reason to attempt what I'm about to describe.
The original poster's lack of enthusiasm for Delphi not withstanding, there are program transformation tools that can be useful for project migration, re-engineering or even on-the-fly language translation. (this is certainly not their only use)
http://www.program-transformation.org/ has a wealth of information of the subject. Semantic Designs is one of the more well known commercial developers of program transformation tools. They do have a selection of tools for translating C# into other languages.
Note
These kinds of tools are complex and have a high learning curve (a lot higher than learning Delphi to be sure) but are tremendously powerful. The commercial tools are also a bit expensive. A developer using these tools needs a thorough understanding of both the source and target languages you intend to use.

Learning Python for a .NET developer [closed]

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I have been doing active development in C# for several years now. I primarily build enterprise application and in house frameworks on the .NET stack.
I've never had the need to use any other mainstream high level languages besides C# for my tasks, since .NET is the standard platform we use.
There are some legacy Python applications that I have been asked to support going forward, I have no exposure to python and dynamic languages in general(although I've done a fair bit of JavaScript).
I was hoping to get some guidance/advise to aid in how to go about learning a language like python for the statically typed mind.
EDIT: Using IronPython is not an option!

Foord and Muirhead's IronPython in Action is an amazingly good book, perfectly suitable for teaching Python to .NET folks as well as teaching .NET to Python folks. I may be biased, as I was a tech reviewer and Foord is a friend, but I've had other cases in the past where a friend wrote a book and I tech reviewed it -- and ended up deciding the book was just wrong and publicly saying so (way to lose friends, but, I just can't tell a lie, not where Python is concerned at least!-)
Edit: If you're forbidden from moving to IronPython (which would probably support your legacy apps just fine, btw), there are better answers: Mark Pilgrim's Dive into Python is often considered the best Python intro for the experienced developer, and my own Python in a Nutshell has been praised as the fastest way onboard for superstar developers. I am of course biased in favor of these -- Mark is a colleague, and my wife was a key tech editor for his book (and my own as well), and obviously I'm biased in favor of my own book too;-). But then, I do tend to be biased towards a lot of the best Python books, as I've either had a hand in their editing, or am friends with their authors, or both;-).

Hardest thing I was confronted to in using python coming from Java was to properly wrap my head around the Duck Typing thing... At first I thought it was just plain horrible and just dressed the hairs on the back on my neck.
Next is the scope by convention, but that one is pretty easy. And the importance of white spaces gave me a few bumps.
However once you ease yourself in the language's concision and speed of development you learn to appreciate it a lot more. After a while I thought it was the best thing that ever happened to me !! :-)
here are a few things that helped me a lot :
First I started with this book and got the basics of the language and for everyday use the Python Quick Reference Card was very helpful. Also the console will be your best ally to try quick things and solidify your learning.
For IDEs, coming from the eclipse world PyDev was a natural choice for me, but there were many more to choose from. But if you are more familiar to the Visual Studio environment the Python Tools for Visual Studio is pretty darn good too.
Good luck, Hopefully you'll find Python as much fun as I did.

There is a big initial hurdle of getting comfortable with dynamic typing. The first step is when you look at Python-code and realize that variables aren't defined anywhere, you just create them out of thin air, which feels like jumping over a cliff. There is a brief moment before your hang glider catches the air properly.
And then it's going to take time before you trust your newfound dynamic wings, and you probably only can get their by doing aerobatics with them. Learn how python handles references, have fun with monkey-patching methods, duck type various animals. Try to learn some ugly tricks.
And although you can't use IronPython for this, there is no reason you can't use it to learn Python.

You're going to experience quite a bit of culture-shock going from C# to the wild duck-typed outback of Python. Lack of types and intellisense can be pretty daunting. Good thing that you're experienced in JavaScript. Also know that indent-sensitive block rules of Python can be very confusing for the inexperience (usually you either love it or hate it :-)
Apart from that the biggest challenge moving from one language to another is usually the framework. Getting to know all the classes and functions Just Takes Time unfortunately.

For an experienced developer learning Python, Dive Into Python is a very good book.
Wesley Chun's Core Python Programming book takes a more "ground up" approach, which may be a little slow for an experienced developer. But it allowed for very easy comparisons of the basic syntax and operators compared to other languages. Wesley's writing style is very easy to read, and his example projects are non-trivial enough to actually be interesting.
The Python Cookbook is an excellent reference for learning to program in a 'Pythonic' way. This book contains hundreds (?) of examples of how to solve common everyday problems with Python. In general, the "Cookbook" series will expose you to the idioms of the language faster than any other book.
Whenever I need to learn a new programming language, I start using it for all the 'daily maintenance' tasks that come up - all the little things that I would normally solve with a shell script or with common unix tools - I start to use the new language to solve those problems. Since you have .NET experience, IronPython is probably a good way to leverage that knowledge while learning Python. Even if you only install IronPython in a personal sandbox...and use it for all your daily busy work coding tasks - that can be a great way to learn the syntax and idioms of Python.

