mike.mainguy

A great many people are competent java developers, but have only a vague understanding of the difference between a "public static method", "public method", and the difference between a class and an object. As this was confusing to me at first, I thought I would give a quick overview. A class defines a template for what data and operations are available when you tell the JVM to create an object. So, for example: public class BlogPost { public String text = ""; public static BlogPost latest; public static BlogPost create(String input) { latest = new BlogPost(); latest.text = input; return latest; } public int getTextSize() { return text.length(); } } When you compile this class, it is creating a file that the java runtime can later use to enable programmers to load an object into memory that has a single attribute called "text" which is a reference to another o...

I don't consider myself a java expert by any measure, but there's a disturbing thing I've noticed. There are a LOT of people who claim to be "java developers", but they have zero clue what the "java collections framework" is. This post is designed for folks who keep getting stumped on interview questions or are mystified when someone starts talking about the difference between a Set and a List (for example). If you google "java collections framework for dummies" you'll find this link which has a more complete, if fairly dense explanation. I'm going to do you one better and give a rule of thumb that you can use without thinking about it. At it the root of things, a collection is something you can store other things inside. Just like in real life, a collection of marbles is just a "bunch" of marbles. The big difference in the collections framework is that the different implementations have different things they DO with t...

While touring a college campus with my daughter, one of her prospective cross country team mates said something that gave me pause. In effect, her statement was that she really liked cross country because everybody on the team was always pushing for you to do your best. Also, she continued, it's nice to know that you either succeeded or failed because of your own effort and training, not because of anyone else. I've thought about this for quite some time and I realize there is a VERY big distinction between "individual" sports like wrestling, swimming, or cross country... and "team" sports like soccer, football, or basketball. These differences are important not just on the playing field, but in any situation that requires teamwork. On "team" sports, you very often will have competition within the team that actually works against the team's objective. Additionally, individual team members may have to forgo performing at ...

Smart technical people (aka Hackers) have likely dedicated thousands, tens of thousands, or hundreds of thousands of hours of their lives learning, understanding, and generally figuring out how things work. If you find yourself asking for help, I'd suggest approaching it like you would approach asking advice from someone like Tony Hawk on how to do a kick-flip (I apologize for folks who don't know who Tony Hawk or Ryan Scheckler are and further apologize if you don't know what a kick-flip is... you really should get out more. I further apologize for suggesting that programming a computer is in any way as difficult as performing a kick-flip, I've skateboarded since I was...like 13 and still cannot pull one off without doing a no-comply, it's just a useful metaphor that non-technical folks might be able to understand. To illustrate some approaches: BAD "Tony, I've never even stood on a skateboard before, but I REALLY want to learn. I've got a spare...

One trend I've noticed with git users is a habit to create a lot of branch and merge activity. The oft-repeated mantra is "branching is (easy/cheap/safe) in git so I do it a lot". When working on an agile project though, this behavior can cause serious problems. To illustrate the point, compare american football to soccer: American football has highly specialized players and positions as well as a variety of tightly choreographed set pieces. In contrast, soccer has a much lesser degree of specialization, and while there are some set pieces that are choreographed, the majority of the game is spent reacting to the situation as it evolves. Traditional development methodologies are like american football: They divide the work up among highly specialized players and then try to replay an intricate set of movements to make the play "work". Agile methodologies are more like soccer (or to a lesser degree rugby) in that the advantage doesn't come from follow...

Waay back in 2003, I got tired of writing the same boilerplate crud apps and longed for a "better way to do things" so I wrote a rapid development framework called thrust . It used turbine, velocity, and torque to build an entire web application scaffold from an xml database schema definition. I look at the code now and kinda chuckle and shake my head, but something I realized is that it predates the public release of ruby on rails by a good six months. Moreover it predates the closest allegory I can find in the java space (Spring Roo) by a good 6-7 years! I'm not just tooting my own horn, because I remember talking to other people who all said things like "we should just use conventions" and "this stuff is just boilerplate, why don't we generate/template it?", but it seems like most folks just built internal-only proprietary solutions. Couple of lessons/observations: #1 promotion is everything... rails languished in relative obscurity un...

