Electric Politician

Banks and cards from different country with the same PayPal email

2011-02-11T20:17:00.000Z

...well sort of.

PayPal doesn't have the concept of people that live or travel to different countries. If you try and setup banks or credit cards in two different countries you will find it impossible. For starters, the address fields are limited to your initial country and there is no way around it.

Call PayPal and they say that you cannot have bank accounts or credit cards from different countries on the same account - why - you just can't so don't ask. They suggest creating a new email with an extra number on the end for each country. WHAT! I'm not sure about you, but I already have far too many username/passwords to remember as it is.

For a long time I just accepted this situations and only had a single account and just paid for everything with normal channels in other countries. However, that recently changed when I wanted to buy something from UK ebay and the only channel was PayPal. I tried once more to add my UK credit card to my Canadian PayPal account. The billing address was a mess and clearly wasn't going to clear if I tried it.

It was at this point I started looking into creating a new email address for the UK to sign up for a second PayPal account. And that's when it hit me. I use gmail as my main email and gmail allows you to put periods anywhere in your name without it making a difference. That is. johndoe and john.doe are the same in googles eyes. In fact j.o.h.n.d.o.e is the same as johndoe. But to PayPal they are very different. Bingo!

I simply put a full stop between my first and last names of my email and I have a second PayPal account with the same email address in a different country.

All my PayPal notifications from both accounts go to the same gmail address. I don't have to find a new email address, remember a new password (yes I use the same password for both PayPal accounts - but it is insanely long and complex.) I can buy using PayPal in each country. I suppose I could also transfer between each account, although I've not actually tried that and it probably isn't a service I really need.

I really don't like PayPal, I think their model is very broken and I doubt it will ever chip away at Visa or Master Card until it changes. Now I have a UK PayPal account I still couldn't use my UK credit card because I had to wait 2-3 days to verify my account. Surely Visa and Master Card have done that already, they have 3D secure for online transactions, why does PayPal always seem to block your use of their service?

I hope this workaround can help you in time of need - just don't expect it to work without delay.

Get started with Rails with all the Railscast movies offline

2011-01-28T14:53:00.000Z

Getting offline content from Railscasts.com is very handy.

This script is a slight adjustment from http://niczsoft.com/2010/01/download-all-railscasts/

This version gets the railscast movies starting with first, or oldest, movie rather than starting at the lastest first.

wget -q -O - http://feeds.feedburner.com/railscasts |\
awk -F \" '/media:content/ {print $4}' | \
perl -e 'print reverse <>' | \
wget -i - -c

I urge you to read this from Railscasts.com and give back in someway.

The lazy pattern

2011-01-25T23:31:00.000Z

"A little bit won't hurt. A little bit doesn't matter." I hear this more than I want and so I'm having to write this little rant to cool me off.

Writing code that works is relatively easy. Writing code that is too complicated is easy too. The balance between easy and over complicated is hard to find. Writing good, SOLID, object-oriented code is the goal.

Every shortcut you do shows to others in your team that it is okay to use shortcuts as well. When a developer is asked to extend a class or add a feature they often just copy what they see around them. And if that is a bunch of little shortcuts it can rapidly become a big problem.

I rarely see Developers want to improve the camp ground. (Uncle Bob asks us to follow the boy scout rule and leave the camp ground just a little cleaner than it was before.) It's hard work, but I love this rule. I follow it happily.

Take the sink in a student house; if someone leaves a dirty bowl in the sink, the next person comes a long and thinks it's okay to stack their dirty bowl next to the one already there. Before long there are lots and lots of dirty dishes in the sink and it's a big job to clean it all up.

Taking the dirty dishes analogy a little further.

If you are the sort of person that wants to wash their dirty dishes but finds that the sink has dirty items blocking your way, all of a sudden it's a bigger job than you first thought - do you clean all the dishes or do you copy what the other guy did?

This decision point is where that devil laziness really comes into play. Do you do a little bit of lazy code, next to the other little bit of lazy code, after all it isn't really that big a deal.

And so it goes on, a little bit here, a little bit there, and before long everyone is copying the lazy pattern.

I find String to be one of those little lazy decisions that is easy to make, easy to follow and very easy to stack up and get out of control.

For example, the use of String for what really should be a value object, an object that has no conceptual identity. I would extend this to many Strings like a person's name, a telephone number or a postal code - even if these objects do nothing more than wrap String.

Some would, I'm sure, argue this is over engineering. But if I've got a constructor that takes three parameters, all of them Strings, creating value objects gives you at least some type safety, and an object that can be extended with more behaviour down the line. Some would say that's just good OO, without it, it's just a bunch of Strings.

I'm not innocent here - I've cut the corners in the past. But what I have learnt over the last couple of years is to always put that extra effort in, create something that is built around good objects and follow the boy scout rule. It really does pay off and the alternative always bites you in the end.

Google URL Shortening get API

2011-01-11T07:57:00.000Z

The long arm of google has found its way into the url shortening space. http://googlecode.blogspot.com/2011/01/google-url-shortener-gets-api.html

It seems there is no area that google won't go to track, trace and analyse your data. Don't get me wrong, I love many google apps, all of which I use free of charge. That is, I don't actually pay them direct. What they do with my time in the application makes them money; and good luck to them.

I did find it particularly funny to see goo.gl url shortening is the fastest available. http://royal.pingdom.com/2010/10/29/is-goo-gl-really-the-fastest-url-shortener-chart/

I mean...how fast does url shortening have to be!

Find the fun, forget the money

2011-01-10T14:00:00.001Z

One of my goals this year is to actually put some of those ideas I have rattling around my brain into code, and even better into other peoples hands to use.

I did put one caveat to this goal: It would be for fun, not money.

I love start ups - if that is what I should call it - the energy is in tune with my frequency. I'm going to be working on a couple of projects, with a couple of like minded friends, and I am already enjoying the collaboration over technology.

