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Powered by:
newtelligence dasBlog 1.9.7067.0
The opinions expressed herein are my own personal opinions and do not represent
my employer's view in any way.
© Copyright
2008
,
Ted Neward
E-mail
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 Friday, March 03, 2006
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Don't fall prey to the latest social engineering attack
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My father, whom I've often used (somewhat disparagingly...) as an example of the classic "power user", meaning "he-thinks-he-knows-what-he's-doing-but-usually-ends-up-needing-me-to-fix-his-computer-afterwards" (sorry Dad, but it's true...), often forwards me emails that turn out to be one hoax or another. This time, though, he found a winner--he sent me this article, warning against the latest caller identity scam: this time, they call claiming to be clerks of the local court, threatening that because the victim hasn't reported in for jury duty, arrest warrants have been issued. When the victim protests, the "clerk" asks for confidential info to verify the records. Highly credible attack, if you ask me.
Net result (from the article):
- Court workers will not telephone to say you've missed jury duty or that they are assembling juries and need to pre-screen those who might be selected to serve on them, so dismiss as fraudulent phones call of this nature. About the only time you would hear by telephone (rather than by mail) about anything having to do with jury service would be after you have mailed back your completed questionnaire, and even then only rarely.
- Do not give out bank account, social security, or credit card numbers over the phone if you didn't initiate the call, whether it be to someone trying to sell you something or to someone who claims to be from a bank or government department. If such callers insist upon "verifying" such information with you, have them read the data to you from their notes, with you saying yea or nay to it rather than the other way around.
- Examine your credit card and bank account statements every month, keeping an eye peeled for unauthorized charges. Immediately challenge items you did not approve.
In other words, don't assume the voice on the other end of the phone is actually who they say they are. I think it's fairly reasonable to ask to speak to a supervisor or ask for a phone # to call back on after you've "assembled the appropriate records" and what-not. Who knows? Some scammers might even be dumb enough to give you the phone # back, and then it's "Hello, Police...?", baby....
Remember, it's always acceptable to ask for verification of THEIR identity if they're asking for confidential information. And most credible organizations are taking great pains to not ask for that information over the phone in the first place. Practice the same discretion over the phone that you would over IM or email; the phone can be just as anonymous as the Internet can.
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 Thursday, March 02, 2006
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Scala reactions
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Apparently, I touched a nerve with that last post; predictably, people started counting the keystrokes and missing my point. For example, Mark Blomsma wrote:
Looks to me like you're comparing apples and pears.
C# does not force you to use accessors. The following is already a lot closer to Scala.
public class Person
{
public string firstName; public string lastName; public Person spouse;
public Person(string fn, string ln, Person s)
{
firstName = fn; lastName = ln; spouse = s;
}
public Person(string fn, string ln) : this(gn, ln, null) { }
public string Introduction()
{
return "Hi, my name is " + firstName + " " + lastName +
(spouse != null ?
" and this is my spouse, " + spouse.firstName + " " + spouse.lastName + "." :
".");
}
}
This is only 356 keystrokes, compared to 287 for Scala. Now in Scala the default accessor for classes and members seems to be public, if this were not the case then you'd need 323 keystrokes in Scala.
Only a very minor difference. And definately not enough to make a case that Scala is more efficient for a developer.
Another consideration if you start talking keystrokes is that the tooling suddenly becomes a factor. With C# and VS2005 I only type 'prop,tab,tab' and then the type and name info. Skipping quite some keystrokes.
Mark, with all due respect, I gotta admit to believing that you're doing the apples-to-pears comparison here, at least with your definition of the Person class in C#. The Scala implementation does NOT define a public field, but accessor methods, thus preserving encapsulation in the same way that the property methods do in C# and Java and C++. The thing is, Scala just realizes that 80% of those methods are always coded the same way, so it assumes a default implementation when it sees that syntax. (Ruby does the same thing.)
All that sort of misses the point, though: the purpose of the comparison was not to count keystrokes, per se, but to look at the expressiveness of the language and how concisely the language can express a concept without requiring a great deal of scaffolding. C, for example, could always be used to build object-oriented systems... but you had a lot of work to do on your own to do it. As a result, a huge amount of complexity was spent in manaing the relationships between "classes" by hand (by tracking pointer relationships and so on). C++ solved a lot of that by baking those concepts in as a first-class concept, thus reducing the surface area requirment in the programmer's mind devoted to "plumbing", and making room for more business-level complexity. Java did the same to C++ by introducing GC and other VM-level support, and so on. Scala and Ruby (and other hybrid and/or dynamic languages) are now seeking to do the same to Java and .NET.
The question of tooling is an interesting one, though: is a language just the language by itself, or the language plus the tools that support it? Is Lisp still Lisp if you take Emacs out of the equation? Or is Smalltalk interesting without the Smalltalk environment and/or browser? Can we separate the two? Should we? That's a question to which I don't have an easy answer.