Fact: putting a skirt on a Gorilla doesn't make it any more graceful Are your agile initiatives Gorillarinas? If you're working in a large organization and trying to "be agile", it often turns into a strange situation where only a superficial set of changes are made, but folks wonder why their initiative isn't able to deliver the expected benefits. This is remarkably similar to putting a skirt on a Gorilla and then wondering why it isn't suddenly graceful. I'm not saying you cannot train a Gorilla to dance ballet, I'm an optimist at heart and believe anything is possible. But don't make the mistake of thinking that the effort of taking an IT organization that has built up the overhead gunk and crud of a huge process and turning into a highly responsive and lean software delivery organization is anything less difficult than turning a Gorilla into a ballerina. This effort will be large, there will be casualties, and you will likely need ...

How many folks out there are promiscuous programmers? You know who you are, every project you work on, you meet a new technology or language and feel compelled to "try it out"... without giving the right amount of consideration to the language that is currently being used. Worse yet, you seem compelled to badmouth a language that has been really good to you ( I love you java;) ) and always compare the imperfections of your programming wife ( java, you're syntax is really bloated) to the sexy cool stuff from one of your programming girlfriends (ruby, I love your monkey patch). I'm not saying that this is necessarily a bad thing, I think it is very important to have breadth in technology and learning new programming languages is a way to become a better programmer. It's more important though, to have an objective perspective about the REAL comparison and not just get infatuated with every new thing that wanders by because you think (or worse yet someone else th...

I was recently sitting through a technical discussion and was thinking about how different people were reacting to the information in the presentation. From this I started to think about how a two pairs of related factors seem to influence how people react to new technology. Here's a quick chart showing them as well as examples of prototypical statements a person at each extremes in each quadrant might speak about Source Code Control: For a bit of definition: The Conservative - Liberal continuum is a measure how inclined you are to try new technologies. An extreme conservative feels no need to use anything new and will never use anything new unless the old thing completely fails to work any more. An extreme liberal would be compelled to change technological approaches before even finishing a prototype because a new shine technology showed up on their radar. The Skeptic - Believer continuum is a measure of how much critical thinking you put into a new technologies capabil...

I recently had to debug a problem that was causing a javascript function to return the incorrect value. The code in question was right padding numbers less than 10 with a 0: so 1 became "01", 2 becomes "02" and 10 should be "10". Number.prototype.to_s = function() { if (this < 10) { return '0' + this.toString(); } else { return this.toString(); } } This works fine... in one direction. I kept running into a problem when I tried to parse this back into an integer. So I'd do something like parseInt(8.to_s()) and the result would be 0. What I didn't realize is that the "0" prefix when parsing an string indicates the number is base-8 (octal) and therefore "08" isn't a valid number. I would have, however expected some sort of error message or NaN instead of 0. The problem is that javascript will only return NaN if the first character in the string is not a number... so It happily ...

I've used each of these tools on at least one project now (JIRA for quite a few) and thought I would share my observations about when each one would be most appropriate. Pivotal Tracker Pivotal Tracker is only offered as a cloud based or hosted solution, but has a pretty impressive list of customers. On the upside, they've fully embraced the cloud concept and offer a well documented set of RESTful APIs to integrate with third party systems. You can connect issues to SCM commits using post commit hooks from svn or git (or anything with a little effort) I find the pivotal tracker User Interface be a bit confusing, but pretty useable out of the box and geared toward agile methods. Another big plus is that they can auto-estimate your actual velocity and burndown which helps you get your arms around your real velocity. In addition, they have some out of the box reporting. playnice.ly playnice.ly is also a hosted solution, but of the three has taken an more in...

