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Closed 12 years ago.
over the years i have been employed in a permanent position with firms that did their development work in Windows SDK, VC++, and most recently Java; in my own eyes, I am language independent.
Should I move from Java to Delphi (assuming pay-scale remains unchanged)?
I'm concerned because, for the most part, the net presents a relatively bleak picture for this particular skill.
The TIOBE Index is an often cited source for estimating the popularity of programming languages. Java, C and C++ have been the top 3 for a very long time. As you can see, Delphi is a lot lower on the list (at position 10 at this moment). (Ofcourse you should not take the TIOBE Index as an absolute measure, but it does indicate something).
This can be an advantage as well as a disadvantage. There are probably a lot more Java and C++ jobs than there are Delphi jobs, but there are also a lot more Java and C++ programmers than Delphi programmers, so it's harder to stand out as a Java or C++ programmer among the masses. Having a specialism that not many people have, such as for example Delphi, may help you get a higher salary, though you'll have to search harder to find Delphi jobs.
Depends on what your goals are, but I believe that for regular apps the future bears name "GWT", i.e. Java. (I consider Delphi a history for quite a while, but that's JMO.)
It's definitely worth learning Delphi. A lot of software's still being written in it, stuff which people use and rely on. A lot of companies prefer to keep quiet about it, though, since it presents such a major competitive advantage over other, more popular languages.
For example, you ever work with VOIP on chat programs? In my experience, there are two basic categories: Skype, and The Other Stuff. Skype "just works", while the others tend to be very glitchy and unreliable. And it's no coincidence that Skype's written in Delphi while (AFAIK) none of the other chat programs are. That's just one example among many.
It never hurts to pick up another skill, but I haven't seen any Delphi job listings anywhere. I suspect you would be better suited picking up a new language/framework/platform with more "legs", such as WPF, JavaFX, Objective-C/Cocoa, ActionScript/Flex, or something of the like.
As a technical move, it's probably a good one -- Delphi is better thought out and more enjoyable to use. From a career perspective, however, you're probably right -- Delphi has been rather marginalized for some time now, and doesn't seem to be in the process of making a huge comeback.
I was using Delphi before I swtiched to C++ and then to Java. I don't think that moving from Java to Delphi is wise idea. Why so?
Java is widely used
It's easier to find Java job
More years of Java -> Better chance getting senior position job (java oriented)
Java is definitelly richer as for libraries
Java rocks in enterprise sphere, Delphi doesn't
It's easier to find resources for Java - from tutorials for beginners to manuals for professionals
Java runs on other operating systems by default, remember? (I know Lazarus, but can't compare port to nativeness)
From my exprience, more experienced programmers and software engineers kind of condemn Delphi programmers ...
Java is suitable for larger projects (means bigger money)
The only good reason for preferring Delphi over Java I can actually think of is making Windows GUI application. But since we have .NET and wonderful WPF, Delphi doesn't score even here.
You make your choice, but personally, I'd never switch back to Delphi (ok maybe if payment was too good to reject:))
The way you phrase your question makes me think you've got a job offer already for a Delphi developer position. If the language is the only thing stopping you, I say you should go for it.
It will add experience with another language to your resume besides being fun (learning something new). Just make sure you keep your skills in Java and C++ reasonably up to date when or if you need to move on.
Why limit yourself to one language?
A major problem with Delphi is that some people consider it an "easy" language. So there are Delphi programmers that can drag some controls to a form without any real coding knowledge. So if you are a good developer and skilled in Delphi, you won't have that much trouble finding a job.
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Closed 10 years ago.
I've been doing web application development for the last 3 years in PHP. I'm now on the verge to give Java a go. My last use of the language was nearly 8 years ago and was mostly academic.
I'm reasonably well acquainted with PHP's object model (version 5) and I have almost exclusively been coding in OO. I would now like to transport that experience and use it to develop in Java.
Where I'm coming from:
linux as a desktop and server
Vim/gVim + plugins as an editor
MySql for db
apache httpd
experience with a bunch of PHP frameworks, Zend+Doctrine being the ones I use most
What I've garnered so far about a move to Java:
I need an IDE: IntellijIDEA, NetBeans or Eclipse
I need to pick a development framework. Some recurrent names: Spring MVC, stripes, wicket.
