4 ms·

If you are a Java expert and know nothing else, roll with it: learning something significantly different from scratch to a degree comparable with your today's J

If you are a Java expert and know nothing else, roll with it: learning something significantly different from scratch to a degree comparable with your today's Java expertise will take a long time. That part he got right. But if your toolbox is bigger to begin with, I see very little advantages in using Java and his arguments aren't persuading: Java is a memory hog (which matters more than CPU cycles in the era of VPS), Java starts slow - it won't allow fluid workflows like Python/Ruby do. Java doesn't interface well with UNIX or anybody else for that matter. Java-centric libraries and frameworks, while numerous, are tedious to work with: they tend to be over-engineered, overly-relying on XML to an unhealthy degree, hard to navigate and verbose to use. I am coming from Microsoft/.NET and Ruby/Rails background and even after a year of adjusting, everything in JVM-centric world feels overly complex, slow and "rigid". Java people seem to swim in their own definition of object oriented programming and oh my... they stick with it. Even interviewing "Java-minded" people is painful. All in all, I am 100% with the anonymous poster he quoted in the beginning of his post: "Its great for consultants because it means more billable hours" Not in a sense that it takes a lot of typing, but simply because there're lots of excuses to bill more for.

Tobias42 17y ago
> Java is a memory hog Tomcat with a simple app installed uses about 60 MB when it's idle and not much more with dozens of parallel requests. With Rails you need about 40 MB per instance for a very simple application. Edit: And Java is lightning fast. An old project of mine running on a tomcat on a crappy VPS with 192 MB RAM serves the home page in about 100 ms, and without any manual caching, although it executes 7 queries to a postgres-db. A simple rails app which I deployed on a VPS with twice as much RAM takes at least ten times as long to deliver the home page. And the only "dynamic" thing that happens on the home page is the formatting of a date. There is no database involved.
- davidw 17y ago
  Honest question (I've never done Java web stuff): what does that 60MB actually buy you? Rails gives you a whole lot of tools in that space.
  - old-gregg 17y ago
    It's hard to compare but Tomcat is functionally equivalent to something like Passenger, Paster or Mongrel. And last time I looked, it actually ate 80MB. It doesn't make sense to compare empty application servers: it is your running application you should be concerned with. JVM is fine if you're running only a single instance of it: just use threads instead of processes. The problem with JVM is that you often can't afford to have several of them running: in Java world everything is measured in hundreds of megabytes, that's the smallest unit of measurement they use (often supplemented with references to 32GB servers, "they're so cheap now"). Check out Batik Java library for rendering SVG. A single 45Kb SVG file, when fully parsed, eats up 150MB right here on my laptop. After serveral repeated test runs, JVM memory usage grew to a sweet 540MB, where it stopped because I capped it there via -Xmx. For comparison: Inkscape, which is an entire SVG IDE powerhouse, not just a parser, consumes only 3MB more when I open the same file in it, so that's like 50x less, plus it doesn't grow. See, unlike CLR or Python/Perl/Ruby, JVM truly is a virtual computer, i.e. running a WAR file under Tomcat is kind of like running an Office 2008 inside of an invisible VMWare image with Windows pre-configured to occupy either 500MB or 1GB or comparable number. I just don't get why Java people are so damn proud of it. Moreover, they find nothing strange about this bizarre arrangement because they're completely absorbed by that JVM instance. To demonstrate why Java doesn't belong on UNIX I invite you to implement find, grep, less and sort as Java programs, pipe them all together in a bash console and enjoy the show. :-) In the end, there is nothing with Java that can't be dealt with by paying a few extra $ for hosting. The main issue is that JVM is an OS, a much more corporate, boring, uptight and over-engineered (and much less fun) than UNIX is. I also want to address some of Tobias42 comments: for the most part I absolutely agree with him, except I don't follow his comparisons to Rails: we are comparing platforms here, not languages or frameworks. JVM is a memory hog compared to UNIX, and if he wants to compare Rails, I'd recommend loading his Rails app into JVM via JRuby/Tomcat and seeing what happens to his 192MB VPS box. Moreover, I wouldn't call 100ms/page (i.e. just 10 requests/second) "lightning fast", which makes his next comment about "Rails taking 10x longer" sound a bit strange: how hard does one need to try to build a web application with 1 request/second performance?
    - Tobias42 17y ago
- umjames 17y ago
  192 GB of RAM or 192 GB of disk space?
  - Tobias42 17y ago
    192 MB RAM. Sorry, I corrected the typo.
umjames 17y ago
So very true. Since learning Ruby, I've noticed that my attitude towards Java has taken a complete 180. It feels like doing anything in Java is like mowing your lawn with a pair of hand scissors. You can get the job done, but it takes a lot of extra steps/effort when compared to more powerful programming languages. I don't think that the majority of people who are using something else besides Java to build their web app are doing so just because they read some Java-bashing statements on a website. They're either basing their technology choices on prior experience or are just picking something that appeals to them and rolling with that.