In the current nosql fervor, there is an important distinction that seems to get missed repeatedly. There are two (OK three) really important factors that these tools use to distinguish themselves and many people completely miss the point. The first factor is durability -- does the data actually get saved to a disk somewhere and, if so, how often and how much might I lose if something "goes wrong"? Redis and mongodb users might be somewhat surprised to learn that, by default, they can lose your data should the process crash or shut down. While you can configure them to work around this issue, you're going to slow things down substantially doing so and therefore lose the big advantage they've been designed to provide. In short, redis is a great alternative to something like memcached, but is not really an alternative to something like couchdb. Which brings me to the second factor, which is searchability (I couldn't think of a better term) -- Key-value sto...

After reading the recent blog post by Amazon about their "cloud enabled" browser called silk, I went into a minor panic.  I couldn't find any immediate information about the rendering engine or any technical details about what they actually doing.  After some digging I uncovered some job postings that seem to confirm they are using webkit for their rendering and are leveraging SPDY on the network protocol layer. This is great news for developers as webkit is already well established and most of us won't be immediately impacted by SPDY (well actually, your ajax experience might be impacted, but that's another topic entirely).  All told this isn't as big a technological change at the front end and is more of a story about amazon trying to use their infrastructure to make the mobile browsing experience better.  Frankly, this is a scaled up and modernized version of what blackberry did years ago (are they still doing that?). NOTE to Silk team -- please impl...

Git and most of the workflows I've seen on the internet are not designed (or well thought through) for most agile development.  By agile development I mean a small (1-10) team of professional developers all working together in short cycles (1-3 weeks) delivering functional software. Why is git not designed for agile?  Because git, or more importantly, the workflows most readily apparent on the internet all focus on the idea of isolating changes or playing around with branches instead of getting stuff done .  This is great if you have a benevolent master who's sole job is to integrate disparate changes into a common code base (you know, someone like Linux Torvalds), but awful if you have a team of 10 people hacking away on a common codebase.  Aside from some very epic fails in the cvs and svn designs, git by itself doesn't really help in this situation.  I'd dare to say that git actually gets in the way 3x more than it helps. To make matters worse, if you per...

I've been working on a cross platform mobile application for keeping track of how much time I spend doing things. Basically a consultants helper to make sure I'm spending appropriate amounts of time doing the things that move me forward and keep me aware of how much time I'm spending doing things that aren't going in the right direction. Anyway, having done mobile web development and knowing the pain there, as well as having put together a few android/iOs "hello world" applications, I did NOT want to go down the "build 3 different versions" road. I understand that there are compelling reasons to do this, but there aren't compelling enough to do it (in my situation). Knowing that there are a number of solutions in this space, I narrowed it down to things that seem to have #1 the most innovation and #2 the highest potential to NOT be a dead end career wise. My list was narrowed down to titanium mobile , rhomobile , and phonegap . First off, t...

Anyone using a mac for software development has probably run into the need for some gnu/open source software that isn't pre-packaged. One of the great failings of Mac OSX is it's lack of a real package manager. Luckily, users stepped up and built some solutions: Fink, MacPorts, and HomeBrew. I've never used fink, but I hear it's pretty good. Being also a debian/ubuntu guy, I'm familiar with apt-get so it's probably a decent tool... but having no direct experience with it I can't really comment. This brings me to the two tools I HAVE used: Macports and HomeBrew. I started off with macports because it was the one that had the packages I was looking for. On advice from folks I was working with (I believe the comment was "why are you still using macports, everyone is using homebrew now"). I downloaded and started using HomeBrew, but frankly, I'm unimpressed. As far as I can tell, the only reason anyone would use homebrew is if they stumb...

