Experiences B{logged}

Android - a new year

2011-01-19T23:11:00.002+01:00

One of my New Year's resolutions is, to develop Android applications, again.

I plan to develop for the Android users some useful and cool applications. As I think these might just be useful for other smartphone users as well, such as iPhone, Blackberry, and so on, I have decided to use PhoneGap.

This is a very promising framework for developing mobile applications, platform indenpendently. I am just through with the tutorial for Android applications using Eclipse. And I am pleasantly surprised.

No hidden tricks, everything went just fine.

Check out the tutorial yourself:

Metahint - intuitive site search

2010-12-17T21:04:00.002+01:00

Metahint is the clever search extension for your website. It is still in Beta, but it is definitely worth trying it out.

Just start typing in the search box on the top-right side of my page, and you will see how easier it is for you to find content you need within my blog. You even get search-hints! And that is so far the best part of it. I think the part which could really make it useful is if it could be integrated as a plugin in Mozilla, making the indexed page accessible not only by installing a widget.

Let's put it like this: it is way better than Google's site search. You can get the widget from metahint.com. Definitely makes site search more fun!

Fixing Rails - Ajax charset issues

2009-08-17T22:37:00.004+02:00

If you are developing a Rails applications with Ajax for an other language than the english, and you need to use the special characters like ä, ö, ü, you may have the unpleasant surprise to experience getting unreadable characters on your HTML page.
This problem is a little pain in the ass, as it took me a couple of hours to get more understanding of it. The problem was not that their aren't many posts talking about the problem and offering many solutions, but none worked for me. I found useful this post, and this one. Go through these posts if you still don't know what the problem is about.

The solution that worked for me:


before_filter :set_charset
def set_charset
  str_type = request.xhr? ? 'javascript' : 'html'
  headers['Content-Type'] = "text/#{str_type}; charset=ISO-8859-1"
end

Memo Game

2008-05-01T19:40:00.003+02:00

I have found the Android developer challenge a really great competition to participate in, all the more the Android platform is going to get real in the near future. In my opinion, the mobile users, as well as mobile sphere have the most to win, from the appearance and rapid spread of the Android platform.

The application I have created is a memory game. It is an exciting board game, to be played for fun at all times. It even makes you think.

The application, through a user friendly interface, offers the users the chance to play the well-known Memory game now on the Android platform.

Currently under the tiles hide images. The user is able to select a theme from the following: car brands, Disney-figures, fruits and flowers.

After the application is started, the game is on. The user needs to click on the tiles appeared on the screen and try to find a pair of matching tiles. If identical images are discovered under two different tiles - a matching pair was discovered. The game continues until all the tiles with identical images are found or the user leaves the game.

The project is hosted by: Code Google under memogame. From there it is available for download for free.

One great challenge for all

2008-04-21T23:54:00.001+02:00

Android Developers Blog: Android Developers Have Risen to the Challenge

As many as 1788 applications were submitted for the Android platform. This shows a great enthusiasm from developers side, as well as eager to take part in challenges: building new applications, implementing new ideas and compete with each other. One great characteristic which makes things happen, and fast.

Android - the real developer challenge

Programmers and software companies

2007-09-06T15:46:00.000+02:00

Paul Graham said:

... it's not merely true that organizations dislike the idea of depending on individual genius, it's a tautology. It's part of the definition of an organization not to. Of our current concept of an organization, at least...

... there is a contradiction in the very phrase "software company." The two words are pulling in opposite directions. Any good programmer in a large organization is going to be at odds with it, because organizations are designed to prevent what programmers strive for ...

The irony is that organizations may end up depending on other organizations, that are potentially considered geniuses on the market. They try not to get to a point to depend on such, this is almost impossible to achieve - although that is the goal.

Read the whole article here on what a good programmer is as opposed to code-producing-replaceable-individuals working in a large organization.