Tobias42 17y ago

> Java is a memory hog Tomcat with a simple app installed uses about 60 MB when it's idle and not much more with dozens of parallel requests. With Rails you need about 40 MB per instance for a very simple application. Edit: And Java is lightning fast. An old project of mine running on a tomcat on a crappy VPS with 192 MB RAM serves the home page in about 100 ms, and without any manual caching, although it executes 7 queries to a postgres-db. A simple rails app which I deployed on a VPS with twice as much RAM takes at least ten times as long to deliver the home page. And the only "dynamic" thing that happens on the home page is the formatting of a date. There is no database involved.

davidw 17y ago
Honest question (I've never done Java web stuff): what does that 60MB actually buy you? Rails gives you a whole lot of tools in that space.
- old-gregg 17y ago
  It's hard to compare but Tomcat is functionally equivalent to something like Passenger, Paster or Mongrel. And last time I looked, it actually ate 80MB. It doesn't make sense to compare empty application servers: it is your running application you should be concerned with. JVM is fine if you're running only a single instance of it: just use threads instead of processes. The problem with JVM is that you often can't afford to have several of them running: in Java world everything is measured in hundreds of megabytes, that's the smallest unit of measurement they use (often supplemented with references to 32GB servers, "they're so cheap now"). Check out Batik Java library for rendering SVG. A single 45Kb SVG file, when fully parsed, eats up 150MB right here on my laptop. After serveral repeated test runs, JVM memory usage grew to a sweet 540MB, where it stopped because I capped it there via -Xmx. For comparison: Inkscape, which is an entire SVG IDE powerhouse, not just a parser, consumes only 3MB more when I open the same file in it, so that's like 50x less, plus it doesn't grow. See, unlike CLR or Python/Perl/Ruby, JVM truly is a virtual computer, i.e. running a WAR file under Tomcat is kind of like running an Office 2008 inside of an invisible VMWare image with Windows pre-configured to occupy either 500MB or 1GB or comparable number. I just don't get why Java people are so damn proud of it. Moreover, they find nothing strange about this bizarre arrangement because they're completely absorbed by that JVM instance. To demonstrate why Java doesn't belong on UNIX I invite you to implement find, grep, less and sort as Java programs, pipe them all together in a bash console and enjoy the show. :-) In the end, there is nothing with Java that can't be dealt with by paying a few extra $ for hosting. The main issue is that JVM is an OS, a much more corporate, boring, uptight and over-engineered (and much less fun) than UNIX is. I also want to address some of Tobias42 comments: for the most part I absolutely agree with him, except I don't follow his comparisons to Rails: we are comparing platforms here, not languages or frameworks. JVM is a memory hog compared to UNIX, and if he wants to compare Rails, I'd recommend loading his Rails app into JVM via JRuby/Tomcat and seeing what happens to his 192MB VPS box. Moreover, I wouldn't call 100ms/page (i.e. just 10 requests/second) "lightning fast", which makes his next comment about "Rails taking 10x longer" sound a bit strange: how hard does one need to try to build a web application with 1 request/second performance?
  - Tobias42 17y ago
umjames 17y ago
192 GB of RAM or 192 GB of disk space?
- Tobias42 17y ago
  192 MB RAM. Sorry, I corrected the typo.

umjames 17y ago

So very true. Since learning Ruby, I've noticed that my attitude towards Java has taken a complete 180. It feels like doing anything in Java is like mowing your lawn with a pair of hand scissors. You can get the job done, but it takes a lot of extra steps/effort when compared to more powerful programming languages. I don't think that the majority of people who are using something else besides Java to build their web app are doing so just because they read some Java-bashing statements on a website. They're either basing their technology choices on prior experience or are just picking something that appeals to them and rolling with that.