The book Pro IronPython is worth reading too if you have time.

I would recommend just to read a book about it. A book for beginners. It'll contain many stuff you already know but you won't miss anything regarding using a dynamic language. I can point you to Dive into Python, which seems to be very friendly, or The Python Tutorial which seems to be very to the point (that's how I learned).

I would recommend using IronPython to help you learn. It is an implementation of Python on the .NET framework. So you can use/learn Python with access to the .NET class library.
A good place to start is by downloading IronPython and looking at IronPython in Action, which is a very good book looking at Python on the .NET framework.
EDIT: Since IronPython is not an option, disregard this answer. Thanks though.

C++ or Python for C# programmer? [closed]

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I am a corporate C# programmer. I found some time to invest into myself and stumbed upon a dilemma. Where to go from now? C#/.NET is easy to learn, develop for, etc. In future I would want to apply to Microsoft or Google, and want to invest spare time wisely, so what I will learn will flourish in future.
So: Python or C++ for a C# programmer? I am a little scared of C++ because developing anything in it takes ages. Python is easy, but I take it as a child-play language, which still need lots of patching to be some mature development tool/language.
Any C# developers having same dilemma?

I Am a little scared of C++ because developing anything in it takes ages.
I'm not sure how you can say that when you say yourself that you have no experience in the language. C++ is a good tool for some things, Python is good for other things. What you want to do should be driving this decision, not the technology in and of itself.
C# programmer or not, I would assume that you can pick up any language, but a language is just a tool, so your question is difficult to answer.

Python may be easier to get started with, but a dynamically typed scripting language is a very different language from C# or C++. You will learn more about programming learning it than you will by hopping to a close cousin of a language you already know. Really, solid familiarity with at least one scripting language (Python, Perl and Ruby are the favorites) should be a requirement for all programmers.

If you want to apply to Google then Python might be the one to go for, surely MS would like the C# already. If nothing else the competition would not be as fierce as there are much more folk out there with multi years of C++ experience. Also Python gives you a broader language skill and would be a good path to more languages and scripting.
But as said and will be said again, choose your tool wisely and see whether it's a nail or a screw you're trying to secure.

C# is a little closer to Java and C++ than it is to Python, so learn Python first out of the two.
However, my advice would be:
Stick with your current language and learn more techniques, such as a wider range of algorithms, functional programming, design by contract, unit testing, OOAD, etc.
learn C (focus on figuring out pointers, multi-dimensional arrays, data structures like linked lists, and resource management like memory allocation/deallocation, file handles, etc)
learn Assembly (on a modern platform with a flat memory architecture, but doing low-level stuff like talking to hardware or drawing on a canvas)
learn Python or Ruby. Chances are, you'll stick with one of these for a while, knowing all of the above, unless some hot new language has come along by then.

Why not learn some of each. Studying a language for a week or so won't make you an expert, but it will answer a lot of questions in your head and plant a seed for the future.
It's important to not just read through exercises. Find some simple problems that can be programmed in a page or two at most and solve them with each language. That will help you to learn the strengths and weaknesses in the context of the way you think and how you solve problems.

C++ is usually used when speed, and low-level OS access is involved.
It's a good skill to have if you want to expand.
Python allows you to do thing quickly, and it's quite easy to learn, and provides more power than you'd expect from a scripting language, and probably one of the fastest ones out there.
C++ isn't exactly slow to develop, if you've got an IDE, it's not hard to write per-se, but the syntax is going to get you.

If you want to apply to Google and/ or Microsoft then I'd say that of the two you need both!
Given more choice, probably C++ and one other language - either dynamic, functional, or both (Scala might be a good choice too).
It's not necessarily about whether you'd use the languages themselves but more about the different approaches they require and encourage.
If you continue to be "scared" by C++ you're probably going to struggle applying as a dev at either of those organisations - unless you are highly specialised elsewhere.

