mike.mainguy

After spending a considerable amount of time trying to figure out how to refactor some particularly hairly (hairy + gnarly) data access code, I thought I'd share some insight into a popular misconception about what coding to the interface actually means. Let's say we're writing a data access layer and we have something called the UserDAO. a simple implementation might be something like: public class User { public int id; public String name; } public class UserDao { public boolean save(User toBeSaved) { } } I'm going to dodge the issue of the user class not having getters and setters and thus not following the javabean spec and talk about the UserDao Interface. Yes, you heard me, the UserDao class effectively is an interface in this example. Sit down and just think about that for a minute, once you've done that, move to the next paragraph. A great (GREAT) many java developers might not get to this paragraph because they'll imme...

Yesterday I posted a somewhat snarky comment about how You don't need layers until you need them which may have seemed like a nonsensical thing to say. Today I was started to write an example of how to refactor an anemic data model with lots'a layers into a lean and mean persistance machine... but stumbled into a perfect example of what I was trying to say. In essense, I was trying to repeat the idea that "Ya Ain't Gonna Need It" , but with emphasis on the fact that... Yes, you may KNOW you're going to eventually need it, but building infrastructure before you need it accumulates overhead that you must pay for, even if you don't get the benefit. My Example (Snippet of pom file) <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 htt...

I have a couple of quick notes for any aspiring java architects. Please read them carefully and think about them. Adding layers is BAD In general, you don't need extra layers until you need them. At that point, add a new layer (but only in necessary places). Create "standard" layers just adds complexity, makes maintenance more expensive, and ultimately fosters copy/paste coding and discourages developers from thinking about what they're doing. An example of a good time to add a layer is when you need to hide complicated operations behind a facade because low level database transaction management is being done in the same place as the code that determines which screen should be displayed next. Too many developers heard "layers add flexibility/scaleability/whatever" and started adding layers to every situation that has an arbitrary division of responsibility... I've worked on systems where adding a table column to be displayed in a CRUD applicatio...

I recently posted about " Git for Dummies " and noticed that commented that they had followed my instructions and had a strange permission issue. Wanting to verify everything was correct, I did a quick check and, sure enough I was having the same problem. Upon investigation, I discovered that I had posted a which required a public/private key pair and folks who hadn't already set this up on their machines would get an error. The post was supposed to have been written for a new user and they typically wouldn't have done this. As a long time github user, I did this one time setup ages ago and had totally forgotten about it. This is common occurrence, so common, that I give it a name... I call it "Step 0". This is a variation of the curse of (prior) knowledge and can be frustrating for both people trying to learn something new as well as people who are trying to explain how to that something to a newbie. In essence, "Step 0" is the prior knowl...

I'm currently doing an evaluation of Drools to illustrate the differences and similarities between it and JRules. Due to time constraints, most of this is being done on a train commuting between Chicago and my home. This means I'm doing most of my work at 60mph over a 3g connection. This also means that my network is constantly dropping, slowing down, and otherwise misbehaving. So to evaluate drools, I needed to download the 300ish mb zip file and set up. Originally I started downloading to my laptop but realized this was just going to take longer than I really wanted. So, I fired up an ubuntu EC2 AMI, typed "wget http://download.jboss.org/drools/release/5.3.0.Final/guvnor-distribution-5.3.0.Final.zip" and was ready to roll in 5 minutes. An additional benefit to this is that I can point people to the ip address of the EC2 instance and they can actually start to use the product without requiring me or my laptop to be present. An even bigger benefit is that ...