Software engineers

2006-12-30T23:37:00.001+01:00

-- Best jobs of 2006 --

With this post I propose to put an end to 2006, and I thought it would be a good idea to point out one study made by CNNMoney. A research was organized to find out the best jobs and their caracteristics (research done in USA).
I have been pleasantly surprised to see that the Software engineer career ranks highest. Now, I may say it is expected, as among some other factors, growth of IT-markets and rapid development of information technology requires it. If you are in it, you probably agree it is a very competitive branch.
And here are the top 10 jobs of 2006 (in the USA):

1. Software Engineer
2. College professor
3. Financial adviser
4. Human Resources Manager
5. Physician assistant
6. Market research analyst
7. Computer IT analyst
8. Real Estate Appraiser
9. Pharmacist
10. Psychologist

The factors that were taken into consideration are from my point of view pretty cool: job growth, benefits, what is expected (education level, efficient problem and problem related issue handling (e.g. job stress level) and what is required (creativity, problem solving capabilities, flexibility).

And this is how the chart looks like:

Source picture taken from CNNMoney.

Technorati tags: software engineer, best job, technology, salary.

Transactions, concurrency, performance

2006-11-13T08:54:00.000+01:00

In distributed environment performance is an important criteria for software. To achieve performance, we need to make our software work fast and effective. I will try to describe a problem that you may encounter when developing such application, and of course, a solution which may be helpful.

Let's say you have an application in which you need to work with many user data, where frequent database access is foreseen. In this application you need fast access to existing data. As your application is distributed, data access is required from several locations. You may get in trouble for concurrent data access or reading dirty data. Modifications of the same data should be avoided.

An option is to use a database. Although, this will not provide you satisfaction when it comes to performance. Suppose you need to handle data operations. As soon as data is available, it will be processed by your application from the other locations. Concurrent access will be managed by database - transactions will slow you down even more. And it will not make your application performance better. In principal for performance issues using a database is not the best choice, instead using a cahe would be a better choice.

A distributed cache would suit your needs in this case (see JBoss Cache).

O/R operations in cache are performed at high speed. Using JBoss Cache, you can also have your data distributed on many locations. And you will have fast data access, as your data will be replicated and available on the locations you choose to configure. But to increase the performance of your application, you may choose to use or not transactions. Jboss Cache provides the following transaction configuration options (analogous to database isolation levels): NONE, READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ, or SERIALIZABLE (for detailed description of levels please see here). REPEATABLE_READ is the default isolation level used. You should know that Jboss Cache by default is using the pessimistic locking scheme to avoid concurrent data access.

The idea behind using distributed cache and achieving performance is having such a cache structure, where writing reading may be performed without causing exceptions. More precisely, writing to the cache should be performed in the same cache node (read here more about the cache structure) by the application running on a location. This means, you need a cache structure based on the number of the locations your application is distributed on. Creation of the cache should be done on-the-fly: when the application is not available on a location, it should not have a cache entry. Now we have a write-safe cache. As for reading, we can choose from several strategies: you could use the default isolation level, which uses a read-write lock. This you don't need entirely, as you can write your cache safely. So for reading you could use the READ_COMMITTED or READ_UNCOMMITTED values, depending on how your application handles data integrity. But if you handle dirty data and you are for performance, you could pick the the transaction isolation level NONE - where no transaction support is provided. To improve concurrency and performance, you should care for the configurable locking mode OPTIMISTIC, which if is enabled, transaction isolation levels are ignored. With this configuration mode you still have transactions.

The correct configurations, though, are application and requirement specific.

Technorati tags: design, JBoss Cache, transactions, concurrency, performance.

Simply Seam

2006-10-31T18:10:00.000+01:00

Seam, the Next-gen Web Framework. Please see an overview provided by Michael Yuan of a powerful web framework created by JBoss.

Technorati tags: Seam, Jboss, Web Framework.