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Scala pt 2: Brevity
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While speaking at a conference in the .NET space (the patterns & practices Summit, to be precise), Rocky Lhotka once offered an interesting benchmark for language productivity, a variation on the kLOC metric, what I would suggest is the "CLOC" idea: how many lines of code required to express a concept. (Or, since we could argue over formatting and style until the cows come home, how many keystrokes rather than lines of code.)
Let's start with a simple comparison. The basic concept we want to express is that of a domain object type, my favorite example, that of a Person type. In domain lingo,
A Person has a first name, a last name, and a spouse. Persons always have a first and last name, but may not have a spouse. Persons know how to say hi, by introducing themselves and their spouse. which, as domain logic goes, is pretty simple and lame, but serves to highlight the metric pretty effectively.
In Java, we express this class like so: public class Person
{
private String lastName;
private String firstName;
private Person spouse;
public Person(String fn, String ln, Person s)
{
lastName = ln; firstName = fn; spouse = s;
}
public Person(String fn, String ln)
{
this(fn, ln, null);
}
public String getFirstName()
{
return firstName;
}
public String getLastName()
{
return lastName;
}
public Person getSpouse()
{
return spouse;
}
public void setSpouse(Person p)
{
spouse = p;
// We ignore sticky questions of reflexivity and
// changing last names in this method for simplicity
}
public String introduction()
{
return "Hi, my name is " + firstName + " " + lastName +
(spouse != null ?
" and this is my spouse, " + spouse.firstName + " " + spouse.lastName + "." :
".");
}
}
Relatively verbose, and while I'm certain people will stand up and argue that any modern IDE can code-generate some of this basic scaffolding for you, the fact is that the language itself requires this much degree of verbosity in order to express the concept. And this is a fairly basic concept; consider a much more complex domain object that has dozens of attributes associated with it. Code-generation and templates can mitigate some of the pain, but it can't remove it entirely, unfortunately.
This isn't just a Java problem; the C# version of this type isn't much better: public class Person
{
private string lastName;
private string firstName;
private Person spouse;
public Person(string fn, string ln, Person s)
{
lastName = ln; firstName = fn; spouse = s;
}
public Person(string fn, string ln)
: this(fn, ln, null)
{
}
public string FirstName
{
get { return firstName; }
set { firstName = value; }
}
public string LastName
{
get { return lastName; }
}
public Person Spouse
{
get { return spouse; }
set { spouse = value; }
}
public string Introduction()
{
return "Hi, my name is " + firstName + " " + lastName +
(spouse != null ?
" and this is my spouse, " + spouse.firstName + " " + spouse.lastName + "." :
".");
}
}
and the Visual Basic version arguably gets even worse since VB prefers to use keywords to symbols: Class Person
Dim _FirstName As String
Dim _LastName As String
Dim _Spouse As Person
Public Sub New(ByVal FirstName As String, ByVal LastName As String, ByVal Spouse As Person)
Me._LastName = LastName
Me._FirstName = FirstName
Me._Spouse = Spouse
End Sub
Public Sub New(ByVal FirstName As String, ByVal LastName As String)
Me.New(FirstName, LastName, Nothing)
End Sub
Public ReadOnly Property LastName() As String
Get
Return _LastName
End Get
End Property
Public Property FirstName() As String
Get
Return _FirstName
End Get
Set (ByVal Value As String)
Me._FirstName = Value
End Set
End Property
Public Property Spouse() As String
Get
Return _Spouse
End Get
Set (ByVal Value As Person)
Me._Spouse = Value
End Set
End Property
Public Function Introduction As String
Dim temp As String
temp = "Hi, my name is " & _FirstName & " " & _LastName
If _Spouse <> Nothing Then
temp = temp & " and this is my spouse, " & _Spouse.FirstName() & " " & _Spouse.LastName() & "."
Else
temp = temp & "."
End If
Return temp
End Function
End Class
A lot of what makes Ruby interesting to people is the fact that Ruby makes this a lot simpler (and I'll bet my Ruby here isn't the most terse it could be): class Person
def initialize(firstname, lastname, spouse = null)
@firstname = firstname
@lastname = lastname
@spouse = spouse
end
attr_reader :lastName
attr_writer :firstName, :spouse
def introduction
if spouse == nil
"Hello, my name is #{firstName} #{lastName}"
else
"Hello, my name is #{firstName} #{lastName} and this is my spouse, #{spouse.firstName} #{spouse.lastName}"
end
end
end
Scala, similarly, simplifies the definition of the type. Take a look: class Person(ln : String, fn : String, s : Person)
{
def lastName = ln;
def firstName = fn;
def spouse = s;
def this(ln : String, fn : String) = { this(ln, fn, null); }
def introduction() : String =
return "Hi, my name is " + firstName + " " + lastName +
(if (spouse != null) " and this is my spouse, " + spouse.firstName + " " + spouse.lastName + "."
else ".");
}
There's a couple of things to notice here. First off, like Ruby, Scala defines the backing store for a field and simple accessor around those fields; note that since this is a functional language, Scala assumes immutable objects by default, so there are no mutators. (It turns out to be fairly trivial to write a mutator method to set the state of those attributes, but that starts to wander away from the intent of functional languages; this is clearly a difference between Scala and a more traditional O-O language like Java or C#.) You may be curious to know where the three-argument constructor went; as it turns out, it's considered the "primary constructor", and is defined in the same line as the class declaration itself. The only reason we need the "this" method (another constructor) is because of the domain rule that says we can have a Person with no spouse.
