Why Java? Tales from a Python Convert

http://sookocheff.com/post/java/why-java/

by soofaloofa • 11 years ago

75 100 11 years ago

golergka• 11 years ago

These examples look like C# 2.5 with a little bit of LINQ.

tracker1• 11 years ago

IMHO, C#'s tooling and is definitely ahead. Java is starting to get there, and I can see why the JVM is still popular. But given the actions of Oracle and MS as of late, I think I'd take MS. VS starter projects are easy to setup and run... Every Java application I've worked on has been an exercise in frustration just getting the environment setup.

soofaloofa• 11 years ago

I'm also a fan of C# but deploying .NET has been a sticking point. I'm hopeful that Microsoft's open source efforts fix this.

LoneWolf3• 11 years ago

Could you elaborate? Java has maven archetypes that allow that, create a base project with no effort and the right dependencies in place. From there on compiling is just a command away, and running it usually too.

chris_overseas2• 11 years ago

I've found the opposite. For me, C# as a language is nicer than Java. The libraries themselves are a bit of hit and miss - personally I've found Java's concurrency APIs to be much better than C#'s, however I've found the async and LINQ support in C# to be far nicer than the Java equivalent (including Java 8 streams etc). But tooling... wow... Visual Studio feels like such a huge dinosaur compared to IntelliJ IDEA. Not to say it's that bad, but IDEA is so far ahead of any other dev environment I've ever worked with it's not even funny. Even adding Resharper to VS doesn't feel much more than scratching the surface. As always, YMMV.

SEJeff• 11 years ago

Agreed. On the other end of the spectrum, you have cookiecutter:

https://github.com/audreyr/cookiecutter

benedictp• 11 years ago

Take a look at Kotlin https://kotlinlang.org/ I know there is also Scala and other JVM languages. But I'm also an Android developer and Kotlin works really fine with Android-Studio (both from JetBrains).

zem• 11 years ago

kotlin definitely looks like a drop-in replacement for java. fairly conservative set of extensions, seamless interop, and fixes a bunch of annoyances.

ubercow2• 11 years ago

The one thing keeping me away from Java still is the awful experience around modeling data.

Compared to something like a case class in Scala or even autoproperties in C#, writing classes with a bunch of getter and setter methods just to keep state is really tedious.

LoneWolf3• 11 years ago

I'm seriously tired of this argument against getters and setters, just generate them with the IDE some also support collapsible regions with a start and end comment, and forget about them.

So considering you can just generate and forget why is it tedious?

cballard3• 11 years ago

If it can be generated, why doesn't the compiler do it for you? This shouldn't be done at the IDE level.

rakoo2• 11 years ago

Because it's actually useless, having the work been done by someone else or something else means the work is still done, and you still depend on that 3rd-party.

mgkimsal• 11 years ago

I really prefer Groovy's approach - default get/set behaviour is provided at compile time, but you can override in code with explicit getter/setter methods. Really seems to be the best of both worlds.

encinarus• 11 years ago

One thing to look at for Java would be auto/value (Immutable value-type code generation for Java 1.6+ by Google)

https://github.com/google/auto/tree/master/value

Not the same as what you reference in the other languages, but useful if you find yourself dealing with it in java.

ubercow2• 11 years ago

This is really cool! I had no idea something like this existed.

opmac• 11 years ago

Use `public final` fields and put them in the constructor. Use builder classes to handle optional parameters.

Hermel• 11 years ago

That's because Java is object-oriented. Data and the functions that operate on that data are not supposed to be separated. A clean object-oriented design has no plain getters and setters.

Retric• 11 years ago

A point (x,y) or (x,y,z) class seems to be the obvious exception.

Anonymous objects can also be really useful.

pzone• 11 years ago

That's because Java is pedantically and obsessively object-oriented

elchief2• 11 years ago

lombok

latchkey• 11 years ago

https://projectlombok.org/

Integrates with the IDE to automatically provide getter/setters and additional features.

ajnin• 11 years ago

... which is a hack using undocumented/non-public APIs of the Java compiler, so that's not really a viable solution.

zo12• 11 years ago

Or just use public instance variables, really. Unless you plan on explicitly specifying how your internal variables are going to be used and accessed, you don't get a free-lunch.

agumonkey• 11 years ago

Meijer or Oderski advised to use Kotlin / Ceylon to lift the burden of Java POJO. They have enough syntactic sugar and type niceties to make you happy again.

