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I have some batch data-manipulation scripts which support a small business website.
The scripts are a "rat's nest" of Perl, Java, and Stored Procedures, which run on a scheduled basis to update data based on various sources and algorithms.
I want to get rid of the Perl so that I can at least take advantage of transaction management by containing the entire process in a JVM-managed database connection from start to finish.
Which of the various Java dynamic/scripting language should I leverage which will meet the following criteria:
Straightfoward to migrate Perl code by providing similar expressive power, I/O, regex's, etc.
Good IDE support, including code completion and debugging preferably in Eclipse
Easy to install. Preferably the entire scripting engine should be in a single jar file.
Not an orphaned technology. I want to pick something that will still be around in 5 years.
Of course - clean integration with the rest of the Java code that I already have.
I hope my criteria are clear enough that this does not get tagged as a subjective question.
For me this is definitely a programming question. I see all those languages as just "useful java libraries".
Thanks!
To be fair, Jython, JRuby, Groovy would all be good choices. They all have the decent IDE support, and the syntax is as expressive, and more succinct than Perl. (Python and Ruby both owe a debt to Perl in their conception, so porting from Perl isn't too much of a headache)
Of course, Beanshell and Javascript (in the form of Rhino) will be adequate too, although I'd say that both their syntaxes are less expressive.
Judging on current usage trends, I'd say Jython and then JRuby would probably be the two with the most general support / longevity, in relation to the others.
Really the choice comes down to your level with each of these languages, but of all of them I'd suggest you use Jython, but if your more comfortable with Ruby, JRuby.
I vote Jython since it can interact with existing Java code and it's got a strong support base. Not mention its Python which is easy to learn and use. Eclipse has pretty good support for syntax highlighting, debugging, and auto-complete. Finally the install is super easy since it's a stand alone folder (no real "install").
I'll admit bias since I have used the other tools you mentioned much less than I have Jython but I have not needed to since Jython has fit the needs so well.
I should say that that several benchmarks indicate that Groovy is wins in speed, compared to Jython and BeanShell. The test was performed using DMelt (http://jwork.org/dmelt) framework where you can jump from one language to another, calling same Java libraries.
I know the .Net framework very well and know where to find things ie: StreamReader, StreamWriter, Graphics, etc, and I know Java has similar things. The syntax is different but quite similar to c++ which I have a lot of native c++ experience. Therefore, what would you recomend as a good starting point for tutorials and such. Thanks
In my new job, I quickly found myself working on a common library in C++, C# and Java. I had no Java knowledge and yet found it pretty intuitive to make simple mods to the Java code - the general C# principle that there is a framework class/namespace for most things you want to do, appear to hold in Java.
The thing that bothers me is that this MO would not teach me tricks and improvements in Java that are specific to that language. That's where I would like to see other answers to this question lead.
In the meantime: http://en.wikipedia.org/wiki/Comparison_of_C_Sharp_and_Java
btw while I found C# and Java pretty congruent, I would not say the same about C++ vs Java.
If you work in eclipse/netbeans/intelliJ it may actually be a no-brainer. Guess at a class name, start typing it and hit ctrl-space (for eclipse, others vary). Regardless of which package it is in, it will find all the classes that match and list them for you faster than you could look them up anywhere else.
The other really nice thing to have on hand is the javadocs for the SDK you are working with--you can code effectively with nothing else. They are online (just search for JDK 6.0 or whatever version) or they can be downloaded from the same place you get the JDK.
The javadocs are your friend - once you figure out some of the main packages in java.*, it's easier to know where to look for specific classes / functionality.
Once you're writing some code, buy Effective Java - it's full of tips for the language, and is just a good programming book.
I've been using PHP all the time.
Any advice to taking on these two languages?
I would say it really depends if you're used to the way OOP (object oriented programming) works. If you're not familiar with this way of thinking I would definately go with the book "Objects First With Java". It might look really, really basic at first, and you might be able to skip the first chapter or two. But if you read it from chapter 2 or 3 or so and finish it, you should have a good amount of knowledge to start building applications.
It's a little hard to help here because I don't know your level of skill when it comes to OOP. :) I've been writing PHP for a long time and didn't know a thing about OOP until I read the above-mentioned book.