This is hardly an exhaustive comparison of the languages, but it does give you a little taste of Scala's object flavor. Ruby's syntax is arguably of the same length as Scala's (and frankly, to my mind, they're too close to call... or care), but clearly Scala's length is much much smaller than that of the equivalent C#, Java, Visual Basic or C++ class. (C++ could make things interesting with judicious use of templates to handle backing store, accessor and mutator, but that's considered too advanced by many C++ devs, and therefore too obscure to use in common practice, rightly or wrongly.)
When next we look at this, we'll look at what Scala means when they say "everything's an object"... and how that, in many ways, this means that Scala is more object-oriented than Java itself.
Update: Glenn Vanderburg pointed out that my Ruby wasn't quite correct, and also suggested a bit more "Rubification": class Person
def initialize(firstname, lastname, spouse = null)
@firstname, @lastname, @spouse = firstname, lastname, spouse
end
attr_reader :lastName
attr_accessor :firstName, :spouse # attr_writer *just* makes a writer. You really want this.
# I would typically use the more explicit "if" that you used here, but for terseness I've
# put this in the form you used with the Scala version:
def introduction
"Hello, my name is #{firstName} #{lastName}" + (spouse ? " and this is my spouse, #{spouse.firstName} #{spouse.lastName}" : "")
end
end
Thanks, Glenn. Again, I'm struck by how Ruby's strength lies not in the core language itself, but the various "macros" that they've defined (such as attr_reader and attr_accessor or attr_writer). This notion of "core language with user-defined extensions" is a powerful one, and I hope to show how Scala does much the same in its language definition.
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 Wednesday, March 01, 2006
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Victoria .NET User Group topic
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As Joel before me, I'm going to be in beautiful Victoria, British Columbia, on April 4th to present at the Victoria .NET Developers Association, and as usual, the topic of what to present has come up.
Normally, this is a subject that the user group lead and I sort of hash out in private beforehand, but in this case, Nolan Zak (the user group lead) suggested I post here and call for suggestions. So, here's a list of topics I can present on, send me your thoughts.
- Pragmatic XML Services: you know about SOA, you've heard the Four Tenets.... now what?
- Intro to WCF: All you need to know about Microsoft's latest communication stack.
- Web Services: Overview of the specs, the stacks, and the standards. What's critical, what's useful, what's vendor hype and fluff.
- C# 3/LINQ: What's in their heads for C# v.Next
- (Or suggest your own idea.)
(I won't promise to take the most heavily-voted suggestion, but it'll weigh in pretty heavily. So no racketeering with the other members to rope me into speaking on FoxPro or something. )
.NET
Wednesday, March 01, 2006 7:05:35 PM (Pacific Standard Time, UTC-08:00)
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 Thursday, February 23, 2006
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A personal moment
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I know that many readers of this blog complain when I take time out from technical topics to talk about personal stuff, so if you're one of those folks, move along. This is about as personal as it gets, and fair warning: if you're going to complain about this post, I'm going to ignore you, at best.
Daniel Steinberg, a fellow No Fluff Just Stuff speaker, lost his seven-year-old daughter not too long ago, and he wrote the story up in a really poignant and moving piece he called "Dear Elena".
Dan, you can't imagine how terrible I feel for you right now--that's every parent's worst nightmare. I wish there were something I could do or say to make this time easier or less tragic for you, but of course there isn't. She sounds like she was a wonderful little girl, and I'm saddened by the fact that I didn't get the chance to meet her. My thoughts and prayers are with you and your family right now.
Now, if you'll all excuse me, I'm going to Skype my six-year-old son at home. For what I would hope to be a fairly obvious reason, I feel the need to give him a hug from here in London.
Thursday, February 23, 2006 2:49:37 PM (Pacific Standard Time, UTC-08:00)
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 Wednesday, February 15, 2006
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It's dogma that's bad... not Spring
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Several people have commented on my recent posting about Spring, and I want to make something clear: I'm not saying that Spring (or Hibernate, or EJB, or anything else) is a bad technology. I'm saying that walking up to every project, assuming that Spring will be THE answer, is bad. This kind of dogmatic approach--which, by the way, more than anything else is what led to the downfall of EJB as a popular technology--is bound to bite you in an uncomfortable place sooner or later.