Now I need some insight that could help make this transition smoother. But from the way people talk about it, Java seems to be an entirely new beast with its own ecosystem. It sounds as though moving to Ruby or Python would actually be easier, which is curious since, when I look at it, Java conceptually seems the closest to PHP, albeit stricter and precompiled.
As weird as this may sound, very few people have publicly documented their experience of such moves. I have searched google, amazon and stackoverflow for similar questions and the results leave to desire. I just can't believe that I would need to start the same as a newbie if I wanted to be productive as a web developer in Java fast.
Anybody is welcome to respond, but I somewhat think that people with some valuable experience in both languages would enrich this discussion the most.
What helped you get going quickly in Java?
What concepts are omnipresent in Java and absent from PHP and vice versa?
Some gotchas for PHP developers going Java.
How long before you felt the transition was complete?
I wouldn't try to learn an IDE at the same time as learning a language. An easier transition would be to stick to your shell and habitual text editor, and use the following shell-friendly tools:
ant, for organising your project, running automated test suites, incremental compiles
BeanShell for interactive testing, trying things out quickly
A quick trick: javap from the commandline will give method signatures for any class in the standard library. Similar to php -r but gives more information since Java is typed.
The online documentation for Java is precise, professional, and consistent in tone and format. Unlike in PHP where all of the functions are in one flat namespace, the standard libraries in Java are class hierarchies. You've got to know your way around that standard library, which means knowing hierarchies + responsibilities: for example you've got to know that java.util.List is a subinterface of java.util.Collection with the addition of a concept of ordered entries. With that information in your head, a google search for java.util.List will take you to the Javadoc for the class, and the Javadoc will tell you exact method signatures and link you to a selection of concrete implementations.
Some miscellaneous distinctions:
Strings are sequences of characters rather than sequences of bytes. Absolutely the right way of doing it.
Systems produce and consume streams (of bytes or characters) rather than byte buffers. For example, if you wanted to filter the output in PHP, a standard practice is to ask ob_get_contents for a byte buffer then to transform the whole buffer. In Java, you add a filter to your servlet that transforms the output a byte or a character at a time. It's a bit imposing to work with initially but it's simpler and more Lego-like when you get used to it - your stream processor doesn't have to know where things come from and where they go.
Almost everything useful is an interface, and creating an instance of an interface can be tricky, non-standardised, and not always well-documented. In PHP, you can get up and running with XML with new DOMDocument(). In Java, org.w3c.dom.Document is an interface, so new() won't work. Javadoc is very precise about how interface instances behave once they come into existence, but it can be quite coy and prudish when you're trying to find out how an object is actually born. Very often, you'll have to look for tutorials and code examples and copy-paste a piece of boilerplate that gives you an instance of DOMDocument or java.sql.Connection or whatever. One reason frameworks like Spring are popular is that they separate out the ugly object-creation code and present you with a world where interface implementations are just magically there.
I actually switched in the opposite direction. I found that Java works very well in a large company where you might be working on a single component, handing it off to someone else who integrates that component into a larger system, which is then packaged and handed off to a separate operations team - that's where all this indirection and configurability (FactoryBuilderFactory type abstractions, web.xml files, etc) makes sense and does something useful. In a small company where the programmers are the ops personnel, Java is a lot more work. With Java, you'll have to get used to concepts like starting up the Java process, monitoring the Java process to make sure it stays up, monitoring the Java process to make sure that it doesn't go into a coma where it's alive but not responding, shutting down and restarting the Java process with minimal disruption when you're updating code, etc, etc. If you have separate ops personnel, that's fine, it's their job, they're very good at it. If you're a programmer, babysitting a Java process can be distracting and difficult to do well.
Start with the Java Tutorial
http://java.sun.com/docs/books/tutorial/getStarted/index.html
Then go buy Head First Java
http://oreilly.com/catalog/9780596004651
It will get you going pretty quickly in the language which is essential regardless of what you want to do.