All the best,
Bo
The same way you learned PHP - read the documentation, write some code, compile or execute it, debug it. Repeat until you are good. But don't expect to master a language quickly - anyone can learn to write code in a given language, but it takes time and effort to actually write good, high quality, and idiomatic code in that language.
The way I learn new languages is to read the documentation and other people's source code. It really helps to see what is possible in the language, without having it all wrapped up in academic speak.
Books are also helpful, if you have the time/patience to read through them.
A really good idea is to look up programs written in those languages and see if you can write the pseudo code for the programs. Then compare those to the source code and see what the difference is.
The best way to learn Ruby and/or Java is to forget the "PHP way" and to tackle each new language under their own idioms.
Both Ruby and Java have a fair selection of books (dead tree, electronic, free and non-free) as well as numerous free online tutorials. Ruby even has a nifty online interactive tutorial by _why (you did search didn't you?).
Learning the basic operation and syntax of each language is essential to avoid wasting time with random guessing as to why X doesn't work like Y. (Hint: If X doesn't work like Y, it's because X isn't Y.)
Trying to learn two languages at once is probably not the best idea. Ruby is quite similar to PHP, so the transition may be fairly simple, depending on your prior experience with other dynamic languages. You may find this site useful: http://railsforphp.com/
I recommend you try and build basic applications. Have a target, use the documentation and search the blogs or ask somebody if you're stuck. That's how I learned Ruby.
Also, for Ruby and Rails documentation I like APIdock, too bad they don't have Ruby 1.9 (which I recommend you use).
Click this: code-golf
Then solve all the challenges that got at least 10 upvotes in both Java and Ruby. Don't worry about the golf-scoring part, just do the best you can. If you post your efforts you may get some feedback, and you can compare your results with others.
Keep it enjoyable and simple at first. Use the learning style that works for YOU. If you like reading docs - great, otherwise you'll just end up with a nasty aftertaste. I'll say keep it enjoyable again because your initial exposure/experience can be greatly influenced by how you hit it off with a new language. Try to approach it from an angle of familiarity, you will find that there's some overlap between what you know and the new material. It will help if you can introduce the new stuff with as much ease as possible.
Recall what speaks to you or demonstrates most effectively when you learn and plot your course based on that. If you like books, find one that suites your style. Most of the books will give you most of the same information so what will make the most difference in a case like this is style of the book. For me "Java Objects" by J. Baker did the trick, my friend swears by "Thinking in Java". ... or find some screencasts if you like screencasts.
Then of course fire up the debugger and step though some code, but what ever you do first make sure you're enjoying it.
Start with Ruby. There is a wonderful online tutorial that lets you try Ruby right in your browsers. It covers the essentials of flow control and collections.
http://tryruby.sophrinix.com/
Java and PHP have more in common syntactically than Ruby and PHP. Sometimes that makes it harder instead of easier when learning a new language. That's why I think learning Ruby before Java will help. Ruby is also a lot easier to learn than Java, so the emotional return is greater and you'll be more equipped for Java.
As to learning Java, start with a Tutorial using Tapestry. Not so that you learn Tapestry, but so you gain the benefit of rapid development.
"Java developers love it because they can make Java code changes and see them immediately ... no redeploy, no restart!"
The down side to Tapestry is potential mess of setting up Tomcat.
I'd recommend getting yourself familiar an IDE (i.e. Eclipse) and working through some basic HelloWorld-esque problems. This will let you understand the lifecycle of a java program and some basic I/O. Maybe even take parts of a PHP project you've written and port it over to Java to get the basic syntax ideas down.
I am learning Java.
I have learned and used Ruby. The Ruby books always tell the advantages of Ruby over Java. But there must be some advantages, that's why lots of people (especially companies) use Java and not Ruby.
Please tell the absolute(not philosophical!) advantages of Java over Ruby.
Many more developers experienced with
Java than with Ruby.
Many existing libraries in Java (That
helps JRuby too).
Static typechecking (can be seen as
advantage and as disadvantage).
Existing codebase that has to be
maintained.
Good tool-support.
More and deeper documentations and
tutorials.
More experiences with good practices
and pitfalls.