I think you just asked wrong question. It is not about the tool itself. It should be about what kind of software do you really find enjoying to create. C++ is used in creating different types of applications that are written in C# or Python. Please mind, that C# or .NET itself is not easy to learn. It may be quite easy to develop something that works somehow, but if you just delve into the details...
Anyway, my point is: if you're interested in developing web solutions: go for Python. There is a lot of hype about Python at the moment, and even Microsoft realized the power of this language (you may use your knowledge of .NET and Python programming using IronPython).
C++ is at the moment used in some specific areas. Business apps are written mostly in Java or .NET, and C++ is still great for more low level programming, in areas where performance is the crucial thing (and I mean 'performance' as performance of language/platform itself). The good example is game industry: Java and C# are definitely easier to learn than C++, but... how many 'big games' have been created entirely in C#/Java?
I have another advice for you: if you want to work for Microsoft or Google, do not focus on language itselft. It is NOT the most important thing. Focus on problem solving, algorithms and other stuff (Stevie Yegge's post about how to prepare for an interview at Google).
Oh, and of course as a fan of C++ (and C# too) I must admit that it is not true, that developing anything in C++ takes ages. You probably think of C++ as of "C with clasees" - take a look at STL, templates, advanced templates, Boost... Somehow all those people working in games industry manage to create better and better games in not so looooong time that takes others to create 'boring and easy' business app in Java/C#.

You might be interested in looking at Windows Powershell. It's the latest scripting technology from Microsoft, built on .NET, and can be extended via C#.
Granted, it's not as portable as C++ or Python, but it would leverage your C#/.NET experience more readily. Otherwise, I would suggest C++ (and possibly C). Microsoft builds a lot more of its products with C/C++ than with Python.

As someone familiar with C# and .NET you should consider IronPython. Python for .NET. This would be a good way to leverage what you know and learn a new dynamic language at the same time.

Why should I learn C#? [closed]

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I want to know why I should learn C#?
What features does C# have that Java does not?

C# is an object-oriented high-level language which can be useful to develop applications.
It supports getter/setter constructs, delegates and true generics, which Java does not.
C# usually feels more "native" on Windows, since Windows.Forms and WPF are closer to native code than Swing.
However, Java is more cross-platform than C#(even though project "Mono" is changing that)

There's a whole lot of differences: http://en.wikipedia.org/wiki/Comparison_of_C_Sharp_and_Java
Whether you should use one over the other depends on your priorities. What do you want to write in them?

C# (and other the CLR languages) have aspects of functional programming (such as delegates and closures) that make some types of development and design patterns easier. See this post by Steve Yegge for more. Delegates can make code much more expressive and concise.

You should learn both, and use each of them as appropriate. I don't feel like it's a "which one should I learn?" kind of question. (Or a "I know Java, why should I learn C#?" question.) That comparison that Welbog posted will help you decide when to use one over the other. But, myself, I like having both in my toolkit.

Syntax:
They are both reasonable languages--they support pretty much the same high level structures and designs (OO, encapsulation, ...) and are fairly equal up until you get down to the code level (which overall isn't that big a deal. C# beats java in features, Java beats C# in simplicity I guess).
Portability:
My biggest factor has been that lately I've worked on apps for a spectrum analyzer and upcoming cable systems. Neither would have been remotely programmable in C# (you are completely reliant on microsoft to port the runtime to your platform of interest. Java is open source (there may still be one or two little pieces that aren't, but they are sincerely working on that and it's enough that you can port it and use it just about anywhere.
If you are only ever interested in Windows and if you'd like to take advantage of tight, simple integration with windows, then C# is the platform for you.
VM
Both languages include a "Runtime" that can support other languages--and those other languages generally have access to the (very rich) libraries provided in each environment.
Microsoft can run a few (a dozen) languages on it's VM, none as impressive as C# (although Ruby and Python could be good--are they fully available yet)?
The JVM has a few hundred including some cutting-edge experimental languages that often run as well as or better than their native counterparts. Some are considered the next generation in programming, as different from Java/C# as they were from C. I looked into Scala, but I must be getting old, it just hurt my head, but I admit there are some very advanced concepts available in there. Groovy rocks.
System integration/tools:
C# wins hands down since Java can't commit to any one platform. C# is also very well integrated with databases and other external dependencies, Java is getting better integrated, but the tools are a little more mismatched. C# the entire toolset tends to be very integrated since it all tends to come from a single vendor.
Number of platforms using it (number of potential customers):
Last I heard, Java wins hands down. WAY down. Every try to figure out how many phones, microwaves, TVs and toasters might be running Java? The number dwarfs every other language combined as I understand it...