One commenter, in particular, chastised me for not providing specific examples regarding where Spring may fail; I'm not going to stand here and make an exhaustive analysis of Spring's strengths and weaknesses. Besides being something that's already being done elsewhere, it would be beside the point that I'm trying to make--that dogma of any form is bad.
Look, so you've been successful with Spring on a few projects--that's good, and I encourage you to consider Spring again for your next couple. But don't make the dangerous assumption that using Spring will always yield success. In fact, let's take this out of the realm of Spring entirely and restate the point: "Look, so you've been successful with [[TECHNOLOGY-X]] on a few projects--that's good, and I encourage you to consider [[TECHNOLOGY-X]] again for your next couple. But don't make the dangerous assumption that using [[TECHNOLOGY-X]] will always yield success." (Where [[TECHNOLOGY-X]] can be, but isn't limited to, one of Spring, Hibernate, EJB, J2EE, COM+, WCF, CORBA, XML services, relational databases, stored procedures, managed-code-inside-the-database, highly denormalized relational data, highly normalized relational data, ....)
Java/J2EE
Wednesday, February 15, 2006 1:39:59 AM (Pacific Standard Time, UTC-08:00)
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 Tuesday, February 14, 2006
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Want Ruby-esque features on the JVM (or CLR)? Introducing Scala
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Recently, while cruising the Internet (and, in particular, the Lambda-the-Ultimate site), I ran across the Scala programming language, latest brainchild of Martin Odersky (of GJ fame, which of course was derived from Pizza, among others). It's another entry in the hybrid functional/object language space, and as such, has a lot of interesting features that Ruby holds, but runs on the JVM (and can actually cross-compile into a .NET assembly, though it does require some slightly different mappings), and as such means developers don't have to make a wholesale commitment to the Ruby interpreter.
I thought I'd share some of the more interesting bits of Scala in this and a few more blog posts.
The high-level stuff
First of all, from the Scala website, let's get the high-level overview stuff out of the way:
- Scala is object-oriented. Scala is a pure object-oriented language in the sense that every value is an object. Types and behavior of objects are described by classes and traits. Class abstractions are extended by subclassing and a flexible mixin-based composition mechanism as a clean replacement for multiple inheritance.
- Scala is functional. Scala is also a functional language in the sense that every function is a value. Scala provides a lightweight syntax for defining
anonymous functions, it supports higher-order functions, it allows functions to be nested, and supports currying. Scala's case classes and its built-in support for pattern matching model algebraic types used in many functional programming languages. Furthermore, Scala's notion of pattern matching naturally extends to the
processing of XML data with the help of regular expression patterns. In this context, sequence comprehensions are useful for formulating queries. These features make Scala ideal for developing applications like web services.
- Scala is statically typed. Scala is equipped with an expressive type system that enforces statically that abstractions are used in a safe and coherent manner. In particular, the type system supports generic classes, variance annotations, upper and lower type bounds, inner classes and abstract types as object members, compound types, explicitly typed self references, views and polymorphic methods. A local type inference mechanism takes care that the user is not required to annotate the program with redundant type information. In combination, these features provide a powerful basis for the safe reuse of programming abstractions and for the type-safe extension of software.
- Scala is extensible. The design of Scala acknowledges the fact that in practice, the development of domain-specific applications often requires domain-specific language extensions. Scala provides a unique combination of language mechanisms that make it easy to smoothly add new language constructs in form of libraries: any method may be used as an infix or postfix operator, and closures are constructed automatically depending on the expected type (target typing). A joint use of both features facilitiates the definition of new statements without extending the syntax and without using macro-like meta-programming facilities.
I'll be the first to admit, a lot of these features are new to me, but the set as a whole is impressive, even more so because they all seem to derive from some core features inherent to functional languages, and the overall impression I get is that despite the language feature set, it doesn't feel "cluttered" or "clumsy", which is a feeling I got from Groovy in some places.
Enough overview. Let's look at code.
Hello, Scala
OK, Scala really isn't all that interesting as a Hello World program, but it does highlight one of the more interesting elements of Scala that I already like:
object Hello {
def main(args: Array[String]): Unit = {
Console.println("Hello, Scala!");
}
}
First, we see the "object" keyword where "class" would be expected in Java; this means that this is a singleton object, and Scala will handle the construction of the singleton instance as well as the prevention of any further constructions. Singletons have become so prevalent in Java (and other OO languages) that it just makes a lot of sense to make it a first-class language entity. There's some other interesting elements in that sample that differ from the traditional Hello Java program, but we'll leave that alone for now. Put this code into App.scala (once again, another language has corrected Java's requirement that filename-match-classname, which I've always found odious and annoying), compile it with scalac, and you get a slew of .class files out the other end. Run the program with the "scala launcher" (which is a simple batch file around the Java launcher, to ensure the Scala support libraries are on the classpath) with scala Hello, and you get the expected result.