The will be no hocket stick projection of revenue, no early retirement plans in the south of France, no VC pitch. Going through the whole process is what I feel is important. Taking an idea; then create that idea; and finally letting it out early into the wild for peer review.

Making money from the web is notoriously hard. I recently read this blog post which I tend to agree with: Sorry, your “cool” webapp is probably not going to make money That said, this shouldn't put you off, as the post suggests there is money to be made, but don't focus on money.

Focusing on money never actually helps innovation or motivation. RSA Animate - Drive: The surprising truth about what motivates us

So practice, practice, practice is mantra for 2011. Delivery something useful, again and again. Each time there will be failures and falls that will have to be overcome, and each of those lessons will hold true value.

And you never know, perhaps one of these days we might create something that people love to use - and that's got to be worth more than money, right?

Checked vs Unchecked: That old chestnut!

2010-02-03T21:30:00.047Z

I really thought this one had gone to bed, but recently a debate on checked vs unchecked exceptions arrived at my door.

I'm associated with this Butler IO, it's basically a helper for getting and writing resources.

Does things like this:

String fromClasspath  = ButlerIO.textFrom( "res:articles/steve_jobs.txt" );

The workings of textFrom basically come from this method.

public static byte [] bytesFrom(InputStream inputStream) {
    ByteArrayOutputStream out = new ByteArrayOutputStream(BUFFER_SIZE);
    try {
        copy(inputStream, out);
 return out.toByteArray();
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

The project wasn't up a day and a complaint was received about catching the checked and re-throw a runtime exception. In their words; "... throwing an unchecked exception here is just pampering the user in false safety. Checked exceptions are there for a good reason"

This project was built to help make clean code and has followed Bruce Eckel's thoughts on this subject of exceptions.

I can't think of a time when you can recover from an IOException, and this way can identify programmer errors early and clearly at runtime. The utility doesn't enforce you to catch any exception, which makes for cleaner code...right?

Isn't the point that any error handling be the choice of the caller; Butler can't do anything about a missing file, and doesn't presume to know what the caller wants to do either.

Have I got this wrong? I don't think so! But I would appreciate some feedback from you guys. Thanks.

Do you have conference envy?

2010-02-02T12:53:00.000Z

Conferences are big business. It's the hotels, it's the conference centres and its the major players sponsoring the event. In the technology sector — and software — you can go to QCon, ApacheCon, JAOO, and those are just the big ones.

These yearly conferences are filled with some of the best — and dare I say iconic — players in the business. The people that the write books you study, the blogs you read, the practices you follow. These gatherings give you the ability to see, hear and possibly interact with these incredible minds....but only if you are rich!

At £2000 a piece — and that's just to go and not including hotel and travel — it's not an amount easy to swallow or cough up. Perhaps if the company you work for has money or is willing to part with money on your behalf, you might be able to attend one of these grand events. If you work for a start up or are self-employed or a company that doesn't value its employees attending gala events, you're bang out of luck.

You'll just have to wait and hope for the video to pop on InfoQ.

The video of the presentation will often suffice, all stuff no fluff. But what I object to is this notion that these conferences are a "must do". Is this conference envy? Potential employers ask about potential employeses in interview and damn it I even ask people interviews if they have attended them. Some even dare to bill themselves as "By Developers for developers." What a pill of poop!

Conferences aren't always a lost cause. There are good value events which enable passionate developers to mingle the the like minded and hear from their idols. XP Days has always been reasonably priced and there was even a free Scale Camp in London late last year that boasted some impressive speakers.

But just remember: 2000 quid can buy you a lot of books.

Top 10 reasons not to do a top 10

2010-01-29T15:16:00.002Z

Seeing them pop up in your rss feed can make you bitter.
They wouldn't even look good on an over-sized comedy iTouch.
You might be tempted to waste time commenting, "Gee, thanks, this was awesome!"
They will suck your will to live right out of you.
Your list is already out of date.
They always contain useless arbitrary statistics.
It's a cheap way to get traffic to your tumbleweed blog (guilty as charged.)
They made me waste time thinking about this damn list.
You are still reading this, although this list sucks the most.

... ... ... ...

Well....you can think of the number one reason why you shouldn't make a top 10.

Add Custom Font Using FOP

2010-01-29T12:04:00.021Z

This post is about Java PDF generation using Apache FOP and XSL-FO. Your client wants a font in their PDF report generation that isn't available in the system. I found the documentation a little over the top and obscured what I needed to do. Therefore in 3 easy steps this is what you need to do:

Create a metrics xml of the font using FOP Utility.
Define custom font in FOP configuration.
Use font in XSLT.

Create a metrics xml of the font using FOP Utility I'm using maven and therefore it is easier to create a simple class within my project to call FOPs font util rather than messing about with command line java and classpaths.

import org.apache.fop.fonts.apps.TTFReader;

public class ConvertFont {
public static void main(String[] args) {
    TTFReader.main(new String[] {"/home/farrd/fonts/TheSans","/home/farrd/fonts/TheSans.xml"});
}
}

Define custom font in FOP configuration Copy the font and the metric xml file into your project so that it is available on the classpath. Now create a fop configuration file and define the font. Apache FOP uses Apache FVS so you can prefix the location of the font files with res and it will resolve them correctly. (nice!)

Use font in XSLT When constructing your FopFactory, set the above configuration. I'm using BulterIO to resolve the file. (this is a nice also [yes, shameless self plug as I've worked on some of the code in BulterIO])

...
FopFactory fopFactory = FopFactory.newInstance();
try {
    fopFactory.setUserConfig(ButlerIO.fileAt("fop_config.xml"));
} catch (Exception e) {
    throw new RuntimeException(e);
}

fopFactory.setURIResolver(new URIResolver() {
    public Source resolve(String href, String base) throws TransformerException {
        return new StreamSource(ButlerIO.inputStreamFrom(href));
    }
});
...

You can now reference your font in the normal way within your XSLT.

...


...


...