Strictly speaking, you don't need an IDE to work in Java. I've been coding heavily in Java for well over a decade (and heavily on other stuff for over 25 years), and I don't much like IDEs. Perhaps that implicit indicator of my age is part of the issue :-) It's a trade-off, like anything else.
I'll plug Stripes as a nice simple framework, but mostly that's because it's relatively small and limited in scope. The large frameworks like Spring are "kitchen sink" ecosystems, and learning Java with one of those frameworks may smooth some of the difficult parts but leave other basic aspects mysterious. Again, it's a matter of personal preference.
It's good to have somebody around who knows the language. Oh, and to that point, make a friend of the Java API documentation. As platforms go, the Java API has its ups and downs but for the most part the documentation is at least pretty thorough and pretty accurate.
You'll also want to get really familiar with JSP and its relationship to Java and Java web service architectures, because that'll be what you'll relate to your PHP experience most directly (I'd think).
The best move I made was from Java to PHP.
Beware of complexity. Primarily, the key to great software is simplicity, and that is why PHP combined with a good framework kills Java.
With Java, you risk becoming a slave to your servlet container and framework. Choose the simplest most flexible framework. Controls and custom tags are the devil. You'll waste days learning things that were designed to make development quicker, but are ultimately too complex and inflexible. Java will slow development due to: complexity, compilation, and static types. You'll come to loathe null pointer exceptions.
Edit: Tools aside, Java and PHP are very similarly structured "C" style languages. Much more so than Python or Ruby. It is the static typing and complex tools that make Java so foreign.
I recommend hitting up JavaBat at here
It will give you some good ideas. It took me 1 solid year in a professional setting to get a very firm grasp on Java and I have been able to move into other OO languages quite easily once I had the thoughts beaten into me.
This appears to be a bit of an old post, but hey...
I moved from C# to Java and I've just started a role and am moving from Java to PHP...
First off: Java is awesome :)
for your IDE get Eclipse, once you get used to it, you never have to leave the IDE (apart from SQL bits). It manages projects really well, you can download alsorts of plugins, such as SVN plugins. It allows you to run a Tomcat server within Eclipse and it will output errors straight to the Eclipse console.
for the framework, I used Struts and Tiles and Torque for the ORM, took me a while to get my head around them, but once we made friends, I can't imagine any other way of developing. Although I imagine for a small project it would be a lot of overhead!
agreed with an above post - get HEADFIRST JAVA, thats how I learnt and I used it for lots of other languages, they have a visual method of learning thats alot easier than pure textbooks - well for me anyway. I was up and running with in a day and confident within a couple of weeks I guess - but always learning :)
yip Java is strict, but you come to love it, for me moving to loose 'ol PHP is a bit wierd.
you will also need to download Tomcat to run your Java bits, its easy as to get running.
Java organises all your classes very nicely, none of this 'require_once(some_text_file.php)' rubbish, just 'import myClass' and off you go.
one of the things that annoys me is, there is no way of telling which JAR libraries you are NOT using, so after a couple of years working on a site, your lib folder can get a bit messy - specially if mulitple people are removing and adding functionality.
I could go on.
Paul
For my case, I only dealt with lot of procedural coding on the php, so jumping to Java, not only did I find everything to be more verbose and less forgiving than php (but now I know why it must be this way, and I love Java a lot) but learning to organizing my code in classes and also learning the eclipse IDE took about 1.5 years of just tinkering, trial & error, making stuff on my own (mainly swing applications).
I guess just creating stuff on your own, utilizing the vast amount of Java libraries out there to build your own stuff is fun is the fastest way. Also I think I could've saved more time by reading the java sun tutorials thoroughly. Even more time saving is making sure you've done a thorough search for libraries that prevent "reinventing the wheel".
Good luck!
A friend of mine uses in his company an ERP software written in PowerBuilder. Unfortunately the (one and only) developer is going into retirement soon. My friend really likes the software and wants to keep using it for at least ten more years, so my friend decided to buy the source code.