Some of what's interesting to see here is that the Scala compiler actually produced two .class files--one entitled App.class, another called App$.class, the second App$ class apparently to provide "module" behavior (which I suspect is related to the singleton-ness of the object declaration in the code). As you might expect, Scala injects some additional support methods into both classes, including getScalaType, which is obviously intended to return the type of the object to Scala, just as the .class or getClass does for Java. Which brings up another interesting point.
Scala presents a unified type hierarchy, such that scala.Any is the root of the type system, and (like the CLR) is bifurcated into two basic elements, one being the object-family of types (java.lang.Object, known to Scala as scala.AnyRef) and the "primitive type" family of types, known to Scala as scala.AnyVal. Scala calls these reference classes and value classes, respectively--the same monikers the CLR uses. There's also reference to a type scala.All, which the introduction/tutorial page puts at the bottom of the type hierarchy, apparently inheriting from everything, but I'm can't find documentation on it or what purpose it serves. *shrug* More on that later, I guess.
Another interesting tidbit is that we can run Scala interpretively, the same way we can do to Groovy:
> scalaint -nologo HelloWorld.scala
> HelloWorld.main(null)
Hello, world!
(): scala.Unit
>:q
Which implies, then (though I haven't done it yet), that the Scala language could be used as a DSL to analysts and/or domain experts within an existing Java application.
Update: Forgot to mention, Scala has another interesting element to it that makes it very interesting to Ruby in much the same way:
object HelloWorld2 with Application {
Console.println("Hello, world!");
}
The with Application clause makes the entire content of the class basically a single script, as if the def main method has been declared to be the entire body of the class. This makes Scala very interesting as a potential scripting language, since now no explicit entry point need be defined; you can assume it's already present and accounted for, yet still relies on the underlying rules of the JVM (that the entry point must be defined as a static method, blah blah blah). Describing how with Application works is a bit difficult to describe without going into larger detail on other topics, so I'll leave that for a future discussion or (as book authors are so fond of writing) as an exercise to the reader to figure out.
I consider myself a relative newbie to Scala, but as I progress through the language and see some useful applications of features, I will blog more. I'll also blog some of the features themselves, but you can find that for yourself by working through the Scala tutorial material on the site, if you're so inclined. In the meantime, catch the presentation I'm doing on Scala at the No Fluff Just Stuff symposiums, starting 2Q this year.
And, by the way, for those of you in the .NET space, Scala does, as I mentioned before, cross-compile to .NET assemblies, though I haven't spent much time exploring this. Frankly, I'd be more comfortable using Scala in the .NET world if there was a .NET-based compiler for it, rather than having to install a JRE just to run the compiler, but F# serves much the same space in the .NET world that Scala does here, and that's another language I'm pursuing with some vigor, as well. More on that later. 
Java/J2EE | .NET | Ruby
Tuesday, February 14, 2006 12:50:17 PM (Pacific Standard Time, UTC-08:00)
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 Monday, February 13, 2006
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My interview with Joshua Bloch and Neal Gafter from JavaPolis 2005 is now live
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There are a few things, I've found, that are fun about being a speaker and general rabble-rouser, but none of them are nearly as much fun as when I get an opportunity to interview industry icons and ask them all my questions on camera. In this case, while at JavaPolis2005, my victims were the well-known pair Joshua Bloch and Neal Gafter, who, more than anyone else in the world, are most directly responsible for the language features that came in Java5. I tried to keep the interview pleasant and friendly, but I did ask the questions that've bothered me for a while, like "Why did generics end up the way they did?", "Is Java too complicated and hard to use now?" and "What are you doing at Google these days, anyway?"
Online (registration required) at the JavaPolis2005 site. Keep an eye on the site for the other interviews Dion did, as well as one more I did with Brian Goetz, who's got a GREAT book on Java Concurrency coming out in 2006.
Java/J2EE
Monday, February 13, 2006 5:05:26 PM (Pacific Standard Time, UTC-08:00)
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 Wednesday, February 01, 2006
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From the "Yeah, what he said" Department
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CrazyBob just wrote about how he "doesn't get Spring", and although it runs the risk of sounding like something from the "Me, too" bandwagon, I have to say, I agree with him (and have been saying this in conferences and panels for a while now):
Even worse, I've noticed what I consider to be a dangerous and blind increase in the rate of Spring adoption. I've yet to read a critical article or book on Spring. It seems like everyone loves Spring except me.
More importantly, I think Bob nails it with this:
Maybe Spring adoption is a knee-jerk reaction to J2EE. "J2EE is bad, and the Spring guys say their stuff is better, so Spring must be good." It doesn't work that way.
For starters, I'm with Bob on the statement that blind adoption of Spring is dangerous. I wrote once before that dogma of any form is bad, and Spring dogma is just as bad and just as dangerous as J2EE dogma ever was, for much the same reason: dogma discourages thinking. Walking onto a project, prepared already to believe that Spring is the best solution to the problem, without considering the context, is just as bad as when we did that with J2EE. In fact, any technology can fall into that trap, be it Ruby, .NET, J2EE, Spring, LAMP, Vista, COM/DCOM/COM+, you name it. ANY kind of dogma that allows developers to shut off the analytical part of their brain is dangerous. Spring is a useful technology, no question. But so is J2EE, and so is .NET, and so is LAMP, and...