Probably Meijer ...

astral303• 11 years ago

Don't use setters and getters in your models.

Use public fields, add getters and setters if you have to. Serialize your POJOs using Jackson. All modern data frameworks can deal with public fields just as well as getter/setter combinations.

(Unless you are publishing a public API. In that case, you can't easily convert a public field to a private field/getter/setter setup if needed, as the cat is out of the bag and clients have code against the public field.)

Do I wish there were auto properties like C#? Oh yeah, I'd love that. But I do find modeling fairly easy.

I also lament having to manually maintain equals/compare/hashCode/toString implementations. However, with IDE auto-generation of code (using IntelliJ) makes this merely noisy and annoying, and not a time sink or a constant source of dumb errors.

cgs1019• 11 years ago

Google's auto library, auto/value in particular, is worth a look: https://github.com/google/auto/tree/master/value

wtetzner8• 11 years ago

Yes, in the Java projects I work on we use Lombok [1], which is nice, but is also a hack around the fact that Java makes these things hard.

https://projectlombok.org/features/index.html

draw_down• 11 years ago

Every time you see "it just works", run.

thefastlane2• 11 years ago

i don't care what lipstick you put on that pig: when something as simple as writing to stdout requires that i first create a new class, i'm not interested.

Edit: i do consider this a legitimate issue with how Java 'does' OO. i'd be curious to understand downvoters' thoughts.

One more edit: wow, tough crowd. for those not familiar, i'd suggest reading Steve Yegge's essay "Execution in the Kingdom of Nouns"

Retra• 11 years ago

It's basically just a namespace for the function.

cooper12• 11 years ago

    System.out.println("Foobar");

Either you're referring to something else or you misunderstood the language. The `out` stream is static so there is no need to create your own class first. (http://docs.oracle.com/javase/7/docs/api/java/lang/System.ht...)

umanwizard2• 11 years ago

You're probably getting downvoted because it's factually not true.

System.out.println("Hello, world!");

No new classes there.

thefastlane2• 11 years ago

how would you compile that? here's what i get:

  test.java:1: error: class, interface, or enum expected
  System.out.println("foobar");
  ^
  1 error

erokar• 11 years ago

Stockholm syndrome.

bsder• 11 years ago

java.util.concurrent is so much better than anything else mainstream that it's ridiculous.

je42• 11 years ago

I don't see any valid arguments that make Java 8 strictly better than any of the alternatives. These languages are all in the same rough ballpark. Your particular use case/environment will determine mostly which Language you should be pick.

js82• 11 years ago

"the JVM has excellent support for production logging and production monitoring, allowing you to easily monitor performance metrics down to an individual thread"

Is it "excellent" compared to z/OS and mainframe (SMF and RMF, specifically)? I sincerely doubt it, but I would like to know if there is someone who can compare. I don't think any platform can match z/OS in the visibility into the system, but I am not enough expert in Java to really compare.

chris_overseas2• 11 years ago

You're comparing an OS independent language to an entire operating system? I think you're probably right, I don't think there is a sane comparison. But I don't think that's what the parent was referring to.

I'm not sure there are too many languages that provide (eg via slf4j or JMX) extremely customisable, universal logging and monitoring across multiple libraries that are used together in a single application. That's not a function of the language itself though, just the maturity of the libraries and ecosystem around it. Combine that with the tooling (eg IntelliJ IDEA) and no matter how much you might think Java as a language is verbose/clunky/crappy (which I tend to agree with), it's pretty hard to beat for large, complex, maintainable systems.

js82• 11 years ago

"You're comparing an OS independent language to an entire operating system?"

No, I am not comparing Java, but JVM. JVM is a platform, so it should have insight what's happening on it, don't you think? Whether this insight comes from the platform (JVM or z/OS) or the underlying system (native host OS or mainframe) is irrelevant - you probably want both (and in z/OS you get both).