He wants to start a business to maintain the software and develop new features. At the moment there are probably about 50 installations of that software out in the wild and he already knows of a bunch of potential buyers.
Now he's searching for a developer and asked me... I did a little C/C++ programming, a bit of VB and a bunch of other languages but in the last years I earned my money by writing Java web applications.
From what I read, PowerBuilder looks quite antiquated to me, there are hardly any tutorials out there, no open source frameworks, awkward version control, didn't even read about any test frameworks. People here on StackOverflow say they hope, the language/IDE is dead. Additionally the code I'd maintain is completely undocumented and untested.
Do you think it's possible, for someone who never even heard of PowerBuilder before, to maintain such a software?
EDIT: okay, thanks for your answers. We decided to kick the old application completely and re-write it in an up-to-date-language.
Yes, it's possible. Powerbuilder is not a hard language to pick up, particularly if you have used VB already.
The Powerbuilder community is far smaller than what you may be used to with e.g. Java, but it does exist. The best place (other than SO!) to ask questions are the sybase.public.powerbuilder.* newsgroups.
For unit testing, try PowerUnit, and for source control, you can use Subversion via PBSCCProxy, TamTam SVN SCC, or PushOK SVN SCC proxy.
It's been a niche language for a long time now. In my opinion this is due the upfront cost of the tools required, which is essentially blocking anyone new from considering it.
The future is reasonably bright though: Sybase is flourishing, committed to PowerBuilder, and regularly announcing progress towards version 12, which will be a full .NET language like C# and VB.NET, and will ship with an IDE based on VisualStudio. You will be able to directly migrate your code to version 12, no rewrites required.
I started my career as a PowerBuilder developer, but quickly changed to java and python, as soon as I realized PB was almost a dead language.
Also, even if there are tools that can be used to apply programming "good practices", they are not widely known and somewhat expensive, so I've had to work even without version control (!!), left aside automated testing or continuous integration.
It is a language in which almost anyone can start to build usable apps in a short period of time and with little training, and the apps are built really fast, in contrast with java, that demands a period of learning until a developer can be productive, and even then, a webapp takes time to be developed.
But the payback is with maintenance, that quickly becomes a nightmare. Even a minor change in the database like a type change in a database column can destroy every datawindow (the PB ubiquitous data-access component) that refers to it.
It's pretty much similar to VB, in that as almost anyone can develop applications in it, with very little programming knowledge, the average quality of applications is very low, with unmanageable database coupling and plagued of bad coding practices.
My advice is not to build a Developer career in such kind of language unless the money justifies it, and in that case, continue training yourself in alternative technologies as a "plan b" to not become obsolete along with the language.
And always work to keep your coding and problem solving skills "in good shape" as this kind of language does not help in that.
Yes, any competent programmer, and even some not-so-competent ones can use PowerBuilder. However, I'd disagree somewhat with one of the earlier answers. It is different from pre-.Net VB in one sense: it supports true OO principles (encapsulation, inheritance, and inclusional polymorphism [but not operational polymorphism via Interfaces as in C# and Java]). Classic VB didn't have inheritance.
Other answers from Paul Lefebvre and Colin Pickard are correct: PB is still alive though more of a niche language than it used to be, and Sybase is indeed moving it in the direction of .Net. As for source control, PB supports some interfaces (we use it with VSS) but I'm thankful for Colin's nice set of links, which may come in handy in the future.
Frameworks: the most common one is the PowerBuilder Foundation Class, which Sybase open sourced years ago.
My caveat to you is this: I said above that people didn't have to be particularly strong programmers to write PB. PB is easy to learn but takes time to master. It had its biggest days in the late 90's, when anyone that could double-click on a Windows icon to launch an app thought they were a programmer. Despite truly supporting OO, most PB apps are not well designed and well written apps. They're usually total hack jobs (a criticism of the lack of experienced developers and immaturity of software development at the time, not of PB itself, which is still a very powerful tool). If you are inheriting a code base that is truly easy to maintain and manage, you are in the minority. PB code can nearly always be classified as legacy code. The good news is that there is plenty of challenge. You will have many quick-win refactoring opportunities and plenty of production support.