Best of C++

2006-09-05T10:40:00.000+02:00

These are some really interesting articles you can read over at Artima Developer. They are all about C++, and about the most important things that have been accomplished so far using this programming language.
If you are just starting, these articles provide you an insight, like a little history lesson. I am not stating that C++ is history. I have a good opinion about this language. But, as each of us know, it comes a time when you have to step further. I did, now I am on the Java side.
A tip for starters: make sure you understand and get to know as many languages as you can, but deeply, so you can make the right choice of the language that suits you.

Technorati tags: programming, language, skill, C++, Java.

X-Period

2006-08-28T17:48:00.000+02:00

This has been a long time since I have added a post here. Well, I will explain shortly the reason and let you know of my future plans.
Work - as lots of us know - took most of my time, but then a long summer vacation followed. I think I can consider this the next series of my posts (the new series), as soon enough there will be a year since I started blogging.
I plan to share my experiences frequently than so far I used to and of course, hoping this makes it easier for you.

Code, in general

2006-05-09T10:22:00.000+02:00

Matthew Heusser wrote an article some time ago and he had a really good remark, pointing out that code which is produced is .. well, only produced and not exactly written to be of good quality. I read somewhere posted these days: "Quality pays itself." You probably have experienced this. But with Matthew's words, we don't get to say it too often: "Now that is some fine looking code".
He has some good points when defining beautiful code: code should be readable, focused, testable and elegant.

However I like to take his ideas a little bit further and add that code should be:

readable: good comments, coding styles should be respected, some common formatting styles should be followed
maintanable: variables, methods, classes should have talkative names, so when it comes to feature enhancing and/or refactoring software-parts shouldn't be just a collection of hard to understand, unreadable code
reusable: when it comes to adding new functionalities, especially methods should be organized that they don't contain duplicated code/duplicated logic and already existing feature should be taken advantage of
extendable: functionality should be organized so it is clear where new features fit best, and make use of object-oriented techniques

And code that was written with some consideration is easier to re-use, and to refactor. Code is usually refactored to make it more compact, more readable, as when refactoring code to introduce patterns, it is for later simpler reusablity and extendability.

Adrian Sutton also has put the point on the importance of producing quality code: "The other big advantage of writing beautiful code is that it demonstrates good coding practices to anyone who reads that code and anyone who reads beautiful code immediately has a high level of respect for the programmer and for the codebase. They're more likely to take time to understand problems and contribute fixes if they respect the codebase rather than seeing a mass of uncommented code, swearing at the programmers and going off to find a better written tool."

I don't agree with those people who say that generated software is of high quality when code from one programming language has been ported to a second language. Imagine a software written in Visual Basic and ported to C or Java. Imagine yourself now having to add new functionality to that software - it wouldn't be a dream job.

Finally, I think I have to add here that I am devoted to writing quality code: I am using, among other practices, the refactoring. Here you may find the catalog of refactoring to patterns, and you should also take into consideration the recently published Refactoring Databases.Of course, you can have the catalog of refactorings from here.

Technorati tags: software, code, programming, refactoring, practices.

Checkstyle - Coding standards

2006-04-04T19:10:00.000+02:00

Quality code in my opinion is an important step towards quality software.

I believe having a well-defined set of coding conventions is necessary. To produce code that is readable, reusable and maintainable, it is needed (among other things like having good programming habits) to follow some code writing conventions. I use Eclipse for my IDE. And with it, Checkstyle - the tool that helps write Java code that adheres to a coding standard.

There exist many coding standars. For personal use, I recommend the easiest form: to follow the Sun coding conventions. Of course, you may personalize it. This will help you in coding and your code, to have a standard format. In case of companies, they tend to have different coding standards: you have probably experienced a few, if you have worked already for a couple of different companies. As companies usually develop their own coding standards, sometimes very different from the Sun coding conventions, other times with minor alterations. This is good in either ways: code within a company needs to be maintained, reused, and improved. So this is a small assurance of better code. When a programmer or programmers have a well defined set of coding standards, they will think less about details such as code layout and variable naming conventions, spending more time on the real coding.