Whether Java (the language) is clunky is irrelevant - z/OS has lot clunkier languages on it (application development is huge pain on z/OS compared to JVM), and I still think z/OS beats JVM for large/complex/maintainable systems. ;-) (Basically for the same reason - more mature.) z/OS has many logging and tracing functions, at different granularity, some of them are assisted with mainframe hardware. I don't see how JVM could beat it, but I may be wrong.

pka2• 11 years ago

Java’s type system, while verbose at times, allows you to write code that largely “just works”.

NullPointerException would like to have a word with you about that.

In all seriousness, it feels unreal that people can be that impressed by Java's safety or lambdas. Makes you shudder to think about what they've used before that.

IshKebab• 11 years ago

Python. Says it in the title.

throwavay_java• 11 years ago

AttributeError: 'NoneType' object has no attribute

isn't much better.

Java might not be perfect, but it does let you catch a lot of problems at compile time rather than run time, which is a step in the right direction. The alternative (run it and see) gets old fast.

pka2• 11 years ago

While I agree - this particular alternative is worse - it's not the only alternative. I was talking about more expressive type systems, not less.

dragonwriter• 11 years ago

Java provides less of the benefits of static typing than many other statically-typed languages (even than others available on the JVM), at a much higher cost in required ritual invocations made to the type system.

Yes, there is a value in static typing, but that value is minimized when you have a type system that isn't particularly expressive and/or have to make add a lot of redundant code to satisfy a comparatively unsophisticated type checker.

Java may have gotten slightly better since its poor performance in cost:benefit terms when it came to static typing helped launch the surge in popularity of dynamic languages, but its still not a great poster child for the benefits of static typing.

angryasian• 11 years ago

Now with Optional in Java 8 its not an issue.

alexkindel• 11 years ago

Optional is great, but it would be far more powerful if types not wrapped in Optional were guaranteed to not be null.

wtetzner8• 11 years ago

It's still an issue, because as far as the type system is concerned, every reference type can still be null.

Optional gives you a way to avoid using nulls, but null is still in the language and libraries still use it.

sytelus2• 11 years ago

OP is glossing way too many things.

1. Desktop users are tricked in to installing Ask toolbar crapware. Which other language tricks users in to doing that?

2. Java development actually have languished for very long time and it is very recent that it started to catch up with C# and other modern languages. Java forums are filled with cries and screams for adding these improvements for years on.

3. Java is built on language concepts that are now 20 years old. Back than people wanted every language look like C++. The millennials think outside the braces. They expect language to infer types instead of repeatedly being specified all over. They expect REPL. They don't want everything modeled as object and so on. Mature language does not equal modern language.

3. Java is not truely "open source" or "free". Ask Google and Apache Harmony for the legal battles they had to fight with Oracle.

4. If Microsoft had done what it's doing with C# and .Net back in 2000, I highly doubt Java would be as popular as it is now. In other words, things can be popular even while being technically legging behind. This is not to say C# was initially just a Java copy cat but it did grew up fast while Java folks set on their laurels.

5. Java is owned by Oracle. Enough said.

I think modern languages should not have obligation to look like C/C++ and it should use advances in automatic type inference, functional paradigms etc. Anything 20 years old would have great libraries and VMs, but then mainframes and Cobol were also very safe, "reliable" and had great libraries and infrastructure at some point. It's ok to use mature tools to get shit done now but proposing them as new frontier doesn't make sense.

chrisseaton2• 11 years ago

Java is built on language concepts that are now 20 years old.

Name me at least one language, even remotely mainstream, that is built on language concepts which aren't at least 20 years old.

sytelus2• 11 years ago

Well, you know Archimedes and Aristotle had thought through all concepts in everything so nothing is new really :). Or more recently, all languages are just little flavors on Turin machine or Lambda calculus. But practically, Python had been one of the language that sets aside itself dramatically. It's still surprising to me that language designers - including folks on Go team - still have hard time thinking outside of braces. It's almost disguesting how C# requires braces and uses == vs =. When you look at Python, it's apparent that Guido van Rossum had no inclination to do things as it was popular at the time and he put a lot of thought in removing redundancy, putting else clause in for and so many other cool things that are now so obvious.

edwinnathaniel2• 11 years ago

Seems like these points glossed a lot of things as well.

I mean... what language that locks you down with one specific operating system (up until recently when they lost the market)?

I see other languages copying Java tools/ecosystems but I give you 10% point for which Java syntax was behind for years.