With the risk of sounding biased I think PB is one of the better RAD tools out there and the new version PB12 scheduled next year will make it once again interesting since it uses the VSShell from Visual studio as its new IDE (Intellisense etc). I am currently busy working in the compiler team adding all the .NET goodies to PowerScript that one is used to from C# like delegates, interfaces, attributes etc but still keeping the language simple to use. PB is also one of the few development platforms that provide migration from older to newer versions and the new PB12 is no exception. The applications generated by PB12 will be modern looking using WPF and later Silverlight for post PB12 so I am quite excited. I am not a PB developer per se (C++) but I still think for producing C/S apps fast its hard to beat.
It depends on the technical quality of the original application whether migrate to another language is feasible at all.
BEFORE YOU READ MY "PB IS GOOOD": I'm a PowerBuilder developer since '93. PowerBuilder is very much alive and kicking. Yes a lot of people left the language shortly after the millenium but quite a few have returned later. No I don't earn money selling PB!
The biggest differentiator between PowerBuilder applications and any other tool is the DataWindow technology. It is such a strong tool in the hands of an knowledgeable developer. Examples: Dynamic creation of optimal SQL for INSERT/UPDATE/DELETE. Close to every property of everything can be an expression using data in the DW buffers. DropDown DWs are so cool. DW and the rest of PB is truly DBMS independent!
How important is code completion when many of my DataWindows only need 4 function calls anyway?
Define DB connection >> dwData.SetTransObject(SQLCA)
Read all data from DB >> dwData.Retrieve()
Write data to DB >> dwData.Update(true, false)
Reset when committed >> dwData.ResetUpdate( )
My bet: If the original developers knew how to really exploit DataWindows - any estimates you make on migration to Java or C# will not even come close to what will actually happen. If they didn't: The application is just another application that does data binding differently than your new tool.
What you loose when using PowerBuilder? You need to accept that the 4GL and its VM are designed as they are - no access to the source code of the VM so you can't make your own VM customizations. No turning off the NULL support to increase speed. No changing the event order by rewriting the VM's event manager. 4GL means less lines of code. DataWindow means a lot less LOC. 4GL means less geaky bit tweaking.
/MicKr-
BTW: PocketBuilder is PB for Windows Mobile - cool idea!
Yes, you would certainly be able to learn PowerBuilder. Whether you want to is a question only you can answer, though.
I used PowerBuilder for many, many years (versions 4 through 9). There were parts I truly liked. It's a great way to build business applications. It's object-oriented and the DataWindow is a wonderful technology.
But it has its bad points as well. The IDE is archaic. The code editor is simplistic (no code completion, for example). Integration with source control is annoying and the community is pretty small. And it's Windows-only.
There is a magazine (PowerBuilder Developer's Journal - SYSCON), but it's pretty thin these days. Sybase does appear to have some neat things up their sleeves for future versions of PowerBuilder, however.
Personally, I liked it enough that I would go back to it if an opportunity arose.
I worked on powerbuilder quite sometime back, version 6.5
Its quite easy to use and one can compare it to VB.
I feel it would be quite easy to maintain an application and do small fixes and enhance the system.
There are quite a few companies that still use powerbuilder and maintain old application.
Powerbuilder is very easy, and you will find datawindows objects very helpfull to make reports, interfaces, forms, etc..
If you know visual basic, it will be easier
i learned powerbuilder in 2 months.
A disadvantage of powerbuilder is the cost per license.
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Closed 10 years ago.
I always hear that programmers try to pick the right tool for the job. I've never programmed in Java, so I was wondering What are its benefits? Why is it so popular? What should I use it for?
I just program recreationally. Is there anything about it that makes it particularly fun??
I think after 12 years or so, the "write once, run anywhere" mantra is almost true. Writing Java code pretty much isolates you from the platform dependent aspects of the systems on which you deploy it.
Portability
Incredible breadth of libraries
Bottom-up security
Performance
Robustness
Massive communities, the amount of help, libraries, IDE's, is huge (and thats a good thing).
