Looking back on my 2021

As of this writing, the COVID-19 pandemic still persists. In Vietnam, people have just passed a horrible time of lockdown, we needed to stay at home for nearly 4 months. I have even got covid infected and spent a quarantine time for more than three weeks.

My balcony garden

Tech Lead at UMB Solution (ubitec)

Tech Lead was my official job title at ubitec. I have worked closely with two teams (7 developers in total) for developing two products ubichat and ubibot. My responsibilities were divided into three following roles:

- Software engineer: joined teams to implement/solve several challenging problems

- Technical consultant: for developers, Product Owners, Product Managers, and customers.

- Mentor: grew the teams in both technical skills and soft skills

Mental care

In my spare time, I enjoyed reading books and watching videos. I have been doing "meditation" in ... every moment in my life (no kidding 😊)

The following was my favorite 2021 Youtube channels:

- The Quoc Khanh Show Premium (TQKS Premium)

- Bar stories - Dustin On The Go

- Johnny Trí Nguyễn

Making life easier

This was a tough year due to COVID, however fortunately I could get my car driving license and buy a new house.

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Happy new year, 2022!

Comments

Building a Wizard with Chain of Responsibility Pattern

What is the Idea? We want to create a page that there are some steps and each step has its own business. Users are able to click on a step and its status could be changed. Primefaces owns a component " Wizard " but it it quite hard for us in order to apply our very specific and complicated business domain logic on each step; even we cannot click on a step of this component. We somehow are able to use the component " TabView " works with a strong back-end mechanism. A backend mechanism! what do I mean? Yes, we need it because we want to abstract the behaviors of each step otherwise we will get trouble with many events handling. Obviously, each step has some behaviors such as "next", "back" and "switch' are the same and they are related to each other; but the business of these behaviors can be different totally. That is where the pattern "Chain of Responsibility" can be applied. Step by Step Building It! In this simple pr...

Styling Sort Icons Using Font Awesome for Primefaces' Data Table

So far, Primefaces has used image sprites for displaying the sort icons. This leads to a problem if we want to make a different style for these icons; for example, I would make the icon "arrow up" more blurry at the first time the table loading because I want to highlight the icon "arrow down". I found a way that I can replace these icons with Font Awesome icons. We will use "CSS Pseudo-classes" to achieve it. The hardest thing here is that we should handle displaying icons in different cases. There is a case both "arrow up" and "arrow down" showing and other case is only one of these icons is shown. .ui-sortable-column-icon.ui-icon.ui-icon-carat-2-n-s { background-image: none; margin-left: 5px; font-size: 1.1666em; position: relative; } .ui-sortable-column-icon.ui-icon.ui-icon-carat-2-n-s:not(.ui-icon-triangle-1-s)::before { content: "\f106"; font-family: "FontAwesome"; position: ...

Updates to the Scrum Guide - The 5 Scrum Values

This article is available at blog.scrum.org , here I just quote my favorite points and give my comment at the end of this post. Ken Schwaber and Jeff Sutherland, the creators of Scrum delivered a webinar on their latest update to the Scrum Guide . The update was a simple one, adding the 5 values of Scrum to the Guide: These values sound easy? Well, there are many misunderstandings and common problems when applying these values. Here are some example: Value Misunderstanding Getting the value right Commitment Committing to something that you don’t understand because you are told to by your boss. Committing yourself to the team and Sprint Goal. Focus Focusing on keeping the customer happy Being focused on the sprint and its goal. Openness Telling everyone everything about all your work Highlighting when you have challenges and problems that are stopping you from success Respect Thinking you are helping the team by being a hero Helping peop...

Junit - Test fails on French or German string assertion

In my previous post about building a regex to check a text without special characters but allow German and French . I met a problem that the unit test works fine on my machine using Eclipse, but it was fail when running on Jenkins' build job. Here is my test: @Test public void shouldAllowFrenchAndGermanCharacters(){ String source = "ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ"; assertFalse(SpecialCharactersUtils.isExistSpecialCharater(source)); } Production code: public static boolean isExistNotAllowedCharacters(String source){ Pattern regex = Pattern.compile("^[a-zA-Z_0-9_ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ]*$"); Matcher matcher = regex.matcher(source); return !matcher.matches(); } The result likes the following: Failed tests: SpecialCharactersUtilsTest.shouldAllowFrenchAndGermanCharacters:32 null A guy from stackoverflow.com says: "This is probably due to the default encoding used for your Java source files. The ö in the string literal in the J...

Multiple Inheritance of State and Implementation

Today, I was just curious about why an enum can not extend anything else. I took a look on the Oracle document here , and I found the answer is below: "All enums implicitly extend java.lang.Enum. Because a class can only extend one parent (see Declaring Classes), the Java language does not support multiple inheritance of state (see Multiple Inheritance of State, Implementation, and Type), and therefore an enum cannot extend anything else." I have been learned of it before. But, wait a sec...! Why Java does not support multiple inheritance of state? Since I have worked with other programming languages like C++, I was able to make a class extend some other classes. The short answer is to avoid the issues of multiple inheritance of state . I wonder if other programming languages have these below terms but Java does. Multiple inheritance of state It is the ability to inherit fields from multiple classes. There is a problem and Java avoids it. "For exa...

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