Don't ever make the mistake of letting dogma drive your technology decisions, period. No matter who justifies them. I thinke states it best when he says
If you do [adopt Spring], go in with your eyes wide open. Be skeptical, critical. Just because someone has a popular Open Source framework, they have slick marketing, and they're supported by a big vendor (IBM pushed Struts on me for a number of years after all), it doesn't necessarily mean they know what's best for you or even that they know better than you. Dogma, of any form, is not to be trusted.
Bob then goes into how he likes the setter-injection that Spring provides; I personally don't have the same degree of fondness for dependency injection, to be honest: I find JNDI (and Service Locator) to be a superior approach, mostly because with the Service Locator, I can control when the resource moniker is resolved, meaning that if the resource should fail somewhere during the call, I can control where and how I go back to the Service Locator for a failover attempt. More importantly, I can re-resolve the resource as my failover policies permit, and I'm not held hostage to how--or mre importantly when--the container decides to inject the dependency.
At the end of the day, it's important to remember that "lightweight" and "testable" doesn't have to mean "Spring". In-process testing of EJB components is possible thanks to the in-proc nature of the OpenEJB stack. Testability of JNDI is easily accomplished with unit tests that use the Hashtable JNDI provider that Sun makes available in the Java Tutorial, if you want or need to test the Service Locator code itself. Or, you take the "black box" approach (as some recommend for servlet containers), and test your code through the container itself by doing the heavierweight communication through the communication stack from out-of-process calls. In the end, it's not the APIs that define the tool's testability, but the ability to embed the tool inside a unit-test environment.
Would I recommend Spring? Certainly, under the same circumstances and for the same reasons I'd recommend J2EE: when it's appropriate, because there's some good stuff there, and it's well-known and an official (in J2EE's case) or de-facto (in Spring's case) standard.
Oh, and let's not forget, this applies to any technology, including the upcoming rise of dynamic languages...
Java/J2EE
Wednesday, February 01, 2006 1:08:13 AM (Pacific Standard Time, UTC-08:00)
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 Friday, January 13, 2006
 Wednesday, January 11, 2006
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LINQ paper comments and feedback
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A number of you have made comments about my LINQ paper, and rather than respond in comments in turn, I thought I'd gather them up and respond to them en masse. So, without ado....
Stu Smith said:
Nice article. Two things occur to me immediately...
- Based on my current understanding of LINQ, it's purely for querying, and so compared to most O/R systems it lacks caching support. (ie its queries may be optimal but that's not much consolation if it keeps re-executing them).
- The O/R system we use (which admittedly only needs to support a particular kind of application) solves the 'lazy load vs N+1' issue by generating joined queries based on either the path taken to the data, or on particular routes to a marked-up tables. ie, if you navigate from a Customer to a collection of Orders, that's a single select. If you then start iterating the Orders and inner-iterating the OrderDetails, then on the first one a second joined select is issued, and for subsequent iterations the data is already cached and thus no further SQL statements are emitted.
Thanks, Stu. Responses:
- No, LINQ can, in fact, do any sort of relational manipulation, including INSERTs, UPDATEs and DELETEs, but the real strength of the language integration is in the query aspects, particularly the fact that LINQ can do these queries across any rectangular data store, so it's fair to say that LINQ is mostly about query.
- I'd be interested to hear more about your solution to solve the lazy-load issues, partcularly how you handle the situation where you need to display only a small part of the full OrderDetails data--remember, part of the criticism of O/R is that they either eager-load too much, or lazy-load too much, and can't infer the amount or areas of data to retrieve that's "just right".
Bryant wrote:
I thought the article was well written and informative. While I think it's cool that I might one day be able to use the same object model to query databases, XML documents, and even the file system I still feel compelled to look back upon my days as a DBA. This looks a lot like building ad hoc SQL statements in the code except we're a little more type safe here. LINQ still does not answer the question of storage abstraction. The developer still needs an intimate knowledge of the database structure. So, LINQ appears to cover "Conflicting type systems" and maybe "Transactional boundaries" and "Query/access capabilities". There are still four more items in your list that I don't see being solved with LINQ. Your article was a great read but sorry, I am still not excited.
We are building ad-hoc statements in the code, although this depends slightly on your definition of "ad-hoc statements" (my early experiences lead me to a definition that says "ad-hoc statements" means "users can throw SQL at the database", whereas "developers throwing SQL at the database" isn't ad-hoc, as the SQL itself is known prior to execution; I can see where others' definitions may vary on this, however). I do have to point out, however, that LINQ *does*, in fact, answer the question of storage abstraction, though perhaps not to the degree you prefer. I see LINQ's ability to hide the difference between in-memory storage and external-database storage as storage abstraction, but what it does not do (rightly, in my opinion) is try to hide the differences between rectangular (relational), hierarchical (XML) and referential (objects) storage. That is the area where the impedance mismatches kick in, and that's what's the hard part to solve. As to the last four items, well, one could always say they're not done yet... Seriously, I think it's a great start, and my excitement comes not necesarily from what LINQ can do right now, but from the idea that it opens up and explores an entirely new avenue of research that nobody else seemed to be interested in exploring.