MapReduce In Groovy

2010-01-14T15:17:00.002Z

I came across an old post on Joel on Software about MapReduce and functions as first class citizens. You can read it here. I thought I'd have a go at doing the examples in Groovy. I know these examples have been abstraction already in 1.5+, but that takes the fun out of this exercise.

Closures to sum and join

def d = [1,2,3,4]
def c = ["a","b","c"]

def sum = {param ->
  def result = 0
  param.each{result += it}
  result
}

def join2 = {param ->
  def result = ""
  param.each{result += it}
  result
}

println sum(d) // 10
println join2(c) // abc

Abstract out the essence of sum and join into reduce

def d = [1,2,3,4]
def c = ["a","b","c"]

def reduce = { fn, a, init ->
  def result = init
  a.each { result = fn(result,it) }  
  result
}

def addition = {param1, param2 -> param1+param2}

println reduce (addition, d, 0)  // 10
println reduce (addition, c, "") // abc

This isn't going to take on Google, it was just a little exercise in functions as a first class citizens.

Which is the best web framework?

2009-09-23T13:03:00.000+01:00

This is always a lively debate after a few pints. It generally falls, with the Java heads I've had the pleasure of drinking with, to the best of the worst...cus they all suck in someway or another. But for me, after watching this short webcast, the debate is over. How to create an ajax enabled blog from scratch with atom feed in 15 minutes.

Manage JPA Tables Using An Active Collection

2009-09-06T12:43:00.000+01:00

No ceremony, no fanfare: the first open source software that I'm part of. http://github.com/opsb/active-collections/tree/master#

Science of Motivation

2009-09-01T15:07:00.000+01:00

I've worked for several companies where the idea of personal development time was put on the table. In all cases 'the business' disagreed with the idea with the usual fear of loss of productivity and therefore missed deadlines. This fear extends to agile software development, especially as software gets closer to a big release date; it's the developers that put in 80+ hour a weeks that are the ones that get the pat on the back from 'the business', rather than the developers that deliver high quality and robust software. Now I sound a little bitter here, and perhaps I am, but I come from a science background and I like to question beliefs and do things because of evidence not for historical reasons. A great many companies have a provincial attitude that is stranded in old fashion dogma, perhaps with videos like this time are a changin.

How to find information about characters

2009-08-14T12:37:00.000+01:00

Dealing with languages, characters, accents, squiggles, dots, dashes and all other type of wordy thingymebobs in software can be a real pain. ASCII, UTF, UNICODE, it's all a real mess (IMO.) But rest assured, this site will come to your rescue: fileformat.info Everything and anything on characters for the digital world are covered here, with a very handy search capability.

Tweet Tweet Tweet

2009-08-07T09:27:00.000+01:00

I've finally joined Twitter and so far so good. I've been disillusioned for some time with mainstream news and broadcasting networks and basically stopped reading and view them. Since then I've spent a great deal of time only reading technical blogs, but that is very dull and I needed something else. Twitter has so far giving me a broader aspect of the intraweb thingy and I've enjoyed it's simplicity and mostly it's breavity. Now, I suppose I can just go out and look up these things up for myself, and I'm not just about to stop doing that, but this way I can get information and opinions from people I feel like I can trust; even if those people get some of their information from the mainstream. :) I've also add Twitterfeed, which promises to post a Tiny url of the latest posts of any blog feed onto my twitter page. And in a shameless way the first feed I've added has be my own blog. Tweet Tweet Tweet...

Sorting International Names

2009-07-22T11:36:00.001+01:00

My current employer has data on companies from almost every country in the world; lots of lists of companies from the four corners of the planet. When listing these companies in a select box it would be nice to have them sorted alphabetically. The problem is the standard approach to sorting would be to use a comparator or comparable interface. This will return something like this.


A, B, C, E, d

because the string compareTo looks at the int char value and capital E is a smaller number than lower case d and therefore comes before in a sort. It gets even more complicated when you add names with accented characters from places like Sweden, like å. å int value is much higher than standard A-Z and a-z and therefore comes after both upper and lower case letters. Step up to the plate, java.text.Collator. This little class understands your pain. But more importantly it understands language. It can perform locale-sensitive string comparison. What that means is the sorted list would be


A, B, C, d, E
A, å, B, C, d, E

...if you want it to be. It has the ability to sort upper and lower case with the same strength amoung other cool features.

The problem with Java Generics is.... (Redux)

2009-06-30T13:47:00.000+01:00

...while pair programming... bill > Hey, we could use generics here. bob > Great, why don't you drive. bill > Sure. What we need is a T here. Replace that return with T. Add another T here, and there you go. We can now use this for all types of things. Compile...check. Great. Let's fire up jetty. bob > Hey, what does that mean? bill > Strange...it compiled ok. Oh! No problem. What we need is to add a ? here, then extends that to type T and that should work. bob > Nope!! bill > Right, if move that ? to here, then use super of not extends, add T here that will work. bob > Sorry, still not happy. bill > Really? But that's it? You have a T, and ?, the word extends or super. Damn! bob > Why not use instanceof? bill > You can't because of erasure! bob > Erasure? The electronic group from the 80s....I kind of liked them. ♪I tried to discover...A little something to make me sweeter...♪ bill > Stop that!! bob > Sorry. bill > No, Type Erasure. When a generic type is instantiated, the compiler translates those types by a technique called type erasure — a process where the compiler removes all information related to type parameters and type arguments within a class or method. bob > Why would you do that? bill > Two words. Backwards compatibility. bob > That's doesn't help us. bill > Welcome to Generics in Java. bob > I knew we should have written this in Ruby!

JSON, do you have an invalid label error?

2009-06-25T15:45:00.000+01:00

Invalid label error while evaluating a JSON_String? Add parenthesis around the string and you'll be good to go.

var myOject = eval('(' + JSON_String + ')');

The problem with Java Generics is....

