We’re hosting a chamber music recital on Friday, September 4, 2015, 7:30 p.m. at Tates Creek Presbyterian Church. I’ll be performing with a number of other friends, with music including Dvořák’s “American” Quartet and York Bowen’s Fantasie Quartet for four violas. We’ll also be premiering a piece I just finished, Fairy Tales for four violas. The title is reminiscent of Schumann’s Märchenbilder.
My wife and I attended the NABC bridge tournament in Chicago last week. We had a great time. On on our fourth and final day, we entered an event called “Gold Rush Pairs”, which included a moderately strong field (no pros) with 81 pairs. We finished first overall (top of page 12)! It’s one of our strongest tournament games yet. We’re improving!
I recently entered the Rapido! Composition Contest. They have an interesting condition: the piece submitted must be written during a two-week period that the contest is open. The first day, they email contestants the constraints for the piece. This year, the requirement is a 4-6 minute theme and variations for violin, clarinet, and piano. I composed furiously for two weeks and finished a piece that I am very happy with. Now I’m back to working on a quartet for four violas, which I hope to premiere in September.
I recently discovered some awesome tools for creating synthesized sounds. The sounds they generate are just like the sort of things you hear in an 8-bit Nintendo game.
First there is BFXR. You can easily get started by clicking the presets on the left. They aren’t “fixed” presets, but rather random distributions, so if you click “Explosion” repeatedly it generates several sounds that resemble explosions. Then you can manipulate the various synthesis parameters. The “Mutation” button jiggles the parameters a little bit. Way cool!
Then I found LabChirp, another fun tool with a similar purpose. LapChirp focuses on layering several synthesized shapes. It’s not quite as freakishly easy to use as BFXR, but it’s powerful and it also has a randomizer function to help you get going.
Two great programs for creating new sounds for your next homemade video game!
As I’ve built out several applications in Java and Scala, I’ve spent time musing on and researching different approaches to package structure.
The two main approaches are “package by layer” and “package by feature”. These are exclusive in the sense that you have do one of them first, at the top level of your structure, though you can do the other at a lower level.
Package by layer
Package by feature
Like many architecture discussions, things can tend to get a little religious. We’re talking about a strategy for breaking down a very large and complex problem; it’s actually viable to do either one. But I do think that in general, package by layer is a preferable approach. Here are some of the better references I found:
Package by feature: http://www.javapractices.com/topic/TopicAction.do?Id=205 and http://shaunchilders.com/node/15
The main reason I prefer package by layer is this: layers are fundamental to most architectures, and package by layer puts the core architectural division at the first level. I agree with “Directory structure is fundamental to your code” section in the “javapractices.com” site that the “first strokes” are important. But I disagree that the fundamental division is features rather than layers. That article says, “The fundamental flaw with package-by-layer style, on the other hand, is that it puts implementation details ahead of high level abstractions…” I think this is misleading. Someone looking at the codebase is already interested in the “implementation details” of how it is constructed. I use apologetic quotes because we are talking about the highest-level architectural decisions, so calling them “details” seems like a hand-waving way of dismissing the structure of the software. Abstractions let us divide a problem into manageable parts. Dividing a problem into mostly-independent, loosely-coupled layers is a common first step in architecture, and I think it is much more fundamental than dividing an application into features.
Features tend to come and go much more quickly than layers. Over time, the most stable part of the software architecture is likely to be the division of layers, so that should be the top-level structural division. The division is so deep that some features may not map 1-1 with features in other layers: you may have several UI components per model component, or vice versa. It is very likely that there are fewer layers than features. And finally, specific layers are common to many software applications: you are very likely to see something like “model” and “UI” layers in most applications; by contrast, features are completely dependent on the domain. If I know very little about the project structure, and I’m looking at the project for the first time, I think it is more likely that I can find what I need if the top-level division is similar to other applications. Once I’m more familiar with the application, I probably know something about each of the layers, but I may not have touched some of the features.
So while it may not be appropriate for every application, my tendency is to prefer package by layer, unless I have a compelling reason to do something else.
Launched Sebastian, the ear training tutor!
Trying to deploy my JavaFX application on Mac has been incredibly frustrating. But this is no accident. In fact, it is a direct result of Apple’s software philosophy. Specifically, Apple wants a couple of things: 1) to have 100% iron-fisted control of the whole Apple-branded technology stack and 2) to shift 100% of the pain of software problems from users to developers. You can’t argue that their philosophy has been successful in some sense—just check their stock price.
On the other hand, they have chosen to make life much more difficult for developers than necessary—especially Java developers. I’ll give a few concrete examples.
