- Maven Polyglot: replacing pom.xml with Clojure, Scala, or Groovy Script shows how you can, well, replace the XML configuration for a Maven project with a configuration in another language. This also provides some imperative-ish features to Maven projects, plus no XML except for a short description of the scripting language.
- How does a relational database work provides a (very) high level description of how a relational database does its work – and if you read carefully you can see some of the motivations behind some of the less- or non-relational database decisions out there, too.
- From user DerDingens: An Examination of Ineffective Certificate Pinning Implementations, which points out common mistakes while using certificates in Java.
- Maldivia pointed out a Java Enhancement Process draft, for Epsilon GC: The Arbitrarily Low Overhead Garbage (Non-)Collector – basically a garbage collector for Java that does absolutely nothing, for the purposes of tuning, testing, and in some cases, performance enhancements (if you know your job is short-lived, why bother running a GC if you don’t need to?) Fascinating stuff.
- From cheeser: Google, IBM back new open source graph database project, JanusGraph. JanusGraph is a fork of Titan, but its list of backers make it worth watching. Have you used a graph database before? How? What did you think of it?
- Two from DZone on git:
- Lesser Known Git Commands has some handy shortcuts for git users (and chances are good that if you’re reading this, you’re a git user.)
- Git Submodules: Core Concept, Workflows, And Tips. From the article: “Including submodules as part of your Git development allows you to include other projects in your codebase, keeping their history separate but synchronized with yours.” Great stuff.
- From DZone: Distributed Systems Done Right: Embracing the Actor Model is a reference to a webinar (ugh, “webinar”) from Lightbend on, well, the Actor Model, a way of representing distributed services. Powerful model, even if you don’t use Actors as described.
- TwelveMonkeys is a set of additional plug-ins and extensions for Java’s ImageIO. It includes BMP, TIFF, JPEG, PNM, and a few others.
- From user u1dzer0: Awesome Asciidoctor: Include Partial Parts from Code Samples describes how AsciiDoctor can extract, well, partial code samples from a block of code. Given Java’s verbosity (not a bad thing, but a still thing that many people don’t like), having a way to ignore code can help focus on relevance. (Also see: Dexy.)
- The Deadly Diamond Of Death In Java 9â€™s Module System discusses a problem Java 9 has with automatic modules, when a dependency has two names but one resolution path. (Confused? Read the article – it describes it better than I do, but at much more length.)
An Aside About Scala
A mailing list that was pretty popular back in the day recently had some activity asking about Java 8. The discussion itself was a little bit interesting, including a reference here and there to other languages… like Scala. Kirk Pepperdine wrote a post that absolutely riveted Your Humble Author, and may have actually convinced him to stop bothering with Scala except where absolutely necessary. I’d like to quote it here, since Yahoo!’s web page formats things poorly sometimes:
I personally donâ€™t feel that Scala offers any advantages over Java. If you take away the opinions on style, Iâ€™d argue that moving to Scala actually leaves you at a slight disadvantage. First, point, the JVM support for languages other than Java was quite poor until Nashorn. Nashorn was actually 2 separate projects. One to get JS running in the JVM and the second was to refactor the JVM to isolate the APIs needed to support alternate languages. Scala hasnâ€™t been able to take advantage of those changes as of yet and Iâ€™m not sure they are interested in doing so. Next is tool support. The Java tooling chain is and remains quite broken in 8. I fear that this situation will get slightly better in 9 but then changes there will batter the tooling china quite badly. Unless the Scala people step up to the plate (and there is no evidence of them doing so to date), the dismal state of the tooling chain in Scala will continue to get worse. I currently see very little motivation for companies to invest in the work needed to improve the tooling in Scala. Though I see that this might change, every time Iâ€™ve previously thought it might get better, something in the market changes and Scala takes a hit and things donâ€™t get better so my track record on predicting this is admittedly very poor. But then Iâ€™m predicting improvements in this area and theyâ€™ve simply not happened.
What makes me more hopeful is that I know of a couple of very big projects running in stealth that are based on Scala. These projects are big enough that theyâ€™ve really been hurt by the weak tooling story in Scala and I imagine or can only hope that they will start to look at fixing the problems they are facing. Many of these problems are baked into the JVM so to fix them, we need to further fix the JVMâ€™s support for alternate languages. The feeling I get coming from some JVM developers is that itâ€™s the JVM that is past EOL. Maybe Graal will be the thing that replaced HotSpotâ€¦ not sureâ€¦ all I know is that the JVM is past due for a huge refactoring and simply donâ€™t see anyone.. certainly not Oracle funding that effort.
I’ve “played”with the new features and to be honest find the Scala implementations cleaner and easier to write and understand.
To say that Scala is less verbose than Java maybe true in the small but Iâ€™ve found it not to be so true in the large. Reachability in a language is very important and deserved or not, Scala as the reputation of not being so reachable and hence not so readable. IME, almost everyone one I know struggles with the readability of Scala even those that have been using it for quite some time. This is not to say that Scala code canâ€™t be read, itâ€™s simply that Scala code not naturally easily readable and hence people struggle with it.
I think we had the same types of problems with Smalltalk. People resisted Smalltalk for some of the same reasons and in cases where C/C++ wasnâ€™t so desirable we saw teams jumping to Java. In this era I think the current alternative to Java is Go. The buzz around Go is more marketing and hubris than reality but it has a buzz and level of activity that feels familiar to the buzz that we say with Java in itâ€™s early days. Just like people kicked the tires and sniff around Smalltalk and then moved on, I get the same sense here with Scala.
Java is starting to give under its own weight of patched-on features, IMHO.
On the contrary, I think that Brian has done a wonderful job integrating Streams and Lambdaâ€™s into Java. The only thing I can complain about that makes things a wee bit difficult is this aversion to mutable state. Fine if you donâ€™t like mutable state but that streams make the mutable/immutable decision is an overreach on Brianâ€™s part. It disallows a valid model that we need to work in. Itâ€™s different than how everything else works in the language. Streams are inherently single threaded and thus concurrent modification of state is a concern that lies outside the internals of a Lambda expression. IOW, Java != Scala in that Scala had immutability baked into (just about) everything right from the beginning. Brian did consider these points when he designed Lambdas and he opted for his bias towards immutability.. so be it.. All I know if that Lambdaâ€™s do not feel like they are patched on to me. They feel like a natural part of the languageâ€¦ much better than the earlier proposals that were tabled. The work on ValueTypes and type inference is also focusing on making sure that the added features do not feel like bolted on bits and that they fit naturally into the current language. Brianâ€™s idea was to create small changes in the language that have a huge impact on your code. While I donâ€™t agree with all of his choices I do think heâ€™s done a brilliant job.
- Life hack: Look before you paste because people can hide content from rendering in the browser. Pasting content to a command line can do some unexpected things. (From cheeser.)
- From whaley, who’s been on fire lately: Recipe for a great programmer. Great reading.
- More from cheeser, who is also on fire: InfoQ’s reference to Chaperone – A Kafka Auditing Tool from the Uber Engineering Team. If you’ve ever struggled with how visible Kafka information can be – i.e., you’re a Kafka user – any promise of improvement is a blessing.
- Compilation of Java code on the fly shows a highly dangerous and insecure feature that people have known about – but as said, it can be a security nightmare. Use with lots of caution, or don’t use at all – but it’s there.