2009-06-25T13:10:00.000+01:00

Fucking, fucker, focker, bullshit, piece of shit....fucking, fuckity, fuck! I'm going to .NET.

Suppress Maven Profiles Via Command Line

2009-06-19T12:16:00.001+01:00

Say you have an active development.profile with, for example, database settings. To change this in versions of maven older than 2.10, you would have to change where you defined your active profiles. (settings.xml, pom.xml, or profiles.xml) However, with maven 2.10 and onwards you can use the minus symbol ( - ) to suppress your active profiles on the command line. This is handy if you want to, for example again, run jetty:run against a different environment.

mvn -Pstaging.profile,-development.profile jetty:run

This suppresses my active development.profile and activates my staging.profile

Schema Translation For Quick InMemory Integration Tests

2009-05-07T11:21:00.000+01:00

In a previous post, I highlighted the time wasted waiting for integration tests to run against a full database. I proposed the idea of running integration tests against an InMemory database locally and a full database in CI. These are the steps I did to achieve this goal.

Creation of unitils.dbmaintainer.script.ScriptSource classes
Transform schema files using regular expression
Configured Unitils.properties
Reconfigure the JpaVendorAdapter
Use Number for queries that use count

ScriptSource Classes

Unitils' default ScriptSource implementation uses the file system to load schema files. I found this annoying because I would have to configure the location of the schema files with a full path. As this project is maven based and shared between a team, full paths are pointless unless you force the team to check out in exactly the same place. Therefore I created my own version of DefaultScriptSource, where the schema files are loaded using the Spring DefaultResourceLoaded. That way I can use the classpath prefix in the unitils.properties file. Another addition to the ScriptSource implementation was preprocess method to translate schema from one database type to another. This method is called in the createScript method, just before the Script class is created.

protected Script createScript(List parentIndexes, File scriptFile) {
...
String preprocessedScriptContent = preprocess(scriptContent);
return new Script(scriptFile.getName(), preprocessedScriptContent, version);
}

Next I extended my version of the DefaultScriptSource class, overriding the preprocessor method. I called this new class, MySqlToHyperSonicAdaptingClasspathScriptSource, for want of a better name! The preprocess method uses regular expressions to translate the schema from MySQL into HSQLDB statements.

Transform schema files

There are many differences between MySQL and HSQLDB statements and I didn't do a complete transformation. I only did the following.

int sizes removed
bit sizes removed
unsigned removed
long blob replaced with object
modify to alter column
engine statement removed
foreign key checks removed
reordering of default values
removed quoted reserved words
change column to rename column

Unitils.properties

This is the checked in unitils.properties file, the version the local integration tests use.

org.unitils.dbmaintainer.script.ScriptSource.implClassName=domfarr.unitils.script.MySqlToHyperSonicAdaptingClasspathScriptSource
dbMaintainer.script.locations=classpath:/database/schema
dbMaintainer.generateDataSetStructure.enabled=false
dbMaintainer.fromScratch.enabled=true
dbMaintainer.dbVersionSource.autoCreateVersionTable=true
dbMaintainer.autoCreateExecutedScriptsTable=true
DatabaseModule.Transactional.value.default=commit
updateDataBaseSchema.enabled=true
jpa.persistenceProvider=hibernate

database.dialect=hsqldb
database.driverClassName=org.hsqldb.jdbcDriver
database.url=jdbc:hsqldb:mem:aname
database.userName=sa
database.password=
database.schemaNames=PUBLIC

# Add this file in your home directory for custom db settings
unitils.configuration.localFileName=unitils.properties

The last line is important. This line loads another unitils.properties file located in the users.home directory. Any values in this file override any previous values configured. Locally you do not have this file, it is not checked in, and is outside of the project. However, the CI machine does have this file and it overrides to configure a MySQL database. It also uses my own version of DefaultScriptSource which does not preprocess the schema files.

database.driverClassName=com.mysql.jdbc.Driver
database.dialect=mysql
database.url=jdbc:mysql://123.123.123.123/bamboo
database.userName=bamboo
database.password=bamboo
database.schemaNames=bamboo
org.unitils.dbmaintainer.script.ScriptSource.implClassName=domfarr.unitils.script.ClasspathScriptSourceocessedScriptContent, version);

JpaVendorAdapter

When configuring the JpaVendorAdapter, I use spring, it asks for the dialect. Remove this entry, this basically works without it and you don't have to worry about filtering this file using maven.

Queries that use count

If you have a createNativeQuery that uses count, for example:

select count(distinct id) from companies inner join companies_relations on companies.id = companies_relations.parent_id"

Don't return the database specific class. MySQL returns BigInteger, HSQLDB returns Integer, return Number, the super class.

  public int size() {

int count = (Integer) getJpaTemplate().execute( new JpaCallback() {
  public Object doInJpa(EntityManager em) throws PersistenceException {

    Number count = (Number) em.createNativeQuery(
        "select count(distinct id) from companies inner join companies_relations " +
        "on companies.id = companies_relations.parent_id").getSingleResult();

    return count.intValue();

  }
} );

return count;
}

Okay...did you make it this far? If you did, nice work. This post is way longer than I wanted, but I hope it works for you. If not let me know and I'll do my best to help out.

Rod Bobble Head

2009-05-06T11:07:00.000+01:00

When this book came out, the image on the cover was a common topic after a few beers. Things have now come full circle with the release of the bobble head.

Too Much Time Wasted Running Tests

2009-04-17T15:20:00.000+01:00

When I arrived at my current project, it had a large stack of integration tests using a combination of Spring, Hibernate, DbUnit and Unitils. The test suite was backed by MySql in all environments. (local, CI and Production.) The problem with this solution is time! It takes anywhere from 3 to 4 minutes to execute mvn clean test on our dev boxes. Now, that does sound like a long time to wait, and I've worked on projects that have taken over 15 minutes to complete the test suite, but it adds up. Multiple that time by the number of times a day a developer runs the test suite, times that by the number of developers on the team, and you start to get serious amounts of time spinning your wheels. I conservatively estimated the team as a whole was waiting over 3 hours a day for the test suite to complete. Beyond these numbers, we use TDD and it is good development practice to check in as often as you can. If the time taken to run your test suite hinders that, you are already slipping into the dark. I set about finding a solution; looking around, asking some questions and some scratching of heads these two options were selected.