More commercial support. That's
interesting for companies.
Many of these advantages are the result, that the Java-ecosystem is more matured, than that around Ruby. Many of these points are subjective, like static vs. dynamic typing.
I don't know Ruby very well, but I can guess the following points:
Java has more documentation (books, blogs, tutorial, etc.); overall documentation quality is very good
Java has more tools (IDEs, build tools, compilers, etc.)
Java has better refactoring capabilities (due to the static type system, I guess)
Java has more widespread adoption than Ruby
Java has a well-specified memory model
As far as I know, Java has better support for threading and unicode (JRuby may help here)
Java's overall performance is quite good as of late (due to hotspot, G1 new garbage collector, etc.)
Nowadays, Java has very attractive and cheap server hosting: appengine
Please tell the absolute … advantages of Java over Ruby
Programmers should rarely deal in absolutes.
I'll dare it, and say that as a rule, static typing (Java) is an advantage over dynamic typing (Ruby) because it helps recognize errors much quicker, and without the need to potentially difficult unit tests1).
Harnessed intelligently, a strong type system with static type checking can be a real time-saver.
1) I do not oppose unit testing! But good unit testing is hard and the compiler can be a great help at reducing the sheer number of necessary test cases.
Reason #1. There's a lot of legacy Java code out there. Ruby is new, there's not so many programmers who know it and even fewer who are good at it. Similarly, there is a lot more library code available for Java than Ruby.
So there may be Technical reasons Ruby is better than Java, but if you're asking for Business reasons, Java still beats it.
The Java Virtual Machine, which has had over a decade of improvements including:
just in time compilation in the HotSpot compiler (JIT - compiling byte code to native code)
a plethora of garbage collection algorithms and tuning parameters
runtime console support for profiling, management etc. of your application (JConsole, JVisualVM etc)
I like this Comparison(Found on link Given by Markus!Thanks!)... Thanks to all... i am also expecting some more discrete advantages
And its Great!!
The language.
My opinion is that the particular properties of the Java language itself lead us to the powerful capabilities of the IDEs and tools. These capabilities are especially valuable when you have to deal with very large code-base.
If I try to enumerate these properties it would be:
of course strong static typing
the grammar of language is a LALR(1) grammar - so it is easy to build a parser
fully qualified names (packages)
What we've got in the IDE so far, for example Eclipse:
great capabilities of exploring very large code bases. You can unambiguously find all references, call hierarhy, usages of classes or public and protected members - it is very valuable when you studying the code of the project or going to change something.
very helpful code editor. I noticed that when I writing code in the Eclipse's java editor I'm actually typing by hand only names of calsses or methods and then I press Ctrl+1 and editor generates a lot of things for me. And especially good that eclipse encourage you to write the usage of piece of code first and even before the code is aclually writen. So you do the method call before you create the method and then editor generates the method stub for you. Or you add extra arguments to the method or constructor in the place when you're invoking it - and editor change the signature for you. And enev more complicated things - you pass some object to the method that accept some interface - and if the object's class do not implement this interface - editor can do it for you... and so on. There's a lot of intresting things.
There is a LOT of tools for Java. As an example of a one great tool I want to mention Maven. Actually, my opinion is that the code reuse is really possible only when we have such a tool like Maven. The infrastructure built around it and integration with IDE make feasible very intresting thinsg. Example: I have m2eclipse plugin installed. I have new empty project in the Eclipse. I know that there is a class that I need to use (reuse actually) somewhere in the repositories, let say StringUtils for example. I write in my code 'StringUtils', Eclipse's editor tell me that there is no such class in the project and underlines it with red. I press Ctrl+1 and see that there is an ability to search this class in the public repository (actually in the index, not the repository itself). Some libs were found, I choose one of them at particular version and the tool downloads the jar, configures my project's calsspath and I alredy got all that I need.
So it's all about programmer's productivity.
The JVM.