I recently started a new Rails 3 project and was going to use devise for authentication. While very powerful, the documentation was a touch confusing for me and all the other blog posts kept confusing me. What follows are my steps to get up and running with a minimum of effort and thinking. Step 0, put devise into your Gemfile and run bundle install Next, Generate the devise install scripts $ rails generate devise:install Devise will spit out: create config/initializers/devise.rb create config/locales/devise.en.yml =============================================================================== Some setup you must do manually if you haven't yet: 1. Setup default url options for your specific environment. Here is an example of development environment: config.action_mailer.default_url_options = { :host => 'localhost:3000' } This is a required Rails configuration. In production it must be the actual host of your application 2. Ensure you have defined root_ur...

Looking through cloud literature, it seems we've run out of three letter acronyms (TLA), so we're now using four letter acronyms (FLA?). Chief among these are the "as a service" acronyms which describe what level of stuff is handled by the provider. Wikipidia has some sort of explanation buried in the cloud computing page, but I thought I'd give the abridged version. At the lowest level is "Infrastructure as a Service" (IaaS): You get a virtual server with connectivity to the internet. Examples are Amazon ECS and Rackspace Cloud . In these offerings, you can install almost anything you want (you typically get root access in some manner) and can even install the operating system of your choice. This is a good choice if you're a sysadmin who just doesn't want to muck around with physical hardware. The next level up is "Platform as a Service" (PaaS): You get some sort of development platform hosted remotely and you have a mech...

In ruby 1.8.7, the following works Michael-Mainguys-MacBook-Pro:~ michaelmainguy$ irb ruby-1.8.7-p352 :001 > foo = {"foo","bar"} => {"foo"=>"bar"} ruby-1.8.7-p352 :002 > foo["foo"] => "bar" ruby-1.8.7-p352 :003 > In 1.9.2, it fails rather curiously. Michael-Mainguys-MacBook-Pro:~ michaelmainguy$ irb ruby-1.9.2-p290 :001 > foo = {"foo","bar"} SyntaxError: (irb):1: syntax error, unexpected ',', expecting tASSOC foo = {"foo","bar"} ^ (irb):1: syntax error, unexpected '}', expecting $end from /Users/michaelmainguy/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in ` ' ruby-1.9.2-p290 :002 > Matz/et-al, get it together... this is a pretty significant change and probably warrants a deprecation warning instead of a mysterious fail that in no way indicates what is really happening. This will seriously dampen adoption of th...

My one sentence evaluation: If you MUST use Internet Exploder then Gliffy is your solution, otherwise download Chrome (or other html5 capable browser) and use use Lucid Charts. The long Version: As a long time Visio user, it used to be one of two microsoft tools I missed when working on linux/Mac. Beyond not really working on linux, it's just too damn expensive for the amount of time I spent using it. I'm an occasional user who needs to slap something together that is only slightly more professional than a napkin (although I've used napkins on occasion) or ascii art for illustrating network diagrams or software architectural components. In the last 5 years or so, a couple of online tools have emerged that let you do this inside your web browser. I've used and been a paying customer of both Gliffy and Lucidcharts and will say they are both pretty good tools and if you're someone like me who like me, they can meet your needs. Lucidcharts is a better put...

There are two deployment models: push and pull. In a "Pull" deployment model, the individual servers contact a master server, download their configuration and software, and configure themselves. In a "Push" model, a master server pushes the configuration and software to the individual servers and runs commands remotely. While neither technique is right or wrong, they both have some specific advantages and disadvantages that you should understand when making a decision. In the ruby hosting world, an example of a "push" deployment is heroku , while Engine Yard is an example of a "pull" type deployment. In the Pull model, each server has information about how to obtain it's configuration, when it boots (or whatever the configuration triggering event happens to be) it can continue to proceed without intervention from the master server. In the Push model, because the master server is orchestrating things, it will typically need to have a c...