For a casual programmer Java can teach a lot about object-oriented programming, and encourage good programming habits in general, without the need to worry about as many of the "messy" details (pointers, memory management) as, say, C++.
It's also a bit easier to debug "catastrophic" errors.
Java is really good at integration - there are specifications and implementations for integrating with many kinds of systems that you're likely to run into in an "enterprise" environment.
It's not really a "fun" language relative to popular high-level languages.
This seems to be getting healthy answers, but you might also want to look at "Why do people use Java?"
Java is a good language, but that is secondary to the importance of the standard library that comes with it. The jdk may not be the most elegant kit ever built, but it is extensive, powerful and reliable. Programming in Java the language is simple. Programming with appropriate reuse of the jdk is what it is all about.
Cross platform is in my opinion the most relevant benefit.
The main goal of Java was to create a programming language that could run anywhere. The target was GUI apps. This however never happen because the environment was too slow at the beginning ( now it has been improved ) but it prove true in the server side where the cost of development reduced a lot because the product development can be done in PCs and the deployment in very expensive hardware.
It brought easy of development also, because it was designed to have C++ like syntax but running on a virtual platform to avoid platform specific code. At first the penalty was the execution speed, because it was interpreted, but release after release the interpreters became more and more faster that even MS model its next generation of development after java and call it .net
Additionally You can have a read of the Java design goals here
I want to add one point: Java keeps a good compatibility to earlier versions. That means, your Java-projects are compile and run in most cases without any problem on newer versions. That seems to be a little point, but this stability in API's and language helps to build a big community around Java, including good tool-support.
Others already mentioned other important points:
good portability
lot's of libraries for nearly anything
easy debugging and easy to catch problems
There are only two reasons to use Java:
The Java Virtual Machine (Hotspot).
The huge amount of available libraries and tools.
There are other languages that run on the JVM and make better use of Java libraries than Java does, however.
After using Java for some time, I've come to the conclusion that it's fun to write in, limited in some very irritating ways, and it's performance is good though it seems that many programs are crippled by poor design.
I'm not sure if the latter is a function of Java, or an effect of Java.
In either case, in addition to all of the above stated benefits it's very useful for doing "net" related things. Treating resources with a simplified interface regardless of "where" the particular resource is, etc...
It is by no means a universal hammer.
oop provides like encypsilation ,inheritance,polymorphism not available in traditional programing .oop is closer to real life presentation of the programming
1. Relation ships can be representation using inheritance
2. Programme developement become easy due to increased modularity
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Closed 11 years ago.
Why would you choose java over others? Why did you choose java to program your application?
Please include what you are using java for (desktop application/ web application/ mobile).
Excellent tooling: IDE, CI, etc.
Vast array of 3rd party libraries.
Huge amount of documentation available.
Large pool of developers available.
Platform ubiquitous.
Excellent performance.
Excellent specification.
Sturdy garbage collection.
Managed memory.
Native threads.
Choice - implemented by multiple vendors.
I have used Java to build various middle-ware products: Inventory mgmt; CMS; chemical registration; etc.
One of the nice things about Java is that everyone knows it. Of course, now that I've said that, I'll get 80 comments from people claiming to have never learned the language. Be that as it may...
Like it or not, Java is the closest thing to a lingua franca (the idiom means "common language") we have in the industry today. Just about every has either used Java at some point, or (more commonly) is actively using it now. That sort of ubiquity can be extremely attractive to some companies, particularly those reliant on consultants. If you start a project in Java, you're pretty much guaranteed to be able to find talent to maintain the code base for years down the road.
On a different tack, Java is an excellent language for developing cross-platform desktop applications...it's just that nobody knows it. Most of Java's dominance is on the server side coupled with a little bit of love from the J2ME crowd. However, if you objectively consider Swing in Java 6uN, it's hard to find a better tool for the job. Don't get me wrong, I see that it has its flaws, but many of those have been fixed in recent releases. Most of the issue now is mindshare: everybody knows that Java is slow and ugly (neither of which is strictly true anymore). The other problem is that Swing is very much a cross-platform UI toolkit. This means that it is inherently much harder to create professional UIs in Swing than in Cocoa or even WinForms.