James commented:
I thought the article was great! I'm a little unclear as to why it's not getting ranked better on MSDN but for someone who didn't really understand/appreciate the problem domain LINQ is serving, your article really got me thinking and cleared up a lot of fogginess in my mind. Excellent work!
Thanks for the praise, James, and as for MSDN's ranking schemes, a couple of other MSDN authors have suggested that there's some "article assassination" going around the site, so maybe that's it. I'm glad you find it intriguing and that it "got you thinking"--that, in many ways, was the point in the first place.
Andy Maule said:
Very interesting! I liked the discussion of Rail's ActiveRecord which I think is an approach that most people miss when talking about OR Mappings.
There's a good research paper discussing the same stuff here. It mentions something recently developed for doing statically typed queries in Java 'Native Queries' which is an interesting comparison to LINQ. Anyone interested in this area should take a look.
I'm currently doing a PhD in this area, and I have to say that LINQ is making things very interesting.
Well, good luck on your PhD, and thanks for the link--I'm definitely interested in following up on anybody who's pursuing this in the Java space. Along those same lines, Marius Gherorghe pointed out that
Karmencita is my lightweight alternative for in memory object querying.
and again, I appreciate the link.
As for the rest of you who offered kudos (Bart De Boeck, Dan Kahler, Paul Wilson, Eric Bachtal), thanks; every author likes to know that their work is appreciated, particularly when so much of what they say seems to stir up more controversy than discussion. 
.NET | Java/J2EE
Wednesday, January 11, 2006 7:52:13 AM (Pacific Standard Time, UTC-08:00)
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 Friday, January 06, 2006
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Am I a curmudgeon of technology? You betcha
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Matt Morton commented, "One might be able to say that Ted Neward is cynical about any new technology. You might also say he puts himself in the position of the "old" kermudgeon (sp) who opposes anything new and cool." Yep, guilty as charged, for a very specific reason.
Ages ago, when EJB first shipped, I was one of the first who looked at it with stars in my eyes. It seemed like such a great, easy solution to all the problems of developers building server-side systems (and I'd done a C++-based 2-tier, CORBA-based 2-tier and Java/NetDynamics-based 3-tier system before this, so I kinda fit into that space already). I was excited. I was ready to swear it to all my friends. And then....
It was a lunch with Don Box and Kevin Jones, shortly after I'd joined DevelopMentor, and I asked Don and Kev about EJB. Don looked at Kev with this silly grin on his face, and Kev just shook his head and said, "It's a thing on a thing. That's always slower than just a thing." Slowly, the light dawned. Over the course of several conversations with Kev and Don later, I came to realize that EJB wasn't a distributed object technology, but a component technology focused on transactions. Over time, developers' stupidity in using EJB for their single-database simple-HTML-form apps drove me to be widely proclaimed as an "EJB expert who consults against EJB", which isn't exactly correct--I've recommended EJB in scenarios, but only where it seems appropriate.
Which, if you think about it, is what we're supposed to do: recommend tools where they're appropriate.
What does this have to do with being a curmudgeon? Simple: I trust no technology until it proves itself to me. Our industry is SO filled with hype, it's surprisingly easy to get caught up in the energy and excitement that surrounds a new tool, particularly those that deal with presentation issues. (Face it, folks, the "jazz factor" surrounding Avalon/WPF or Ajax is exponentially higher than that surrounding RIFE/Continuations, despite the fact that the latter is far more interesting from a technology perspective. Why is this? Because you can SEE the niftiness in Ajax; the continuations story isn't something you can show off to your mom or impress your significant other.) I look at new tools, new technologies and deliberately look to find the flaws, the various fallacies they fall prey to, and I routinely caution people against them JUST because they're new. I would much rather err on the side of caution and hestiation than fall into the trap of hyperbole and bandwagon, because I think, ultimately, it's a more responsible position to my clients and audience.
I don't think I'm unjustified in this position: there's an unhealthy absence of cynicism in our world right now. My two big examples: the terrible tragedy of the miners in West Virginia (why didn't anybody in the media CONFIRM the story of their rescue before reporting it?) and the South Korean human cloning story. Or the supposed report of "cold fusion" from a decade or two ago. Our industry could use, I think, from a large dose of, "OK, so you've created a new framework. What's it to me?" right now.
Matt went on to say,
I dont totally agree with #4 though. When a large scale Ruby project fails it wont be because of the language. Just as it is faulty to claim a language will reduce project failures, it is just as faulty to claim that a language or platform will be the cause. Projects fail because of people, plain and simple. People in general have trouble being honest especially when they have something vested emotionally (or financially) in a project. Perhaps this is what he is getting at. The proponents are so emotionally involved with Ruby that when less experienced folks try to apply it to a larger scale the project, it will blow up.