Some coding conventions that I find important:

Comments: all classes, methods, and variables should have
Naming conventions: constants should be in uppercase; variables, methods should have talkative names and should not be abbreviated
(e.g.: private Map myHashMap;);
Declaration: all variables should be declared with visibility modifiers; each declaration should be on separate line

Checkstyle can check many aspects of your source code. You may want to give it try, as it now supports features like: checks for class design problems, duplicate code, and standards related to: Javadoc comments, naming conventions, import statements, white space, modifiers, blocks, etc.

If you already want to add it to your Eclipse IDE, you may find here some hints. As well, you are able to set various highlighting modes.

Technorati tags: Checkstyle, Eclipse, Java, tool, tutorial.

Hermes

2006-01-07T19:17:00.000+01:00

You may have wanted to peak into a queue or topic. Did you find a suitable tool for it? I have used Hermes, and I had a pleasant experience.

Hermes is a Swing application that allows you to interact with JMS providers. Hermes will work with any JMS enabled transport making it easy to browse or seach queues and topics, copy messages around and delete them. It fully integrates with JNDI letting you discover administered objects stored, create JMS sessions from the connection factories and use any destinations found. Many providers include a plugin that uses the native API to do non-JMS things like getting queue depths (and other statistics) or finding queue and topic names.

It offers some nice tutorials of setting it up with the JMS provider you are using. For example, check out the tutorial for setting up Hermes with JBoss 4.X. It can be used as well as a good example for JMS providers configured via JNDI.

Technorati tags: Hermes JMS, Swing, JNDI, tutorial, tools.

EMMA - Code Coverage

2005-11-23T09:42:00.000+01:00

A free Java Code Coverage Tool

Recently I have used EMMA and I have been completely satisfied with the results it provided. Before I started working, I have also tried out the Borland code coverage tool from the Optimizeit enterprise suite, but the tools differ from each other, as well as the reports which are generated. I find the EMMA report easier to overview, and more user friendly. Plus it is free. I guess it can take a little time until you get familiar with it, but it is worth the effort.

"EMMA distinguishes itself from other tools by going after a unique feature combination: support for large-scale enterprise software development while keeping individual developer's work fast and iterative ... " as the "Borland Optimizeit Code Coverage gives developers the confidence that their code is ready to deploy when performance checks are run during development". (Sources: EMMA, Optimizeit.)

Here you can check out two sample coverage reports:

Both tools have the advantage that they can be integrated with Eclipse IDE. Though EMMA does not have a plugin for Eclipse, the way to use it from Eclipse is adding EMMA tasks to your ANT build. You can read the step by step instructions here. Like this you are enabled to run an application from ANT "so that coverage instrumentation is performed on-the-fly, as the classes are loaded by the JVM", and then the same process is repeated by breaking it into distinct instrumentation/execution/reporting steps. What I particularly like about EMMA is the option of separating instrumentation and execution (Offline mode). This is useful when there is a necessity of collecting and merging coverage data from multiple execution runs and multiple JVM processes.

Lance Finney has found EMMA to be a winner-tool: "Emma uses an interesting approach to defining coverage that often results in lines being only partially covered. For example, lines with ternary operators with only one branch executed will show as partially executed".

Technorati tags: code coverage, Emma code coverage, Ant.

Google - Future is Nearby

2005-10-14T14:09:00.000+02:00

I just had this thought: when you want to find more information on a person, on a concept, on a book or even on some corporation, I guess how you would start your quest would be is you startup a browser and you type in all the address, or just some letters, or with some special key combination you get it in front of you: the Google search engine. It is not unusual to use other engines, but I think Google is preferred to others by most of us.
And what if you want - suppose in the nearby future - to find some information on Google itself. Information on their history, on the services they offer, on the projects they are involved in. Which engine will you use to execute your search? I just think it is rather interesting to search on Google with Google. I guess you don't think you will have to.
I see Google growing and offering more and more web services. And there is no sign to show the opposite. Don't forget, we already can have our own personalized Google homepages.
Nevertheless, futuristic ideas already exist on Google, as well the sketch of their homepage. Ckeck it out.