I read a blog post a while back comparing groupon to a ponzi scheme, but I think it's more accurately Tulip Mania . I discount the value Groupon can have for a business who is missing traffic to their store and struggling to figure out how a business gets a loyal customer from this tactic. As a business, it seems to me Groupon will only create disloyal customers and as a business, the best I can hope for from is a sort of ebay-like place to either dump excess inventory or fill in slow periods where I have trouble getting customers into my place of business. When looking at the fundamentals, Groupon has only overhead. The only arguable asset is their consumer base and I think it provides no intrinsic value as these customers represent a pool of people who will buy something for 50% or more off. I hate to break the bad news, but those people aren't hard to find. Worse yet, the switching cost from groupon to "whatever else" is almost zero. For Groupon to survi...

For folks employed in "traditional" jobs, there is a common event in the modern age that raises collective blood pressure. It's know as "annual enrollment" and it is a period of time where most employees change/adjust various benefits offered by their company. In particular, medical insurance is a common thing to adjust. While this is normal a cost of doing business, I think many folks underestimate the real costs of switching. Sure, there's the cost for the HR department to go out to 20 different brokers and try to get the "cheapest/best" plan for their employees, but there're also a number of hidden costs. For example, every year my health plan changes, I spend at least 5-10 hours futzing around with various billing changes as well as filling out forms etc. When I quote 10 hours, many folks say "you're crazy, it only took me 15 minutes". I think these folks, greatly underestimate the amount of time spent because they...

Engineyard and heroku are two widely used ruby on rails hosting providers. A common question is: Which one should I use? The answer everyone gives: It depends! Having deployed the same application in both environments, I thought I'd highlight some of the important differences. #1 "Ease of Use" Heroku blows engineyard away. you install the gem and can deploy your application in minutes. There are also commands you can run on your local machine to get information about your application. Engineyard is moving forward, but it is still pretty technical. It's really easy if you have a public github repo, but anything other than that starts to get "more complicated" quickly. #2 "Architecture" Engineyard gives you a "real" virtual machine. This means you've actually got a single CPU virutal host that you ssh into and effectively do whatever you want. Heroku gives you a sandbox with walls around it, and I think it's a...

One common theme in the development world is the vast difference in productivity between individual practitioners. Among folks with similar backgrounds, some are easily 10x more productive at delivering functional software. Software development is obviously not alone in having to deal with this, but I there are some particular attributes of software development that make dealing with this mismatch particularly difficult. The first problem is that many people seem to have the mistaken impression that if one has developers who produce output, then the output is simply the sum of the individual outputs. This is just not true by any reasonable measure and is a contributing factor to the reason many outsourcing projects end up a smoldering mess. Mathematically, each developer adds a cumulative amount of drag if the software they are writing needs to communicate with software other folks on the team are writing. As an example, suppose we have 1 developer working on a project, and he h...

We recently noticed some pretty interesting changes in ruby 1.9.2. It appears that require no longer allows relative paths and ruby is now more unicody. This means if you are in a directory with two files "foo.rb" and "bar.rb", you can no longer simply type "require 'foo'" inside bar.rb to use foo. Now, you need to either do "require './foo'" or "require_relative 'foo'". A potentially more difficult change is in how ruby handles character encodings. For the most part, this isn't a problem inside "normal" code and strings, but things get dicey if you start reading text files off a filesystem. This is especially dicey if you're doing this and you're on a mac AND you work with western european data AND it involves money. If you save a file with a currency symbol on a mac, then subsequently read the file on a machine (or a tool) that uses/assumes utf-8, you will not see €, you will see...

I recently stumbled across a problem with git that is going to cause no manner of headache for the uninitiated. Git repositories are fundamentally insecure and the audit trail is dodgy when folks are either #1 intentionally malicious or #2 ignorant to how git works. For the back story, I have a number of github accounts, one is used for code I use while blogging, another is for internal projects at work, and yet another was for a client I was working on. A while back I noticed that I had commits that apparently were done with my "client" github account that showed up in my blog. Confused, I verified my public/private key pairs against what was in github and was truly stumped as to how this was happening. While scratching my head, I remembered that there is the concept of a "global" config in git and ran the following command: git config --global -l Uh oh! it turns out I had a global config set... When I went back and looked, EVERY commit I had done was as...