My opinion is that the JVM (Sun's HotSpot particularly) is a one of the most intresting pieces of software nowadays. Of course the key point here is a performance. But current implementation of HotSpot JVM explores very cutting edge ways to achieve such really great performance. It explores all possible advantages of just-in-time compiling over static, collects statistics of the usage of code before JIT-compile it, optimise when it possible virtual calls, can inline a lot more things that static compiler can, and so on. And the great thing here that all this stuff is in the JVM, but not in the language itself (as contrary with C# as example). Actually, if you're just learning the Java language, I strongly encourage you to learn the details of modern implementations of JVM, so you know what is really hurt performance and what isn't, and do not put unnecessary optimizations in the Java code, and do not afraid to use all possibilities of the language.
So...
it's all about IDEs and tools actually, but by some reason we have them for Java not for any other language or platform (.NET of course is a great competitor in the Windows world).
This has probably been beaten to death, but my personal opinion is that Ruby excels at quickly created web apps (and frameworks) that are easy to learn, beautiful to read, and are more than fast enough for web apps.
Where Java is better suited for raw muscle and speed.
For example, I wrote a Ruby program to convert a 192 MB text file to a MongoDB collection. Ruby took hours to run. And the Ruby code was as simple/optimized as you could get (1.9.2).
I re-wrote it in Java and it runs in 4 minutes. Yes. Hours to 4 minutes. So take that for what it's worth.
Network effect. Java has the advantage of more people using Java. Who themselves use Java because more people use Java.
If you have to build a big software, you'll need to collaborate. By having a lot of programmers out there, you are sure that there will be someone that can be asked to maintain your software even if the original developers have left the company.
Static type checking and good Java IDE offer no magic and this is good for a lot of maintainer instead of Ruby.
It is not sufficient to indicate that java is statically typed and ruby is dynamically typed.
Correct me if I'm wrong, but does this cover the fact that in ruby you can add to and even
change the program (class definitions, method definitions etc) at runtime? AFAIK you can have dynamically typed languages that are not "dynamic" (can be changed at runtime).
Because in Ruby you can change the program at runtime you don't know until you've actually run the program how it is going to behave, and even then you don't know if it will behave the same next time because your code may have been changed by some other code that called the code you're writing and testing.
This predictability is, depending on the context, the advantage of Java - one of the contexts where this is an advantage is when you have a lot of developers of varying skill levels working on a fairly large enterprise application.
IMHO, what one person considers an advantage might be a disadvantage for someone else. Some people prefer static typing while others like dynamic. It is quite subjective and depends largely upon the job and the person doing it.
I would say just learn Java and decide for yourself what its strong points are. Knowing both languages yourself beats any comparisons/advice some other person can give. And its usually a good thing to know another language, so you're not wasting your time.
Negatives for Java:
There is a lot of duplication in libraries and frameworks available for Java.
Java developers/communities tend to create over complicated solutions to simple problems.
There is a lot more legacy in Java to maintain.
Too much pandering to business users has introduced cruft that makes middle managers feel better. In other words, some philosophies in Java are more concerned with BS instead of getting the job done. This is why companies like to use Java.
You'll generally need to write more code in Java than Ruby.
It takes a lot more configuring/installing/setup to get a fully working Java development environment over Ruby.
Positives for Java:
Speed.
Documentation.
Lower level language than Ruby, which could be a good thing or a bad thing, depending on your needs.
None of my points are very scientific, but I think the differences in philosophy and personalities behind Java and Ruby is what makes them very different to each other.
Better performances
There are more choices:
Developers - lots to hire
Libraries - lots of wheels already invented.
IDE's - lots of development environments to choose from. Not only just vi/emacs + a shell.
Runtimes - if you for some reason do not like the JVM you use on the system, you can either download or buy another implementation and it will most likely Just Work. How many Ruby implementations are there?
Please note that this has nothing to do with the LANGUAGES as such :)
Reading up on this : Is Ruby as cross-platform as Java? made me realize at least one factual advantage of java over ruby:
The J2ME-compatible subest of java is more portable than ruby
as long as JRuby won't run on J2ME which may be forever
I'm trying to learn Java but it just seem like there are too many parts to put together.
You have JSP, Java EE, Java SE, Java ME etc....
I can get Netbeans to do basic but just taking a peek at spring framework it seem like a lot of work to get it to run in the ide from the numerous configuration .
I want to get into web programming and maybe mobile.
Any advice?
Another programming language?
Is java this complex or does it get easier?
