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Changing source code at run-time with Service Locator pattern

I have a service to get some data but the result can be different basing on where the implementation is. Technically, I have two or more concrete implementation of an interface and I am able to switch using these concrete classes at run-time. That means I have a place to configure it without re-deploying the application. In order to overcome this issue, I use Service Locator design pattern and here I only care about two advantages below: Encapsulating the specific implementation, we just declare the name and don't care about the implementation of the service. Changing the implementation at run-time. Client : an object that invokes the services via Service Locator Business services : services that is used by Client.

My impression of Google I/O 2016

I have not yet had a chance to attend this event but I just watched it on Youtube as usual. :) Google Assistant You might be very familiar to Google Now if you're Android fan. I saw that Google Assistant is like an upgrade to Google Now. It looks smarter because we are able to make a conversation with Google rather than just saying "Ok Google" and getting the tasks done as Google Now. That means Google Assistant can understand our personal words in our contexts. For example: I : Who is Google CEO? Google : Sundar Pichai I : Show me his awards => Here I don't need to say "Show me Sundar Pichai awards", because I don't know to pronounce his name correctly. :) I am thinking about that we can compare Google Assistant to Siri of Apple. Google Home At Google I/O 2015 last year, Sundar mentioned about working on a exciting project with Internet of Things and I think Google Home is a result. Working with Google Assistant, Google ho

JSF 2 - Dynamically manipulating the component tree with system events

Let's suppose we want to modify the metadata (attributes) of elements such as render , requried , maxlength but we do not define in JSF tags. The manipulating components can be conducted in Drools files, for example. How could we do? I think that is what we need to change something of component tree during JSF life-cycle. JSF supports event handling throughout the JSF life-cycle. In this post, I use two events: postAddToView for scanning components tree and preRenderView for manipulating the meta of components before rendering to GUI. I modified my own project from previous post for this example. This is my first further JSF trying out with the project as I said before. :) We define the tags f:event below the form - a container component of the components which we want to work on. The valid values for the attribute type for f:event can be found from tag library document of JSF 2. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:

The HelloWorld example of JSF 2.2 with Myfaces

I just did by myself create a very simple app "HelloWorld" of JSF 2.2 with a concrete implementation Myfaces that we can use it later on for our further JSF trying out. I attached the source code link at the end part. Just follow these steps below: 1. Create a Maven project in Eclipse (Kepler) with a simple Java web application archetype "maven-archetype-webapp". Maven should be the best choice for managing the dependencies , so far. JSF is a web framework that is the reason why I chose the mentioned archetype for my example. 2. Import dependencies for JSF implementation - Myfaces (v2.2.10) into file pom.xml . The following code that is easy to find from http://mvnrepository.com/ with key words "myfaces". <dependency> <groupId>org.apache.myfaces.core</groupId> <artifactId>myfaces-api</artifactId> <version>2.2.10</version> </dependency> <dependency> <groupId>org.apache.myfaces.core<

How to apply Lean - Kanban for your business

This is the topic of Scrum Breakfast meetup this time, speaker: Ms. Phuong Bui - Technical Project Manager of YOOSE Pte. Ltd. http://www.meetup.com/Scrum-Breakfast-Vietnam-Agile-and-Scrum-Meetup/events/230313727/ Lean comes from Lean manufacturing is a method that focuses on elimination of wastes. In other words, this is a set of principles for archiving the quality, speed and customer alignment. The first time I knew about the term "Lean" is from the book Software Craftsmanship . Sandro recommends if we want to transform our pet projects into a real business, we should get familiar with Lean Startup concepts. In this talk, Ms. Phuong pointed out some major wastes includes information (ex: unclear requirements), processes (ex: waiting), physical environment and people. Knowing what the problems should be the best way to eliminate them. The difference between Single item flow and Batch processing is the second main point; and it is the Lean's idea. Batch pr

A simple way to mock objects without using mock unit testing framework

When writing unit test, there are some cases that I have to mock objects: It makes sense to mock provided objects by libraries (APIs) such as FacesContext (JSF) because of no real environment running. It makes sense to mock a lower layer objects and it is already tested, for example: mocking Dao layer objects when testing Service layer (Service calls Dao) . At beginning I was aware of Mockito (a mocking framework) in order to overcome the issue. And currently, I am interested in another way like an alternative because it looks more simple. That is just create mock objects manually and just do anything we want. I've just known this approach from Primefaces' source code. :) Follow my simple example below and we can see what different from these 2 ways are: I have an interface Foo and a class Bar public interface Foo { String greet(); } public class Bar { public String greet(Foo foo){ return foo.greet(); } } Using Mockito example: public class M

Agile Testing - A defense system from my team stories

Today, I love to tell you about my team story about testing. That started from no testing to extreme testing system. eXtreme Feedback Devices (https://jenkins.io/blog/2013/09/05/ext reme-feedback-lamp-switch-gear-style/ ) Guess what? That is really an exciting idea from the picture(no?). These devices can work with Jenkins. Whenever they build a Jenkins job, this system notifies instantly to developers the status of their system. That is not 100% related to testing but somehow it is like our testing mindset. Because, in my team, we call our testing system is a defense system :). There is no doubt that it is very hard for us to remember all features of our applications even which is developed for a long time. Like a document, tests help us make sure no features will be lost after changes such as adding new more features, fixing bugs or refactoring code. That was the reason why we cared much about testing. It was really important for developing apps. Back then, we th