Your point #4 don't make any sense at all. The only reason Microsoft goes OSS these days because they simply _lost_ their bread and butter: developers. Back then, they haven't entirely lost them so there's no way on earth that Microsoft will be pulling whatever they're doing these days.

It's ok to use mature tools to get shit done now but proposing them as new frontier doesn't make sense.

Unfortunately none of the current language seems to get shit done in a reliable, reusable, and ubiquity as Java.

openplatypus2• 11 years ago

The millennials think outside the braces.

Please don't generalize. You have not been elected to represent all millennials.

dozzie2• 11 years ago

1. Desktop users are tricked in to installing Ask toolbar crapware. Which other language tricks users in to doing that?

.NET requires you to install Windows. I think it's the same category.

wtetzner8• 11 years ago

Maybe even worse.

LoneWolf3• 11 years ago

About 1, having installed the JDK dozens of times I have never seen the ask toolbar crapware, could be true with the browser plugin (that should have died a long time ago) or the JRE (that I never needed to install).

About 3 to be honest I don't care at all of having braces, I actually dislike python because its lack of braces and what says if something is in a block is the indentation (I don't want to care about it when writing code, there are IDEs for that, specially when I move code around a lot), unless I am doing some quick tests on something and I dont have a minimal environment I do need a REPL at all (Java 9 may take care of that).

True that Java is not exactly truly open source, I have to agree with that.

Java being owned by oracle may be bad but being owned by a bad company does not make it a bad language.

boultonmark2• 11 years ago

I can't imagine you were ever really a Python programmer if you enjoy progamming in Java. It's almost the anti-python

svisser• 11 years ago

No true Python programmer would switch to Java?

boultonmark2• 11 years ago

ssijak• 11 years ago

I use both Python and Java (among other languages) for large production systems and enjoy both..

thinkersilver• 11 years ago

I love the jvm, I love the tooling and the ecosystem, but Java I do not love. The author presents many of Java 7/8 features as a reason for Java's greatness. The language features of Java 7/8 are really not that compelling. Let's consider that C# has had much a more progressive approach to language design for a while now.

Most places I've worked at recently have moved to Java 8 because 7 has been EOLed. It feels like we were pushed onto 8 rather than enticed by its shininess.

What makes Java great isn't java it's the jvm. It's such a brilliant piece of engineering. What makes the jvm 'meh' is it's association with java. The arguments the author makes about Java being great are in my eyes really about the JVM, its tooling and its languages.

mattdlondon• 11 years ago

Just a spin on this: as a java developer that recently started doing a lot of python, what has really annoyed me (apart from the utterly woeful IDE functionality compared to typed languages) is the extra "boiler plate" thinking you need to do with python because of the dynamicness meaning you have to keep the types and classes you're using for your codebase in your head, rather than letting the computer deal with that.

e.g. you have a function with a "database" parameter ... it could be a string, it could be a dict, another class, or even a number. There is no way to know apart from back-tracking through the code (or run it and wait for it to fail with a TypeError when that code gets hit). With java you just read the type off the screen and you can get on with solving the problem at hand without extra thinking, and even if you do screw up your IDE tells you right away with a nice squiggly red underline, or if you're not using an IDE during compile time. With Python you might not find out about that TypeError until that 3am pager call.

People have suggested that the answer to this is forcing strict naming conventions and/or strict docstring conventions ... but if you are going to go with that level of extra work of typing "database_string" or """Lots of long docstrings explaining exactly what type the database parameter is.""" (and maintaining it!!!),you're not saving any boilerplate (biggest complaint I've seen levelled at java) so why not just use a statically typed language ?

tl;dr - for me, python adds cognitive load of keeping the minutiae of the code in my head on top of solving the actual task at hand.

