Ask HN: What's Java used for?

#1

Post by oldmanstan » Tue, Sep 28, 2010, 5:43 AM UTC

I just start learning it in school. We're making a game.

What can it be used for on the web, though? What big companies use it primarily?

Re: Ask HN: What's Java used for?

#2

Post by dbingham » Tue, Sep 28, 2010, 6:41 AM UTC

It can be used for just about anything except maybe low-level operating system stuff.

"What should it be used for?" is a different question and depends at least somewhat on your preferences.

I go to Java when I want a desktop application that should be portable, doesn't need to be lightning fast, doesn't depend on any low level operating system stuff and that I don't mind losing pointers and memory management for. In other words, most of the time I'm writing a non-web application, I go to Java.

I personally don't like using it for web stuff except where small applets are concerned. I've had issues with it (it including Java, JSP, etc) and generally find it to be too heavy and not practical for web development. But that's just my opinion.

Re: Ask HN: What's Java used for?

#3

Post by thaumaturgy » Tue, Sep 28, 2010, 6:44 AM UTC

A buddy of mine is a programmer at AT&T, and they (mostly he) have developed a pretty incredible push notification and messaging system using Java on the back-end. He claims that they're getting some pretty astounding message processing rates. I keep having trouble thinking of Java as "fast", but that might just be due to really crappy desktop app experiences.

But anyway: one of the biggest companies in the U.S. uses Java to do some really cool stuff.

Re: Ask HN: What's Java used for?

#4

Post by gojomo » Tue, Sep 28, 2010, 7:06 AM UTC

In the social web area, LinkedIn uses a lot of Java. Hi5, too -- at least before the recent games focus, and maybe since.

Lucene and SOLR for search are behind lots of websites -- public and intranet.

Hadoop and related tools -- MapReduce, HDFS, HBase, etc. -- are big in large-data, big-calculation systems, even when front ends are implemented in other dynamic languages.

Looking over all the open source Java projects at the Apache foundation may give a sense of range of uses on the net. And with the growth in alternate JVM languages -- like Groovy, Clojure, and Scala -- a bit of Java, or some Java libraries, may be part of projects in those languages as well.

Re: Ask HN: What's Java used for?

#5

Post by weego » Tue, Sep 28, 2010, 7:53 AM UTC

Almost all the big online gambling platforms (sportsbooks and casinos) are written in java.

Re: Ask HN: What's Java used for?

#6

Post by FernandoEscher » Tue, Sep 28, 2010, 7:57 AM UTC

Google got Java libraries for most of their APIs, and for developing over App Engine.

Blackberry and Android got mini Java sdk for developing movile apps.

Or if you want to develop over Cloud Computer systems you might want to give it a try to Hadoop, that is also written in Java.

So, yes, there are tons of real implementations in Java, even though is not a language I could say I love...

Re: Ask HN: What's Java used for?

#7

Post by lukefabish » Tue, Sep 28, 2010, 8:11 AM UTC

In corporate-land, enterprise web applications are generally .net or Java.

Enterprise Java is referred to as Java 2 Enterprise Edition (J2EE). In this case, the web output a user sees in a browser is generated on an application server using a mix of Java code and templated HTML/CSS/Javascript/etc.

Re: Ask HN: What's Java used for?

#8

Post by bensummers » Tue, Sep 28, 2010, 8:12 AM UTC

Remember that the runtime, the JVM, is separate to Java the language. Lots of interesting languages run on the JVM, like JRuby, Clojure, Jython, and they get access to a scalable optimised runtime and lots of useful libraries.

Re: Ask HN: What's Java used for?

#9

Post by dikbrouwer » Tue, Sep 28, 2010, 8:51 AM UTC

lukefabish wrote: post #7

In corporate-land, enterprise web applications are generally .net or Java. Enterprise Java is referred to as Java 2 Enterprise Edition (J2EE). In this case, the web output a user sees in a browser is generated on an application server using a mix of Java code and templated HTML/CSS/Javascript/etc.

Yes, but the interesting question is why? Many large corporations indeed use Java, and the often-touted reason is safety and/or speed. Is that still a valid answer in today's web dev world? What would you recommend that AT&T for example uses if they could start all over again today?

Re: Ask HN: What's Java used for?

#10

Post by david_p » Tue, Sep 28, 2010, 9:36 AM UTC

dikbrouwer wrote: post #9

lukefabish wrote: post #7

In corporate-land, enterprise web applications are generally .net or Java. Enterprise Java is referred to as Java 2 Enterprise Edition (J2EE). In this case, the web output a user sees in a browser is generated on an application server using a mix of Java code and templated HTML/CSS/Javascript/etc.

Yes, but the interesting question is why? Many large corporations indeed use Java, and the often-touted reason is safety and/or speed. Is that still a valid answer in today's web dev world? What would you recommend that AT&T for example uses if they could start all over again today?

IMO, Java is appreciated for the following reasons:

  - there are plenty of reliable open source libraries (see Apache)
  - it is easy to learn and to maintain
  - the IDEs are good (IntelliJ IDEA !)

So, yes, this is still a valid answer, IMO.