Split off the long running integration tests and have them only run under a specific maven profile
Use a faster in-memory database like HSQLDB or H2

Splitting off the longer integration tests does allow the developer to run their tests quicker, but they have to wait for CI to catch any integration test failings. This means if there are errors with integration that code as been checked in. Checked in code that has errors...err. no! Changing to an in-memory database means your schema definition has to change because it will inevitably contain database specific elements. Furthermore, you are no longer using the same database as your production environment, and therefore more testing will have to be done to ensure there are no gotchas when deploying to production due to database change. Neither option sat well with us, so we opted for a combination. Run all tests against an in-memory database in development, but have CI run against a production like database. With this option you get the fast, full test suite locally, and have CI deal with the longer wait that comes with using a production like database. Of course, there is the chance that your CI will still fail, but the likelihood is much lower. How this was actually achieved will be in my next post. This will include how I overcame schema difference without duplication; dialect issues and handling return type class issues from different database drivers.

Tapestry 5 PageTester with Spring Managed Beans

2009-04-13T12:32:00.000+01:00

In pursuit of better test coverage I have been looking into the Tapestry 5 PageTester. However, if you have services that are managed by Spring your pages that have these services injected will run into problems. In a normal Tapestry 5 app that using Spring managed beans the Spring context is loaded via the web ContextLoaderListener. These beans are then picked up by the Tapestry IOC for injecting into your pages. The PageTester doesn't perform this Spring context loading and therefore your injected services will be null. Furthermore, I'm only looking at unit testing here, so I don't want to fire up a bunch of integration type objects. For integration testing look at jitr.org A solution to the lack of Spring beans was to use a TestAppModule class that binds mock services for the PageTester to use.

new PageTester("domfarr.web.tapestry", "",
        "src/main/webapp", TestAppModule.class);

TestAppModule class looks like this.

  public static class TestAppModule {
    public static ContactService buildContactService() {
      return mock(ContactService.class);
    }
  }

I use Mockito as my mocking framework. The PageTester uses the TestAppModule to register my mock contact service and inject it into my page, and the tests have access to the contact service mock object by calling getService("ContactService") on the PageTester's registry.

  @Test
  public void testContactForm() {
    setupMockStubCalls();
    
    Element contactAddForm = startPage.getElementById("form");

    Map<String, String> formValues = new HashMap<String, String>();
    formValues.put("phoneNumber", "555-1234");
    formValues.put("fullName", "Dom Farr");
    
    Document submissionReturnDocument = pageTester.submitForm(
        contactAddForm, formValues);

    Element pageMessage = submissionReturnDocument
        .getElementById("message");

    assertThat(pageMessage.getChildMarkup(),
        equalTo("Contact Dom Farr Added Successfully"));
  }

  private void setupMockStubCalls() {
    ContactService mockContactService = pageTester.getRegistry().getService(ContactService.class);
    
    Contact contact = new Contact();
    contact.setFullName("Dom Farr");
    contact.setPhoneNumber("555-1234");
    when(mockContactService.save(contact).thenReturn(contact);
  }

PageTester SerializationSupport Error

2009-04-11T15:30:00.000+01:00

Using the Tapestry 5 PageTester in your unit tests you will need to add a method to shut it down after each test. If you don't you will get this error.

ERROR SerializationSupport - 
Setting a new service proxy provider when there's already an existing provider. 
This may indicate that you have multiple IoC Registries.

For example.

@Before
public void context() {
  pageTester = new PageTester("tapestry","app", "src/main/webapp");
}
  
@After
public void tearDown() {
  pageTester.shutdown();
}

@Test
public void testStartPage() {
  startPage = pageTester.renderPage("Start");
  assertThat(startPage.getElementById("message").getChildMarkup(), equalTo("Hello"));
}

Surefire plugin, JUnit annotations and Tapestry 5 PageTester

2009-04-10T15:41:00.000+01:00

Tapestry 5 has a nice testing framework which allows you to test your pages and components without the need to fire up a servlet container and do expensive integration tests. If you want to use maven test and junit 4 annotations then you will need to exclude the testng dependency.

<dependency>
  <groupId>org.apache.tapestry</groupId>
  <artifactId>tapestry-test</artifactId>
  <version>${tapestry.version}</version>
  <scope>test</scope>
  <exclusions>
    <exclusion>
      <groupId>org.testng</groupId>
      <artifactId>testng</artifactId>
    </exclusion>
  </exclusions>
</dependency>

Without this exclusion, the surefire plugin fails to see your JUnit tests that are annotated with @Test.

Tapestry 5 if else condition

2009-04-02T14:29:00.000+01:00

You may at some point need to have simple conditions in your tapestry view. Tapestry 5.1 use this version

<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_1_0.xsd" xmlns:p="tapestry:parameter">
<t:if test="loggedIn">
  Hello, ${userName}!
  <p:else>
    Click <a t:type="actionlink" t:id="login">here</a> to log in.
  </p:else>
</t:if>
</html>

Older versions of Tapestry 5 use this version

<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_1_0.xsd">
<t:if test="loggedIn">
  Hello, ${userName}!
  <t:parameter name="else">
    Click <a t:type="actionlink" t:id="login">here</a> to log in.
  </t:parameter>
</t:if>
</html>

Remove Item From Collection

2009-04-01T15:45:00.000+01:00

If you directly remove from an item from a collection you will trigger a java.util.ConcurrentModificationException


Collection<String> mySet = new HashSet<String>();
mySet.add("one");
mySet.add("two");
mySet.add("three");
mySet.add("four");

for (String item : mySet) {
  if (item.startsWith("t")) {
    mySet.remove(item);
  }
}

System.out.println(mySet);

Which will give this.