One of the most egregious examples of Apple’s software philosophy is how their products handle errors. The general idea seems to be to hide any remotely scary-sounding error message from the user. Back in the day, Windows was infamous for its “blue screen of death” (BSoD), an iconic example of the frightening error message. Now you tend to get more friendly, but still tech-arcane error messages on Windows. At least the user (or a developer) can do a quick web search for an error message and usually find the cause and/or solution. By contrast, Mac OS X tries to either hide the error and pretend like nothing happened (even if it means, your application appears to hang for no reason), or worse, give an outright lie as the message. For example, an application that is “improperly” digitally signed may generate a message saying that the application file is corrupted, and the user should try downloading it again. Heaven forbid we mention anything that might disturb the user like an untrusted cryptographic signature.
Signing an application with a well-known, trusted authority using a standard process is not enough for a Mac application. Instead, with the new Gatekeeper features, you need to sign your application using Apple’s process and Apple’s certificate, which they will happily sell you for $99 (no concern for the small-time developer who might not want to shell out $99 for a hobby project). If your application doesn’t jump through all of Apple’s hoops, the user might get anything from silent failure to an indication of a corrupted file.
Oracle is not blameless either. They should have made it a priority a long time ago to streamline deployment of rich client applications on any supported platform. The Java Web Start user experience is a travesty. Due to security issues, vendors like Apple and Mozilla have gone out of their way to make it difficult to run any Java applications. The result is a terrible user experience for launching Java-based applications, especially on Mac OS X. Worse yet, recent “bug fix” updates to Java 7 actually break some Web Start applications in the name of security.
But all is not lost. Enter JWrapper, a free and awesome solution for deploying Java apps as native applications on Windows, Mac, and Linux. Like other commercial solutions, JWrapper builds native installers that work regardless of any JRE being present. Unlike other solutions, JWrapper doesn’t cost thousands of dollars… in fact, the basic version (with a JWrapper logo) is free, and the paid license is only a few hundred dollars. Rock on!
I still had some trouble working out a few deployment kinks. In particular, I had to include a magical JVM option “-Djavafx.macosx.embedded=true” to get JavaFX to run properly and consistently in a Java 7 + Mac environment. But the build process is relatively simple, and now my application runs on a Mac with a good installation user experience. You plug in the code certificate files and it signs your application both in the standard process and the Mac signature process. I highly recommend JWrapper for developers of Java GUI applications.
What’s this?! We live in a crazy world where you can download the complete organ works of J.S. Bach for free, thanks to Professor James Kibbie: http://www.blockmrecords.org/bach/download.htm
So Oracle has been steadily tightening the screws on Java security due to all the bad press recently. The latest version of Java suggests that they might block all unsigned applications in the future. I find this “nanny” approach to running code to be kind of annoying; shouldn’t I decide what code to execute on my own computer? Anyway, authors of Java Web Start applications need a cheap way to sign code. Quick searches and StackOverflow suggest a few alternatives. Here I’ll quickly mention two that I tried.
StartSSL is a small business from Israel that wants to end the protection racket known as “certificate authorities” (CAs). They charge you a reasonable price for the actual work they do (i.e. validating your identity), then let you create as many types of certificates as you need. Their SSL certificates are fine, and you can even get those for free. They advertise code/object signing certificates if you pay for identity validation, and several blog and forum posts indicate that you can use their certificates to sign Java applications. Their website says nothing to the contrary. But, unfortunately, you can’t. Long story short, I paid for identity validation and found out after the fact that StartSSL certificates are not trusted by Java and the company does not support Java code signing (from direct email correspondence). Too bad, I really wanted to like them. Ugh.
Back to the drawing board. Comodo offers code signing certificates that are trusted by Java. They also have a bunch of resellers that sell the certificates at “reasonable” prices (reasonable relative to the “brand name” CAs). I bought a certificate through KSoftware. They want a bunch of random stuff after you pay for it, like they want you to update your phone number in some online directory (’cause no identity thief could ever do that?!), but overall it was a fast and good experience. And most importantly, the KSoftware / Comodo certificate works and is relatively cheap, currently less than $100 per year. Some CAs charge five or six times that much.
The certificate gets magically installed in your browser. (I used Chrome.) You then export the certificate, making sure to “include the private key”, to a .pfx file. Java’s keytool can convert the .pfx file to a Java keystore:
keytool -importkeystore -srckeystore theCertYouBoughtIncludingPrivateKey.pfx -srcstoretype pkcs12 -destkeystore yourShinyNewJavaKeystore.jks -deststoretype JKS
Then use the jarsigner tool to sign your jar file during your automated build process. Note that the “alias” in the keystore will be a long string of letters and numbers with hyphens.