Java as a language is certainly not too complicated. J2EE in its entirety is only just about feasible for a one-man team - but you rarely need the whole of J2EE.
It's perfectly reasonable for a one-man team to implement a medium-sized web application. I'm not saying one person could write GMail on their own, but you shouldn't be too scared of the technology stack - find the bits you actually need and concentrate on those. On the other hand, that in itself takes a fair amount of experience - I wouldn't really want to be starting off on an enterprise app (even a small one) on my own as a newcomer to Java.
Start small. Learn the core (the language, IO, collections) - and then start with small projects. Work out whether you want to be in mobile, desktop, server or whatever - don't try all of them simultaneously. Gradually you'll build up your experience.
It's not that Java-the-language is complex, it's that vast libraries and frameworks exist that can help you do your work. This is true for many programming languages. Look at CPAN for Perl, for example. What language to use depends in great part on what your goals are.
You can start simple and work your way up to larger and larger projects.
Java is by no means too complex for a one-man operation, but learning any form of full-formed web programming is a lot to learn when it's all new. If you were looking at .NET for the same purpose, there is a lot there too.
Unless you are doing huge-enterprise applications, ignore all of J2EE except for JSP and JMS and a very few other components. The lion's share of J2EE is only useful in the context of an enterprise application that needs to scale, and in fact can be harmful when used in smaller applications.
The frameworks such as Spring, Hibernate, Apache-*, Web Services, and so on help you do your job, but are yet more things to learn to do your job. There is a lot to learn.
Should you use Java? Well, quite a lot of development is done with LAMP (or WAMP): Linux (or Windows) + Apache-HTTPD + MySQL + PHP. With this, you don't need to worry about Java or .NET or any of those frameworks. LAMP/WAMP works very well for a wide class of applications.
Java and .NET on the server are (sort of) more appropriate for larger services, but once you are familiar with them, they work just fine for smaller services as well.
You have to decide what your exact goals are, then look at how people have implemented the kind of thing that you're looking at doing. This will help you figure out what technologies are the most necessary for the niches you're looking at going into.
Java -- the language -- is one of the simplest strongly typed languages in existence. Vastly simpler than C++ or even its close cousin C#, I would argue.
The standard APIs/libraries really are huge, but nobody learns the whole thing. You're suffering from the intimidation all beginners feel when they look at something that big and new, but this will pass as you just do stuff. First, you need to learn the standard utility stuff -- the collections in java.util, mostly -- and then, for basic web dev, probably next the JDBC library and Java Servlets and JSP. And that's it.
As an alternate tact here...
Another problem you will encounter in Java is Choice. You have a LOT of it in terms of frameworks and technologies etc.
My best advice is search around for about a day if you're so inclined to find what technologies attract you, or who's arguments sway you. Then, pick one. ANY one. Really, it doesn't matter, especially for a first project. They all have learning curves, they all have strengths and weaknesses, they all have fans and foes.
The key though, is once you have chosen, STICK WITH IT. You will inevitably stumble upon some problem, you will pose this problem to someone else, someplace else, and they will say "oh, you should have used QED instead of KnifeForkSpoon". And you will second guess yourself, go off and hear about the wonders of QED, and all of the kittens born under it and hungry children fed by it. If you succumb to that siren song of "greener grass", your project will flail. (Not fail, flail.)
Don't be wooed, don't fall for it. Just fix your problem and move on. At the end, and you're on a new project, THEN go and look for the more bestest greatness silver bullet.
As an aside, if I were just getting in to web programming today in Java, I would humbly offer this simple recipe:
JSP 2.0 with JSTL for markup and presentation
Stripes or Struts 2 for logic (note Struts 2 (TWO), Struts 1 is plain evil)
"raw" JDBC with a database pool for persistence
Tomcat or Glassfish for a container (tomcat more popular, GF easier to use out of the box)
Netbeans or Eclipse (NB is easier to use out of the box)
This uses the most fundamental, yet functional facilities for web apps in Java today, lots of applicability, and solves the major issues of a web app without covering them up with thick, impenetrable layers.
You will learn a lot using these "crude" tools.