Exception in thread "main" java.util.ConcurrentModificationException
 at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
 at java.util.HashMap$KeyIterator.next(Unknown Source)

For years, when I had a collection and I wanted to remove a number of items from it I used this pattern.


Collection<String> mySet = new HashSet<String>();
mySet.add("one");
mySet.add("two");
mySet.add("three");
mySet.add("four");

Collection<String> toBeRemoved = new HashSet<String>();

for (String item : mySet) {
  if (item.startsWith("t")) {
    toBeRemoved.add(item);
  }
}

mySet.removeAll(toBeRemoved);

System.out.println(mySet);

Which will give this.

[one, four]

I never really like this and today I bothered to look beyond my nose and found you can remove without the need for the toBeRemoved Collection by using an Iterator and its remove method.


  Collection<String> mySet = new HashSet<String>();
  mySet.add("one");
  mySet.add("two");
  mySet.add("three");
  mySet.add("four");

  Iterator<String> iterator = mySet.iterator();
    
  while(iterator.hasNext()) {
    String item = iterator.next();
    if (item.startsWith("t")) {
      iterator.remove();
    }
  }

  System.out.println(mySet);

This one I like, no need for that silly extra collection object.

Git: You're ugle and stupid if you use anything else

2009-03-31T13:27:00.000+01:00

Source control has been a source of pain in every project I've ever contributed to. In my time I've used CVS, SVN and Visual SourceSafe. CVS seemed okay until there were conflicts or you wanted to delete something. SVN kind of corrected some of the CVS issues, but merging and branching were still a real headache. And I'm going to skip VSS because I don't want to write nasty words in this blog. There are other issues as well. It is very hard to work offline; you can't check code in if it breaks the test suite because it will break everyone else; history of refactors that involve multi files are lost. Git might be the answer. It's from Mr Linux himself so it has good heritage. I found this talk he gave at Google about Git and how you are ugle and stupid if you use anything else. As ever, Linus Torvalds is full of bright ideas, brutal critism of other software and the people that write it, very high priase for himself, and all said with a tongue-in-cheek humour. But strip away the irreverent humour and he has solid points. (yes - I know - this is two years old - what can you do, eh)

When is an ArrayList NOT an ArrayList....

2009-01-09T14:11:00.000Z

....when you use Arrays.asList(T... a) JavaDoc says:

List stooges = Arrays.asList("Larry", "Moe", "Curly");

Would it be reasonable to do this?

ArrayList stooges = (ArrayList) Arrays.asList("Larry", "Moe", "Curly");

Computer says no! Why? Arrays.asList uses a internally reimplements of ArrayList.

private static class ArrayList extends AbstractList

Whatever happened to not reinventing the wheel!

Code Review

2009-01-06T19:45:00.001Z

All change

2008-09-18T18:07:00.000+01:00

Just a quick post. Apologies to my small and faithful readership that I've not posted recently. I am moving back to the UK after 9 years of the wonderful Canadian lifestyle and time is a rare resource right now. I will continue posting while I'm in England and I hope you continue reading and sharing my posts. I'll be back in the UK as of October the 16th, 2008 and will start posting then.

Free Geek

2008-09-10T02:35:00.000+01:00

I stumbled across this recently. http://freegeekvancouver.org Next time you have or hear about a computer that just isn't worth saving, remember these guys and help out. If you want to skip the reading and watch the video. Here it is.

Pair Programming Saves The Day.

2008-09-04T19:12:00.000+01:00

With some good pair programming the new version of Spring IDE (2.1) was released with support for Spring Web Flow 2.0.3. Read Christian Dupuis blog for full story. 21-with-web-flow-2-support-released

Code block formatter for your blog

2008-08-27T17:51:00.000+01:00

You may have notice that the code blocks in my blog entries are nicely formatted and have a snazzy grey box around them.

package domfarr;

public final class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello World!");
  }
}

How do I do them you ask? A god like knowledge of JavaScript and CSS! Well, no. As any pragmatic developer does, I check to see if someone had already invented the wheel. And they have: Format My Source Code for Blogging Remember, someone is always listening. So make your code generic. We don't want your company or client getting all upset because you just posted their new encryption string.

Has Spring entered its Autumn?

2008-08-26T01:30:00.000+01:00

I'm currently working on a new web based application using Spring's contract first style web services, some jpa and simple Spring MVC client. Up to now I've only used extension for web controllers, and mostly extending the SimpleFormController. But as this was a green field I can move up to Spring 2.5.x and with that start using annotated based pojos for my controllers. This all started off really good, until I came to validation of the form. Previously you injected your validator and somewhere in the package hierarchy Spring would call the support method of the validator to make sure it was of the right type. But to my horror using annotated controllers I have to call the support method manually. What happened to abstracting calls away from your implementation. This the example of the 2.5.5 sample pet client application.

  @RequestMapping(method = RequestMethod.POST)
  public String processSubmit(@ModelAttribute("pet") Pet pet, BindingResult result, SessionStatus status) {
    new PetValidator().validate(pet, result);
    if (result.hasErrors()) {
      return "petForm";
    }
    else {
      this.clinic.storePet(pet);
      status.setComplete();
      return "redirect:owner.do?ownerId=" + pet.getOwner().getId();
    }
  }

No DI and no call to the support method! Has Spring entered its autumn, will all the leaves be turning brown. I doubt it, Spring has a great many things to offer jee. However, Spring MVC is moving in the wrong direction right now and I hope it is corrected soon.

Home and End keys in Eclipse IDE.

2008-08-19T17:45:00.001+01:00

A quick follow up from previous bindings post. There are always exceptions and Eclipse IDE is one of those. If you want the same mappings for home and end keys for Eclipse you will have to change your Eclipse preferences. Goto preferences->general->keys. The only mappings that, in my opinion, are a little strange are top and bottom of the document. These mapping are called Text Start and Text End.

