1

I am not sure if the title of the question is correct, but please read the question.

I have been working on C/C++ for most part of my work life (close to 11 years). we only had C/C++ source/header files and all dependencies were managed by Makefiles. things were simple and manageable.

for the last 1.5 years i have shifted to Java domain. and i feel extremely irritated that most difficult aspect of working with anything new is the dependency managers. e.g. maven, leiningen, builder, sbt, etc etc etc.

whenever i download anything new from the open source world, there is a significant amount of time to be spent to just to setup the compilation, build, run environment. that too when i am using eclipse. why can't all the dependencies be placed along with the software to be downloaded?? why the tools like maven,leiningen, etc must make a separate internet connection to download the dependencies. i know that maven forms a local repository and should be able to find the dependency locally as it downloads whole internet anyway, but why is this model used. I am behind a firewall and not everything is accessible, and the tools fail to download dependencies. i am sure the same situation is there in most work environments.

recently i started with clojure, and boy it has been a pain to get eclipse configured for clojure. leiningen is supposed to be some magic which must be used with any clojure development. sometimes it feels learning leiningen is more important than learning concepts of clojure. i downloaded so called 'standalone' jar file for leiningen as 'self-install' was not working for me. but it fooled me. as soon as i run 'lein' command it is making an internet connection and trying to download somethings. WHY? it wont even print the help menu without connecting with the internet. WHY? there is no way i can fulfill its demands without bypassing my internet firewall, as i dont know, and no one can tell me what all things this guy wants. there is simply no other way.

And every one seems to be inventing their own. Java had ant which was simple, and went to Maven, some project uses Ruby based Builder, Clojure has leiningen, Scala has sbt. Go has something else. WHY? Why we need this added complexity in a world already full of complexity. why cant there be just one tool.

All you experts in Java technology please excuse my rant. I am sure this question will be downvoted and closed as from someone who is not trying hard enough to understand the things. But please believe me i have spend enough hours battling with this unnecessary complexity.

I just want to know how others get around this, or am i the only unfortunate one facing these issues.

weima
  • 4,653
  • 6
  • 34
  • 55
  • 4
    "I am sure this question will be downvoted and closed as from someone who is not trying hard enough to understand the things". We answer concrete questions. I am sure it is painful, but you need to format your questions into something that can have a chance at being answered. This, cannot. – Dmytro Mar 06 '13 at 10:05
  • question is why do we need this complex dependency management and am i the only one facing these issues. If others are facing these issues, can something be done about this. Thanks for your comment. – weima Mar 06 '13 at 10:13
  • There are a lot of problems that something can be done about, but too many to do something about. For instance, C++ spits out garbage if you try to std::cout << string without including . Again, this is more of a philosophical question, complexity is here to stay. – Dmytro Mar 06 '13 at 10:15
  • agreed. but do others face this problem? do you face this problem? if yes can you help me with understanding dep mgmt in general? and maven or leiningen in particular? Thanks. – weima Mar 06 '13 at 10:18
  • Sorry, I misunderstood the question, I spend several hours researching dependency managers and still fail to understand their purpose. I am a minimalist, and I know from the little experience I have that you can manage dependencies with simple build scripts and strong assertions on target systems. – Dmytro Mar 06 '13 at 19:51
  • 2
    You don't understand the purpose of transitive dependency management? I find that impossible to believe. Any non-trivial project with even a few top-level dependencies becomes a maintenance nightmare as soon as you try to upgrade anything. Doing this manually is a nightmare. – Dave Newton Mar 07 '13 at 18:47

1 Answers1

3

I guess this question cannot accept an answer. I humbly can provide you with elements, hopefully they will help you get some perspective on the problem.

There are mainly 2 problems I identify with Java build systems:

  • some of them are declarative while others are using scripts
  • the fragmentation of the Java tools for building and exercising control is tied to people and Java stewardship of the space, not so much the technological choices.

Maven is the paramount of a method of defining your build using a formal grammar in a standard manner. Your pom.xml file contains a lot more than just your build : it is the identity of your artifacts, the project metadata, the modules and the plugins brought in. It treats with particular attention of the declaration of the dependencies and repositories. Maven is declarative.

For a certain population of programmers, this is great, and they don't create new projects very often. It works well over time, it consolidates the build nicely.

Ant is a different system where you define tasks that will execute, chained in a particular order. All the definitions are made using XML and in effect, you are writing scripts and declaring how they will be stitched together.

Buildr (full disclosure: I am a committer there) is a build system which was created off the frustration of dealing with the inefficiency of the declarative approach for cases where the build needed to do additional steps and complex testing and the rigidity of using XML for a build. It is script-based, enforcing conventions over configuration (expecting a few good defaults, but letting you drive if you need to change things).

I am not familiar with Gradle and SBT but I think they extend and build on this approach, from what I heard.

So this gives you I hope a better picture of the landscape in terms of build tools.

The reason why no standard build tool emerged is probably tied to the fact Sun didn't push one with Java. Eventually, I think they adopted Ant (I have some most JSR jars being built with it). There also has been some products built in this space over extending some of those build systems ; there is always going to be a huge difference between people being paid to maintain code rather than doing it on the side.

And well, people argue. Build systems are a great way to start a flame war. We have a hard time agreeing on a standard though some of the common elements are now settling well around the Maven artifacts.

As for the need to download the Internet over and over again, it's a rather long story but here are a few things that may trigger the need for an unnecessary download:

  • any of the dependencies using SNAPSHOT will try to get the latest snapshot. This is a great scheme but it takes its toll. You might depend on something that depends on a snapshot, and get a download because of that.

  • Maven doesn't redownload the artifacts but sometimes checks md5. This is easy to fix, just use the -O option from the command line.

Tools like Buildr were built around fixing this issue once for all. First off, you only download what you said you would. Second, no connection is made again unless you asked for it. By default, Buildr doesn't play the transitive dependencies game though you can ask for it, but you have to do it explicitly.

I hope this was informative and that your journey in Java land becomes less painful going forward.

Antoine Toulme
  • 937
  • 4
  • 15