I just read a great blog post about what it costs to write AAA games and the author used a term I love called " Bowfinger Syndrome ". Bowfinger is a movie starring Steve Martin and Eddie Murphy in which Bobby Bowfinger (Martin) tries to make a movie with only $2000. While a very funny movie, it hits home in the software development world in many ways. Too often, software projects fail because folks grossly underestimate the costs associated and then spend time trying to work around the lack of budget to actually finish the project. There are a number of reasons for this and I'll give a quick list: #1 A prototype of some software was written and someone extrapolates the costs to build the "real software". This is a mistake, prototypes are like hollywood cutout towns... they may LOOK like real software, but they don't necessarily WORK like real software. If you're eyeballing the hours necessary to build a prototype and trying to estimate effort ...

For newcomers to javascript, it might come as a surprise that there is no sleep method. Worse yet, if you search the internet, you'll find all manner of really... really bad ways to simulate this. One of my favorite "rotten tomatoes" is something like this: alert('start'); var date = new Date(); var curDate = null; do { curDate = new Date(); } while(curDate-date Note, I borrowed this horrible example from stack overflow . If you're lucky, that example will not completely crash your browser. A much better solution is something like this: alert('start'); setTimeout(function() {alert('finish')},5000); The obvious problem is that if you truly want to simply pause for 5 seconds in the middle of a really long method, the anonymous function is not going to help you out very much.. unless you do something like this alert('start'); //lots of code var a = 'foo'; setTimeout(function(){ alert(a); ...

OK, the title is a ruse, you can't easily add methods to java classes at runtime. But I'll illustrate how to do it in javascript and ruby. For example, lets supposed we have a javascript object(function) and we want to add a say_hello method to it: var myObj = {}; myObj.say_hello() // doesn't work myObj.say_hello = function() { return "hello"; } myObj.say_hello(); //works This is because javascript treats functions as first class citizens and doesn't even bother with the concept of "classes" as something other than special functions. Same thing in ruby: myObj = Object.new myObj.say_hello # doesn't work def myObj.say_hello "hello" end myObj.say_hello # works There's a subtle difference here. The ruby syntax seems a little strange to me and it wasn't obvious how to do this. In javascript, it's very obvious that you're assigning a new function to the attribute (that you're adding). In ruby, using def in...

Suppose we need to create a counter that starts at zero, increments to 4 and then restarts at 0 (A "you can't count to five" counter). There many ways to do this, but a straightforward way someone might do this in javascript would be: var global_count = 0; function increment() { global_count ++; if (global_count > 4) { global_count = 0; } } This is pretty common for beginners and works until your systems start to get complicated and your global_count gets clobbered or multiple people need to have counters. For multiple counters, one might start with a naming convention and add variables like "global_count2, global_count3" and et cetera. This doesn't solve the problem of the variables getting clobbered in other parts of your system and it likely makes it worse because now there are more permutations to mix up and accidentally change the value of. As an example of what I'm talking about var global_count = 0; function increme...

OK, the title of this post is a lie... git is decidedly NOT for dummies. Git is more for your really smart mentally gifted people OR for people who are working on exceeding complex software projects that have complicate merging and revision history requirements. Neither of these groups should be dummies or you will have a serious problem being effective. For the context of this tutorial, a "dummy" is defined as somebody who knows and understands how to use SVN or CVS in a team environment. So if you're still reading, I will walk you through the simplest workflow I can discover for git that work and doesn't cause too many complications. For the sake of simplicity, we're going to assume you're working on a project hosted at github that already exists. I've created a public repo if you'd like to try along at home. Assuming you already have git installed, you should be able to "clone" the repository to your local machine by issuing the ...