Show HN: Effective java – A tool to explore your Java code written in Clojure

https://github.com/ftomassetti/effectivejava

by ftomassetti • 11 years ago

60 21 11 years ago

rickette• 11 years ago

Looks like a nice side project. But the first question that popped into my mind was, doesn't SonarQube already covers these rules?

austinsharp• 11 years ago

I'm also curious if this offers things Sonar doesn't.

ftomassetti6• 11 years ago

Yes and no. If you consider this as a linter there are many others out there. Most of them in my opinion generate too much noise. I think that effectivejava is useful to explore your codebase, run a few queries and find out some facts about your code: how many utils classes do you have? How many methods are taking more than 5 parameters? You can run easily the queries on the whole project or just some packages and correct your aim as you find facts (for example, you may start asking how many methods take more than 5 parameters and realize they are 1000, then you want probably to start focusing on the methods taking more than 10 parameters. Or you can find that some classes with this problem are generated code and you do not want to consider them).

About the usage as a linter it tries to keep rules to a minimum of sensible rules, the ones explained in Effective Java. We chose them because they are rules well understood and accepted by the vast majority of developers so we hope to reduce the number of questionable findings returned to the user.

speedkills• 11 years ago

This is pretty cool. Are you planning on extending the querying ability at all? I would love to be able to use this like Hoogle, point it at my scala code and query for all methods that take a list and return an int, for example.

jmsguy• 11 years ago

My thoughts too: Sonar, or Checkstyle+PMD+FindBugs, is already ingrained in many of the larger codebases I've worked with.

Of course this is purely anecdotal since I've only worked with +-30 over the years.

dikaiosune3• 11 years ago

I like the aesthetic of using Clojure to fix Java.

lmm• 11 years ago

Small standalone command-line tools are a good place for a language like that, although it's a shame Clojure takes so long to start.

dikaiosune3• 11 years ago

I just recently saw a story about using a pseudo-static compiler to improve the Clojure startup time. Maybe it's about to get better?

film42• 11 years ago

The nice thing about Clojure development is that you really only need to start the JVM once, after that, you can eval anything you need instantly. And really, startup times aren't that bad. Here's Travis CI for a small project I made. Time to start the JVM and run tests? 2.76 seconds. The entire build completes in ~12 seconds.

https://travis-ci.org/film42/rinok#L99

ftomassetti6• 11 years ago

as a workaround we created the interactive mode in effectivejava. Also because parsing tons of files require a lot of work and you probably want avoid redoing it for every query

erichmond• 11 years ago

You're pretty much able to keep REPLs open for days if you wish, so if you amortize that 3 second startup over a week, it's not all that serious.

That said, fair point, faster startup is always better.

ftomassetti6• 11 years ago

Like many, I have fun using Clojure but during the day I have to pay bills by using Java :D

Jokes aside I think that Clojure is fantastic to manipulate data quickly. By the way this project is built on top of Javaparser (https://github.com/javaparser/javaparser) and that is written in Java.

hajims2• 11 years ago

Just tried running it and got this, I'm guessing I'm doing something wrong...?

[me@localhost myapp]$ java -jar effectivejava-0.1.2-SNAPSHOT-standalone.jar -l -d "/home/me/myapp"

Exception in thread "main" java.lang.ExceptionInInitializerError at java.lang.Class.forName0(Native Method)

...

at app.core.<clinit>(Unknown Source)

Caused by: java.lang.NullPointerException

...

Could not find the main class: app.core. Program will exit.

ftomassetti6• 11 years ago

never saw this error but current version is 0.1.3-SNAPSHOT.

The instructions are probably confusing, I will fix them. You can run: lein jar java -jar target/effectivejava-0.1.3-SNAPSHOT.jar and then the options.

Thank you for reporting this!

hajims2• 11 years ago

quick google shows someone else had the same error:

https://www.reddit.com/r/Clojure/comments/31uqab/writing_a_t...

Thank you for this though, hopefully I'll get it working...

Show HN: Effective java – A tool to explore your Java code written in Clojure

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