You need to learn to pick your battles. Covering the whole J2EE is a massive task and, for most, unnecessary to begin with. I think a common mistake for beginner programmers is that they think they need to learn everything. You'll find your time much more productive if you focus on the core language constructs to begin with, and focus on either web or mobile programming.
You'll be extremely surprised (and pleased) at how much you can carry over from one area to the next. Once you know the language, the different libraries for different platforms are just tools...Stick with Java. It is a good language to learn.
Can I take "get into web programming" to mean that you're just learning web programming in general? If that's true, if you have the time you might consider setting Java aside temporarily and giving LAMP/WAMP a closer look as Eddie suggested. (Though I'd personally use Perl instead of PHP. PHP is sexier resume fodder and lets you do some very cool things on the front end, but in my experience, when it comes to writing server-side code Perl simply blows PHP's doors off. And I've heard that the HTML::Mason extension puts Perl on pretty even footing with PHP's front-end niftiness, but I haven't used it myself.)
I've made a living writing writing web apps in Java and web apps in Perl. I'm fond of both languages, but as a learning tool, I'd put Perl well ahead of Java. As you're finding out, Java's a bulky bastich. Part of that is, as others have mentioned, a function of Java being a mature language with a variety of extensions that are unlikely to apply to your immediate needs. But even stripped down, you'll still need to deal with quite a bit of overhead before you can even get your first "Hello World" web app to run. Comparatively, you'll get rolling much quicker with Perl.
(In fact, Java tends to be pretty verbose in general compared with other languages. That's not necessarily a bad thing; my one big complaint with Perl is you often encounter code that leverages various shortcuts and side effects to do an unholy ton of work in just a few lines. This code is often brilliant, elegant, compact, and utterly bloody unintelligible to a non-expert. Terseness is not a virtue for the poor idiot who has to modify code six months after it was written -- especially when you wind up being the poor idiot in question.)
And as a way of learning web programming, Java's sophistication can actually work against it. As a professional, I'm glad Java's web-based tools automagically take care of a lot of grunt work for me, like session management. But I didn't completely understand what it was doing until I was thrown into a Perl-only environment and had to deal with all that stuff myself.
I guess it depends on why you're doing this and how much time you can devote to it. If time is limited and you're looking for something that will appeal to prospective employers, then yeah, Java's an excellent choice, and you've gotten some solid advice in this thread about how to get started using it.
But if you do have the time, I highly recommend giving old-school Perl/CGI programming a sniff. It ain't a particularly marketable skillset anymore, but you'll learn things worth knowing.
You don't have to learn all of Java and its libraries. Just learn what you need for the job at hand. You will find there are plenty of options, but you don't have to get the best option every time.
If your base programming concepts are clear no
language should be difficult for you. I have switched over from vb 6 to java to c# to objective c now. What really makes a coders life easy is the IDE, debugging tools, documentation and lot of blog posts which google can search :-) regarding one man team my personal view is I am at my best when left to code and research alone with the help of google and stack overflow ofcourse :-) so I do think in programming large sized teams often lead to more screw ups than results
Java is not a complex language, altough it looks frightening at first.
I started learning Java from home, not a school, at 15 years of age (yes, yes, I know that's nothing to brag about) trough a book. It's a norwegian book, so I won't link to amazon;)
After reading/hacking trough half the book I found out I was better off ditching the book and looking for more stuff online. Google really IS awesome!
I would often read about all the fancy features of the JVM, frameworks, third-party libraries, JSRs and so on, and how much better my life would be with them all, but I just ignored them all. Yes I tried, but found it too confusing to learn Java and a framework that wasn't really necessary, at the same time.
Some people gave me hell for not using insertRandomLibraryName() or insertFancyFrameworkName(), and told me all about how much time and effort i would save, but I'm glad I didn't listen.
Now times have changed, and I still learn new things, or easier ways to do old things, every day. And I'm glad I took the time to learn the language itself before all the fancy stuff.
Also, don't use a notepad for writing code, use an IDE from the beginning. The only one I've ever really used is NetBeans, so that's the only thing I can recommend, but I sure am really happy with it!
As to Java SE, ME and EE, start with SE, and you'll propably find that it's enough for now. You don't have to use EE to write for the web, SE is fully capable of webernet stuff;D