the only reason you should is because you want to
C# is a
multi-paradigm programming language that encompasses functional, imperative, generic, object-oriented (class-based), and component-oriented programming disciplines
so you get to learn a lot of tricks from different paradigms, all in a single language

There are lots of questions that people have asked on this topic already. Read up, they've got good infos there. :)

The biggest reason, imho, why is because (for windows desktop apps at least) Java UI is godawful ugly. Fugly ugly. Vomitously ugly. Ugly like the kid you'd have if you impregnated your sister.
If you are required to run on any OS, Java is your best option (tho Mono is catching up!). But if you're programming for the Windows environment, C# is a dream to code and looks like any other native application.
Other than that, I'd say Linq. And the ability to fail fast on exceptions rather than having to handle exceptions everywhere (like we actually know how to handle each and every exception). Oh, and Linq again. Linq is so beautiful... to me... Can't you see?
Crap, forgot about lambdas. Damn, I love lambdas and all their closure goodness.

Simple answer -- C# is the primary language for developing Micorosft applications at this point. Learning it opens up a new world of potential opportunities to work on Microsoft-based applications.
Also, it's not really that hard to learn. Just a little harder than VB was, but with lots of OO power.
Some people would say C# is Microsoft's Java -- actually they look almost identical, just minor differences but different class libraries. If you already know Java, picking up C# shouldn't be too hard.

I can't believe nobody has posted this yet..
Because, it is a fun language. Personally I think Java is a rather nasty language (still can be fun), but not as enjoyable as C#.

Do you need to learn C#?
Is your job situation going to improve?
Do you want to learn something new?
Is the development environment better in C#, is the tooling better?
Do you think you can do something in C#, that you can't do in Java?
Maybe a generic language for desktop, web and mobile - but Java has this as well.
Just a few questions you could use to decide.
I'm C# myself, started out in Java when I was introduced to programming. I think Java did a fantastic job for me in understanding programming, mostly because there were no magic IntelliSense, or form designer for Windows apps - we had to write the whole damn thing our selves. Which was good, when you're learning. But I think C# and the whole .NET/Visual Studio eco-system enables you to be more productive.

More important than the feature of the language are the run-time environment and the libraries.
C# and Java have a different set of libraries, frameworks, operating system interactions, etc.

Based on the question seems like you are not interested in learning it for the sake of knowing more about programming and clearly looking for practical reasons.
That is why I don't think you should bother learning it, since it will be just another tool to accomplish same thing in your toolbox.

I like what Welbog wrote. I would add that it would also depend on where you're at professionally, your interests, and your job prospects /interests.
If you're you've just started to learn Java, then picking up a little C# might help in terms of broadening your programming horizons. The languages are similar (roughly speaking), but of course there are nuances to say the least in programming in one versus another. If you've been programming Java for awhile, then perhaps you'd be better off either expanding your J2EE area of expertise or maybe looking at other supporting areas and/or languages.
In terms of job prospects, you might find companies in your area hire more .NET developers than Java, or vice-versa. You might also want to look at companies you want to work for and make sure your skill set matches. For example, if you've dreamed at working at a particular firm who uses JSP, just as an example, then sticking with Java would be better.

It is not C# that you should want to learn but .NET Framework and related technologies.
Think rather J2EE vs .NET.
Why would you want to learn .NET? It's up to you to decide. Like Java it's one of the few major development platforms. It is functional, very actively developed and supported with a huge community knowledge base.

To me the choice is as simple as I need to use .NET libraries, so I'll use C# or I need to use Java libraries so I'll use Java. If I'm working on something on a Windows client I'll use C#, if I'm working on something that needs to run against the P6 Integration API I'll use Java.
You shouldn't feel like you you are missing something or should use one or the other. Look at what you have to do and pick the best tool for doing that.
It's tough to list on a post here all the features of the .NET Framework, just like it would be tough to list all the features contained in the Java SDK Libraries.

Learning C# because it may or may not have features that Java doesn't have seems like a very odd reason in opinion (it does have a number of features, that Java doesn't but so does F#, LISP, Haskel, Ruby, Lua and even COBOL).
You should learn C# because
You need to (to keep or get a job, stay in school, whatever)
You want to
It is fun to expand your horizon
Any or all of the above

There are some syntactic sugar advantages in .NET such as LINQ or Properties. (Yes, you don't have properties - not to mention auto-properties - in Java).

Strategically, it helps to know several languages as demonstrated by a little research. Currently, PHP, Java, and ASP.NET (C#) are the most widely used server-side programming technologies (see https://w3techs.com/technologies/overview/programming_language/all). Therefore, knowing all three empowers your backend engineering potential.