Finally, a really great reason to pick Java (as opposed to .NET or Objective-C) is the ecosystem. Other answers have mentioned libraries, which really deserve a significant spotlight; but I'm thinking specifically of the rising language diversity. If you write an application in Java today, you can seamlessly transition to Scala at any time. You also have the option to do scripting in Groovy or JRuby, not to mention taking advantage of the powerful concurrency abstractions in Clojure. Because of its portability and high-level nature, the JVM is increasingly the preferred target for language compilers and interpreters (even more than the CLR). Java is really at the center of that nexus, not really benefiting directly from the vast cloud of languages which swarm around it, but certainly deriving value from all of the interoperability, present and future.
My reasons for prefering Java over other programming languages at this time are:
price - it's free
performance - really fast these days thanks to the HotSpot JIT compiler
effectiveness - lots of power with rigorous features like type-safe, sand-boxed, etc.
OOP capability
very good, well-thought out exception handliing; C++ exceptions are the opposite!
portability - it runs on almost everything
tool availability - awesome IDEs like Eclipse & NetBeans are free, as are web servers like Tomcat and application servers (JBoss, Glassfish, Geronimo, etc.)
flexibility - does graphics, desktop GUIs, web user interfaces - all kinds of things in all kinds of runtime environments
aptness - many enterprise apps today have to support HTML, SQL, and XML - Java has good support for all of them built in and you can get third-party libraries for free that make this even easier/better
well-supported - Sun keeps adding improvements and fixing thing going one or two versions back
forward compatibility - unlike something like VB which undergoes wrenching change in its syntax every couple versions or so, Java's syntax and semantics seem about 99.9% upward compatible from version to version
I have been writing programs in Java for over a decade and I am pretty satisfied with it. I have used other languages for almost two decades before that. So I am not biased by describing the one thing I know - it is one of many languages I know intimately.
When upgrades to the JDK/JRE come out, I look the documentation over to see what is changed. Sun is good about telling/explaining this. I have never had an extremely rough time porting from one JDK to the next.
When I have switched from one OS to another as my main OS at home or at work, it has not caused a problem for the Java applications I write - or the tools I use, generally. The one exception is Borland JBuilder, which some Borland marketing or technical genius decided to frequently stop supporting. Eclipse and Netbeans run terrifically on the Mac and probably always will. I have used Java on:
MS-Windows 95, 98, NT4, 2000, XP
Sun Solaris/SunOS Unix
IBM AIX
Mac OS X
Linux
Motorola cell phones (MIDP, CLDC)
Palm Pilot PDA
Java VMs (virtual machines) are everywhere! They are in:
web browsers
cell phones
PDAs
desktop computers
web servers
application servers
I have written programs on all of these. All you have to do is get an IDE with the right plugins, get the API documentation for the target environment you want, and start programming.
The GUI programs I write actually do look & work correctly on different platforms! I cannot tell you how long other vendors promised to do and how often/long they have failed. Just look around, some still exist.
Sun promised this in Java 1.0 and they sort of delivered it with AWT. However, the abstract windowing toolkit used native GUI components and the differences between these components (which followed no unifying standard at all) were too great to get same/nice look/behavior on all platforms.
Sun delivered very well upon this portable GUI promise when the Swing GUI API was delivered a decade ago, back in December 1998.
1) Very good and free documentation
2) Very good developer commercial and free tools
3) good certification and training resources
4) good runtime and free tools
5) good profiling and monitoring tools
6) very good support options from various companies
7) very good open source community with huge amount of libraries
Things not yet mentioned:
Cross-platform Desktop Application, even with sophisticated GUI
bunch of tools
static typing (see GWT)
error messages at compile time
very clear error messages
Java provides a very rich API right out of the box and hands-down produces the most portable applications since there is a Java VM for almost every platform.
BTW: I haven't used Java since I left college since I work for a Microsoft shop, but I can't think of a single thing I can do in C# that I can't do in Java, whether it be enterprise applications, web applications, or desktop applications.