Key Bindings For Mac

2008-08-19T17:04:00.000+01:00

I use multiple OS and switching between then can sometimes drive me round the twist. I'm sure that Apple and Microsoft do this on purpose, but that might be the paranoid android in side of me. If you like your home and end keys to perform a full suite of functions, here are the mappings for Mac OS. Create or edit, ~/Library/KeyBindings/DefaultKeyBinding.dict Add the follow, and save the file.

{
"\UF729"  = "moveToBeginningOfLine:";                   /* Home         */
"\UF72B"  = "moveToEndOfLine:";                         /* End          */
"$\UF729" = "moveToBeginningOfLineAndModifySelection:"; /* Shift + Home */
"$\UF72B" = "moveToEndOfLineAndModifySelection:";       /* Shift + End  */
"^\UF729" = "moveToBeginningOfDocument:";               /* Ctrl + Home */
"^\UF72B" = "moveToEndOfDocument:";                     /* Ctrl + End  */
}

For a full run down of key bindings, check out the Mac OS X Key Bindings

Net Neutrality

2008-08-14T04:09:00.000+01:00

An important message - or - conspiracy theory

Maven Jetty plugin and security realms

2008-08-11T18:37:00.000+01:00

I often use the Jetty plugin for Maven; it's a super way to speed up development. I'm currently in the process of creating a new web application which will need some basic security. For completeness I wanted to add a security user realm to my jetty configuration. I initially added the realm in Jetty configuration, per the Jetty manual instructions. My realm.properties where being loaded, the Jetty configuration was also without error, but when the Jetty container fired up I get an unknown realm warning. Much wailing and nashing of teeth later I moved the user realm to the pom plugin definition and all is good. Why it didn't work using the configuration file is still a mystery. <plugin> <groupId>org.mortbay.jetty</groupId> <artifactId>maven-jetty-plugin</artifactId> <version>6.1.10</version> <configuration> <contextPath>/bmbo</contextPath> <userRealms> <userRealm implementation="org.mortbay.jetty.security.HashUserRealm"> <name>Bonus Manager Realm</name> <config> src/test/resources/jetty-realm.properties </config> </userRealm> </userRealms> </configuration> </plugin>

Using Textmate as you svn editor

2008-08-10T00:19:00.000+01:00

When running the check in command for svn you have to supply the -m attribute and a string for the comment. If you want to use your favourite editor, you must set an environment variable: SVN_EDITOR If you are on mac and want to use TextMate, use the wait attribute. eg. export SVN_EDITOR=’mate -w’

Needs some space

2008-08-10T00:03:00.000+01:00

If you are writing a jsp in xhtml you can't use normal xml entity references. eg. &bsnp; This is because you can't set entity declarations, like this. ]> You will have to do this. &nbsp;

The hippest tool set

2008-04-16T23:30:00.000+01:00

There is much talk about the hippest tool set at my current employer. And to be honest most of it is tongue in cheek. But enough about our sarcasm, here's a good read. Rod Johnson's Predictions for Enterprise Java

Multiple Forms And The SimpleFormController

2007-12-06T23:25:00.000Z

Some pages will inevitably contain multiple forms. If you use the SimpleFormController from Spring, you will need to override the isFormSubmission method.

By default this controller makes the decision to call the onSubmit method by simply checking the request method. However, if there are multiple forms on the same page and another form posts, your controller needs to understand the post wasn’t for it and it shouldn’t call the onSubmit method.

Overriding the isFormSubmission method allows you to check that the request contains the correct form object. If the form object for the controller isn’t on the request, don’t call onSubmit.

Scott Ambler - Agile In The Real World

2007-09-17T23:10:00.000+01:00

I was able the catch Scott Ambler speak at the IBM Burnaby office today. It wasn't a long talk, about 1 hour or so, but he packed in a great deal of information. Here are my notes.

Traditional Software Design

Academics came up with a bunch of ideas that should work, a theory. Traditional method of: Requirements, Analysis, Design, Program and Test methods mean that validation of the Requirements and Analysis isn't done until the Test phase. Which means that the guys doing the Requirements and Analysis have no clue of the damage until it is too late. Each step information is lost or misinterpreted. The famous quote. Build software like building a bridge. ....but now we know differently.

Agile or Evolutionary method

Agile is not theory, it is based on practice. Less upfront documents. Tests = Specification. High quality software delivered every iteration. Scope creep is good! If you stop feature creep it means you are making software that the stakeholder doesn't want.

Success

80% of stakeholders want what they need, not what the spec designed. B.R.U.F. Leads to Significant Wastage: 45% of features delivered were never used when designing with serial methods. http://www.agilemodeling.com/essays/examiningBRUF.htm Success is not "On time, on budget, to specification." Success is more about delivering quality software that the stakeholder wants today. Spending the money wisely. Deliver working software frequently allows the stakeholders to continually gage the success of a project. Documentation doesn't give value, only delivering working quality software does. More collaboration == more success. White board things often with everyone. Focus on quality...more testing = higher quality. There is no silver bullet, agile requires skilled people.

Developers

Developers should move away from specialization. It isn't effective. Being a specialist means having to hand off things when done. Each time that happens ~25% information is lost. Specialization in 1 or 2 areas is helpful, but have many general skills and domain knowledge. Learn about databases, business analysis, etc.

What you get from Agile

Agile teams are smaller, produce higher quality software that meets the needs of the stakeholders and this basically reduces cost. Agile gives stakeholders control over budget, schedule and scope. Developers give back quality software that the stakeholders want. There are documents in agile. But the type and amounts are chosen smartly. Documents are about stable ideas. There is nothing speculative about agile documentation, which is how traditional methods approach documentation. If you do TDD your tests will be the specification. Every iteration the stakeholders can see if the deliverable is where they want to be. With this information they can govern the spending. But the stakeholders have to know what they want and developers have to deliver quality software every iteration. Repeatable results, not repeatable process. Addresses the risk early.