That said, I like the "pick up and go" prototyping feel of Python for quick jobs - java sucks for that.

mwcampbell• 11 years ago

You didn't say anything about unit tests. Those tend to be the technique that proponents of dynamic languages promote for catching errors earlier.

gozur882• 11 years ago

It's pretty difficult to defend the proposition that catching errors in unit tests is superior to not making them.

rpeden• 11 years ago

Although it won't help when using other people's libraries/code, when you're building your own code then you'll probably enjoy Python 3.5's type hints on function parameters. They negate the need for doing hacky things like specifying types in docstrings.

https://docs.python.org/3/library/typing.html#module-typing

IndianAstronaut• 11 years ago

This also makes working with Python, even in an IDE, much trickier than Java in an IDE.

cantastoria• 11 years ago

Bingo! Coming from C# and C++, I had exactly the same realization using Python (before I switched back). I always ask Python programmers "but are you just keeping track of the types in your head?" because it's impossible to keep myself from doing that. If Python (and dynamic languages in general) are just pushing the type checking into the programmer's lap, I'm not sure what the advantage is other than less verbose (looking) code.

gozur882• 11 years ago

That's the problem I had with perl. Sometimes one plus one is two, sometimes it's eleven, and the interpreter doesn't always do what you expect.

openplatypus2• 11 years ago

To be completely fair PyCharm is darn good with Python. PyLint will get you to quite comfortable place as well.

Thanks to this thread I just discovered the state of type hinting in Python 3.5.1 and I am super excited.

I can imagine working on huge code base and having a beef with Python but being a Java developer I think that would be using the tool incorrectly. The reason why I am saying this is that in Java world we (or some of us) work on large projects, we have multi-module projects with millions lines of code.

Whenever I think about Python project, I like to think that I would build series of small, independent modules. Maintain them separately. Thus limiting burden of dynamic language. In Java/JVM land you can achieve the same with small JARs. But we often don't (for various reasons).

TL;DR: There are more than decent tools for Python. Java =/= Python. Development approach matters.

thothamon• 11 years ago

To me, the article doesn't really sell Java the language. The big benefits are in the JVM and libraries, which support many languages far superior to Java. The only virtue of Java the language might be the programmers who know it, and even there, many programmers are not familiar with the new features of Java 8.

csense• 11 years ago

Maven's one of the most disgustingly over-engineered, obtuse, verbose, tightly coupled pieces of s...oftware I've ever seen. From the project's own 5-minute introduction [1]:

If you have just installed Maven, it may take a while on the first run. This is because Maven is downloading the most recent artifacts (plugin jars and other files) into your local repository. You may also need to execute the command a couple of times before it succeeds...The POM is huge and can be daunting in its complexity...You executed the Maven goal archetype:generate, and passed in various parameters to that goal. The prefix "archetype" is the plugin that contains the goal... the second [command] is simply a single word - package. Rather than a goal, this is a phase. A phase is a step in the build lifecycle, which is an ordered sequence of phases. When a phase is given, Maven will execute every phase in the sequence up to and including the one defined. For example, if we execute the compile phase, the phases that actually get executed are [list of 6 items]...Although hardly a comprehensive list, these are the most common default lifecycle phases executed [list of 10 items]...

So in order to use this, I have to understand its own specialized non-standard vocabulary, like artifact, repository, archetype, plugin, goal, package, phase, lifecycle...the build configuration is in XML...it does a lot of stuff automagically, like executing five extra phases or downloading dozens or hundreds of executable files from the Internet.

People love Maven for some reason, but I'll use shell scripts or Ant for my Java builds, because when the build breaks [2], I want to be able to understand what's going on without having to read a few hundred pages of the build system manual.

[1] https://maven.apache.org/guides/getting-started/maven-in-fiv...

[2] Anyone who's ever worked with any build system knows the build will break.

nikdaheratik• 11 years ago

I think the author has set an impossible task for the article: trying to sell Java without giving any specific use cases. Generalities don't cut it, especially if you've already invested time learning how to do something in Python, which isn't perfect, but can match the JVM in the areas that it does excel at (e.g. problems that need NumPy or Django).

Java is irritatingly pedantic about sticking to its idea of how OOP should work. It has that design by committee feel to it that enforces some idioms that please no one (like pushing object Factories). If you need to get a prototype out or want something that can let you automate a task quickly with little BS, you don't want Java.

Java is good for enterprise developers as it tends to reign alot of the cowboy tendencies of some programmers and helps to force everyone on the project to use the same clearly defined, well planned (and less elegant) APIs and other systems. And the JVM keeps you from being tied into some specific hardware that may go away in the future.

It's the difference between a toolkit to design and build a cool building, like the Space needle, or you need to coordinate a huge number of contractors because you're building the Big Dig or Chunnel.

Why Java? Tales from a Python Convert

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