Personally I have found that Rails and Ruby are a joy to use. I guess then you could say that I get emotionally involved with things that bring me joy. Perhaps Rails strength is its weakness. It is such a joy that it blinds you to its true uses.
Let me clarify my point: Ruby and Ruby-on-Rails are like those specialized tools that my grandfather (a well-known, well-respected plastics industry founding father down in Southern California) used to use when he was doing his diemaking in his shop in Oregon--they're tools that ONLY a master craftsman can truly appreciate and use well. Put them into the hands of a novice... like me... and I'm more likely to cut off an appendage than I am to create great beauty or a workable mold for stamping out intricate plastic parts. I suspect you, and many of the others using Rails, know that. But, and here's the rub, that message isn't being heard, and it's a matter of time before a team of novices tries to use Ruby and Rails to do a project, yielding in the end nothing more than human body parts on the floor. THAT will be the well-trumpeted Rails failure, and the backlash will begin.
Which, if you think about it, is exactly the same thing that happened with EJB before it.
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WHY wasn't this out for Christmas this year?
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Lego, those folks who brought you Mindstorms in the first place, have done it again--they've announced a next-generation programmable brick, the NXT, that offers some really cool enhancements, including Bluetooth capability. Suddenly, the old Robotwar clones from ages ago take on an entirely new meaning....
More interestingly, supposedly they've announced that the VM itself will be documented, which leads me to wonder how long before we see J-NXT and NXT#. It's amazing how the managed environment is just spreading like wildfire through the world, if'n you ask me....
Hey, Santa, if you're listening, this just went on my list in a BIG way. 
Friday, January 06, 2006 4:36:54 PM (Pacific Standard Time, UTC-08:00)
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 Thursday, January 05, 2006
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Struggles with Vista 5270 and VMWare 5.5
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So the December CTP of $g{Vista} is available, and I'm finding a recurring problem trying to install it into VMWare. When I tried this with the Beta1 of Vista into VMWare 5.0, the same problem occurs as what I'm getting now: when trying to boot off of the .ISO inside of VMWare (in other words, not physically off a burned CD/DVD, but out of the .ISO image itself mapped into the virtual CD in VMWare), I get a BSOD every... single... time. Is this indicative of a f-ed up installation of my VMWare image, is this a known bug in Vista (sidenote: yes, I know about the raw partition issues with Vista, but doing an XP-first install of Vista gives the same BSOD on reboot), or is it just the combination of ISO-image-and-VMWare? Anybody got ideas for a workaround or a fix?
Thursday, January 05, 2006 10:18:15 PM (Pacific Standard Time, UTC-08:00)
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Off-topic: Acquaintance seeking a J2EE expert with familiarity in other languages/environments
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I've been contacted by a third party (not a recruiting agency) who's having a hard time finding a J2EE architect with familiarity/expertise with concepts of architecture and the low-level chops not to lose sight of the code. To put it in their words:
This is strongly influenced by component-based methodologies such as OpenDoc, but would be extending the RCP Platform developed by Eclipse, and encompassing other concepts from systems such as Squeak... We are having trouble finding someone senior enough to understand the conceptual architectural issues, but technical enough to know important lower-level details such as how design choices will effect performance and scalability. I'd take the job myself, but they have a very specific dealbreaker requirement: you must live in the Northern California area. If you're one of those guys who knows the list of technologies in the J2EE platform, has used all of them at least once or twice, and still reads the Lamba-the-Ultimate blog, drop me a note and I'll put you in touch.
By the way, DON'T send me your resumes--in your email to me, tell me what your favorite alternative language or platform is, and why. I'll use that to know if you're somewhere in the ballpark. 
And no, job postings are NOT going to become a regular part of this blog; I'm doing this as a once-off. (My motivation? I just want to help these guys; this isn't an easy requirement to fill, and I'm hoping I get to meet whomever it is they end up selecting, 'cuz I'm thinking they'll be a kindred spirit. )
Update: They sent me a formal job description, and it seems the desires changed just a bit. *shrug* See for yourself:
A lead software architect for [[name snipped]]. Applicant must be able to take a high level conceptual framework and architect a conceptually sound implementation using open standards in collaboration with an existing team. Experience with Java, Eclipse, and the Rich Client Platform (RCP) sub-project in Eclipse is a significant advantage. Experience with Aspect Oriented Programming is a plus. Participation in the open standards community a plus (e.g. W3C and Eclipse standards communities). Five or more years of experience required with experience as a lead software architect, industry experience preferred. Opening is for a full-time onsite position.
Doesn't sound like they want too much, ya?
Java/J2EE
Thursday, January 05, 2006 4:49:25 PM (Pacific Standard Time, UTC-08:00)
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