Must Dos

Learn at the end of iteration. Refactor every iteration. Just in time planning. You can only predict the short term. Continuous Integration. TTD Use static debug tools. Reduce solo development - you must pair!

Example

Eclipse is a very successful agile project. It has delivered its major release on time every year. Google "Eclipse Way Process" to see the Eclipse agile practice. Eclipse does a 6 week iteration due to very distributed workforce. Iteration Stats. 2 wks iteration 32% 4 wks iteraton 21% No need to be longer then 4 weeks unless.

Not everything is green field

Agile needs to cope with entrenched process, legacy code, and governance of IT. Traceability is needed sometime, up front modelling needed sometimes, depending on the project type.

Company

Find out how to motivate developers. don't heard cats. Don't enforce standards, find out what standards people want to follow. Each team should own their code. Have a small number of project metrics, too many is bad. Defect trends and burn rate are good. These show a team is delivering value or not and the stakeholders are getting value for money or not. Help teams that need it. Get ideas from teams that are doing well. Spend money wisely. Ask....how well has it worked in the past. Staged finance is another option, try it compared to annual budgets. HR should reward quality of delivered software, not just years of service.

Eclipse and SVN

2007-06-20T23:04:00.000+01:00

There are two Subversion plugins for Eclipse, Subclipse and Subversive. I much prefer the latter, Subversive in my experience is closer to the CVS plugin for Eclipse which rocks. Subversive plays well with maven2 multi-projects and allows you to have the parent as a general project side by side to the child Java projects in your workspace. That alone gives it a major head start over Subclipse which fails badly when you try to have the two projects together in the workspace. However, Subversive has had a few issues of late and it has had me screaming blue murder at any software developer. But with calm collection I've found the magic combination of things you need in order to have this plugin work. Update your Mac's SVN installation to the latest version 1.4.4. You can get a binary install from here: http://downloads.open.collab.net/binaries.html Update the Subversive plugin in your Eclipse to the latest version. Eclipse Update Site: http://www.polarion.org/projects/subversive/download/1.1/update-site/ Configure your Eclipse Subversive plugin to use Native JavaHL client. You should be good to go. :)

Spring JNDI datasoure binding for testing

2007-06-11T22:49:00.000+01:00

Use the SimpleNamingContextBuilder in Spring. It's really simple and very handy. SimpleNamingContextBuilder builder = new SimpleNamingContextBuilder(); DataSource ds = new DriverManagerDataSource("com.db.Driver","jdbc:db2://db.url.com:1234/","username", "password"); builder.bind("java:myDB", ds); builder.activate(); Now when you use the jee:jndi-lookup in your Spring configuration. e.g. <jee:jndi-lookup id="dataSource" jndi-name="java:myDB" />

Do you know the other Bob?

2007-05-30T22:44:00.000+01:00

Crazy Bob, that is, not Uncle Bob. While doing a little reading on Spring I found this old blog post by Crazy Bob : I don't get Spring. You don't get Spring? What? And who the hell is Crazy Bob? What's not to get about Spring I thought. But after reading the post, he brings up some interesting points which I'm still marinating on. It's a long post, but a good read. Crazy Bob, BTW, is the creator of Guice.

Squeeze every last ounce

2007-05-01T22:37:00.000+01:00

If you are looking to optimize your code for speed during production, and I'm assuming you don't log at debug in production, make sure you wrap your debug log outputs with the isDebugEnabled() check.


if (log.isDebugEnabled()) {
log.debug("Count :" + counter);
}

The performance gain is considerable when not logging at debug. eg. production. A debug call without check = ~440 nano sec. A debug call with isDebugEnabled: ~20 nano sec. The reason is that it is much quicker to check a boolean than create the log string. Without the check, the log string is created anyway and then discarded by the logger when it checks if debug is enabled. The flip side to this is that you incur a 20 nano second overhead when you are logging at debug....but that is a price worth paying for production speed. Before any smart comments come in about concatenating strings....I agree you should use StringBuilder to create the strings for logs if they contain variables. :)

Maven eclipse and double classpath entry

2007-04-27T22:34:00.000+01:00

When creating dependencies in your project's POM the type element is not required for a dependency element. It is important to include the type element if the dependency is of type ejb. <dependency> <groupId>bodog.platform</groupId> <artifactId>mailer-ejb</artifactId> <version>${platform.version}</version> <scope>provided</scope> <type>ejb</type> </dependency> Executing mvn eclipse:eclipse without this type element can lead to double entries in your eclipse .classpath file. This happens with inconsistent definitions of the dependency, as the eclipse:eclipse plugin creates entries for both ejb and jar types.

Script tag. Which is correct?

2007-03-01T22:19:00.000Z

Which is correct? <script type="text/javascript" src="/account-info.js"/> <script type="text/javascript" src="/account-info.js" > </script> Although both legal xml, the first tag will not work correctly. If you use the script tag with src attribute you need to have the full open and close tags. If I was to hazard a guess as to why .... The src content is injected between the open and close tags, which cannot happen if you chose to close within the open tag.

Couch Potatoes Mourn

2007-02-22T22:15:00.000Z

Next time you sit down and grab that remote, spare a moment for Robert Adler. Robert Adler was a physicist and prolific inventor, he died on February 15 at the age of 93. He is best known as the co-inventor of the television remote control.

Do we need another simple text format

2007-02-09T22:02:00.000Z

Maven projects have a nice plug-in called site. This plug-in is used to generate the documentation site for your project. That’s great! What isn’t great is APT: Almost Plain Text. APT, as its name suggests, is a very simple text file which, with some simple formatting tricks, can create the HTML output for your site. This is a good idea if you only want to have headings and bullet points. If you want anything else, I’d stay clear of this option. Table and hyperlink are far from simple, and heaven forbid you want sub items. I suggest using xdoc.