Technorati tags: Google.

Ruby and Eclipse

2005-10-13T18:00:00.000+02:00

Recently I have heard only good things about Ruby. You know Ruby, right? Just in case, you can check what Ruby exactly is. In two small words I can say that Ruby is both a simple and a powerful language.
If you may want to learn more about Ruby, I think you should start in one of these places: http://www.ruby-lang.org or http://www.rubygarden.org.

And as it always gets nicer, you can also develop web applications in a web application framework written in the Ruby programming language. This web application framework is Ruby on Rails. As is the language, so is the framework: it tries to be as simple as it can get and unlike other frameworks, it allows real-world applications to be developed in less code - from scratch - and with minimal configuration.
I came across a site which helps you set up a Rails Development Environment on Windows using Eclipse. The site gives you help in various aspects: getting Ruby, configuring Eclipse for Rails, help with several tools and plugins, even debugging and troubleshooting. And the site will be updated with other interesting features.

Do remember the creator of Ruby: Yukihiro Matsumoto, whose intent was to maximize the joy of programming.

Technorati tags: Eclipse, Ruby, Ruby on Rails.

EclipseCon 2006

2005-10-05T18:53:00.000+02:00

Being an Eclipse user, I would also like to promote EclipseCon 2006: the next technical and user conference focusing on the power of the Eclipse platform.
I believe many of you will attend, and have an extraordinary experience.
I do wish I could also be present.

Technorati tags: Eclipse.

Guest map - Google map

2005-09-26T16:28:00.000+02:00

I guess it is no surprise how you can navigate around the world with the Google Maps.

Recently I have bumped into an interesting use of the Google Maps, namely the Guestmap which can rather give you an idea where may be located the persons on the globe who may read your blogs.

You can find my GuestMap following
the link.

Technorati tags: Google Map, Guest Map.

About Unit Tests

2005-09-23T19:07:00.000+02:00

Recently I have written many tests to make sure the functionalities I have implemented were running okay. I wanted to test small parts of my code if they are doing what they were supposed to do: these tests are called by most of us unit tests. When you test a stand-alone component from the outside, meaning you don't explicitly use knowledge of the internal structure, you are using the "black-box" design technique. In this case you may call your tests component tests.

Michael Feathers wrote an article about unit testing rules and has tried to pull a line between the real unit tests and the tests that are not unit tests. In my opinion, unit tests should avoid talking to a database, communicating across network, etc. However, when you write tests that do this, so the unit-test-concept should not be violated, you may name your tests with the purpose of their creation: component tests, integration tests, performance tests, etc.

Unit tests should always run fast whenever we re-test our code - in this point I totally agree with Michael Feathers .

Technorati tags: Eclipse, Unit-test.

Eclipse IDE

2005-09-13T18:45:00.000+02:00

The IDE I use makes it really easy to develop applications. I am sure that there are others, too, who have already tried it out and sticked to it.
And on top of all, it is free-quality-software. I am most definitely convinced that the open-source community is proud to own such tools.

A little bit about the creation of the IDE: "The Culture of Shipping", the development process that is used to deliver Eclipse is really thought as to create a quality product and to build a community around the product.

Depending on what you are up to, you have many options in tunning it up with plugins that will help you in the development process, besides the great built-in features it has.

Nevertheless, using it to develop enterprise applications with an application server like JBoss, which I don't need to say, open-source as well, enables you to develop quality products, and fulfill the future requirements of todays applications. And getting so far, you can always use Eclipse to debug remotely your application, while you get into a bug.

Technorati tags: Eclipse, JBoss.

Start-off

2005-08-22T11:36:00.000+02:00

Well, the name of my blog-page gave me a little headache, hope the thoughts and the experiences I shall share will be easier to edit and helpful to lots of us.