Portability is the key to java. I know that a program that i am coding will run on any system, there is no need to create different releases for different OS's.
Java also offers built in security, making the coding of the safe programs easier.
Java is fast, with clean code java is benchmarking in the same range as C++.
C# is the language that gets compared to java the most often. C# isn't as portable as java, and has very few features that java doesn't. This makes java much more attractive unless the program will ONLY be run on a single OS, in that case i might code it in C++.
I switched from years of C++ to Java because I was working on higher level stuff and needed the benefits of memory management, reflection, and sandboxed execution that I get with Java.
I have tried COM in the late nineties and could not touch it.
.NET looks promising and in many ways is now much better than Java. Unfortunately, being window-centric is a complete dealbreaker for me.
Another benefit is the awesome static analysis tools available e.g. FindBugs. These perform a lot of checking on your code above and beyond those performed by the compiler, and can help identify bugs and/or code smells before testing begins.
Lots of great reasons have already been mentioned. I'd like to add the political part. I trust Suns language a lot more than Microsoft alternatives. It's not because I hate Microsoft, it's just that Sun is going a direction with Java that I really like, and Microsoft is going a direction with .net etc. that I really don't like.
This is very subjective, I know. But to me it seems like Sun really want to create a great language, and try to make money somehow. While Microsoft seems more interested in making money by vendor lock-in and systems that looks great and feels great, but may not be as good as it looks in the long run.
So the way Microsoft is handling it right now, I don't even care about how good or bad it is, technically. I don't care, I'm not going to use it.
Java has everything I want from this kind of programming language, including all the boring political stuff most people just skip. I don't know about any other current language that has all that.
The main reason I use Java for most of my desktop app projects is for cross-platform compatibility. It's quite easy to make your app run on OS X, Windows, and Linux and look native on all platforms.
I use Java for our BPM platform and used Java in the past for enterprise web apps.
It depends on what you want to do. Considering language features, libraries available and IDE experience, I personally would choose C# over Java. C# 3.0 has many useful features that Java lacks, such as LINQ, Lambda expressions, etc. Some people prefer the huge library choice that is available for Java, but I think there are just too many ways of doing things. Java IDEs like Eclipse and NetBeans are getting better, but I think Visual Studio is still much easier to work with.
Of course,if you are not using Windows, you don't have much of a choice but to choose Java. Ruby and Python can be good options for things like utility apps and GUIs, including Web apps, but for enterprise apps that don't use Windows, Java is pretty much the only option.
Please don't follow blindly all java-entousiasts. Java has its own flaws. Java is great for rapid development, enterprise oriented stuff, and "high productivity" project (with the tons of projects, community,...).
And if one guy show me a benchmark highlighting how java code can be as optimal as C stuff doesn't mean the complete java solution is fast and lightweight.
Java will never find its way on some performance critical applications, like games, codecs, web browser. No major game software is developed in java, and not because the developper are not capable of writing one piece of Java code that has the same speed as C or C++, this is because the very limitations of the language involves that performance and memory consuption will never reach a good C/C++ code. Takes VisualStudio and Eclipse. Java is great for one stuff (productivity stuff, enterprise middleware), but if you want to write codecs, games, performance critical libraries, you'd better try knowing C.
But, one the other hand, you'll write the java code faster and safer, with C and C++ you're taking more risk (pointers!) and this takes usually more time.
And don't forget the joke "Write once, Debug everywhere", this is actually true. You have to deal with different JVM implementation nightmare with Java.
Other programming language have their interest, bash/python scripts for local scripts (repetitive action, fast and quick UI,...). Php or ruby for webapplication are very well deployed and documented on the web.
Using it for desktop applications.
Excellent IDEs available, wonderful API, "C-style" syntax makes it easy to pickup. Once the JVM starts, the performance is great.
Why would I choose Java - is it the most popular language out there right now? If not, it's gotta be damn close, so if I'm building a product I might choose this because it would be the easiest to hire developers for.
Why did I choose Java - because it's what I know best.
Why would I choose Java? If I happened to have a team of replaceable code monkeys developers that knew Java better than anything else, that is probably what I'd go with.