From JSP to AngularJS

Our team maintained a project that was used a quite old web technology JSP. Our project likes a web portal that can contain some other smaller projects, I called it a module. Now, our customers want to add a new module into it.

We met a problem is the current projects can't be testable and hard to maintain because both the logic and GUI are mixed together by using JSP and JSTL. It was really a messy project structure. Therefore, we didn't want to continue this approach. Testing is very important, as well as a good structure for maintenance. We would like to apply MVC pattern for testable and maintainable ability purpose. Yeah, that was actually time for changes.

Our project structure can't be testable and has poor structure.

We listed out some options:

Refactoring all current modules -- terrible approach, too much efforts, too risky due to a lot of modules.
Using MVC just for the new modules with Servlet for Controller, Java class for Model and JSP for View -- actually, it was impossible for us also because our back-end technology was covered by Axon.ivy, the Servlets were fixed and we didn't want to modify a lot without Axon.ivy's official ways.
Finding a new front-end frameworks that can work with Axon.ivy and apply MVC also -- it seems a best solution, we just should learn a lot by choosing this approach.

We found AngularJS is one of the best choices in that time. we did a quick research and we found AngularJS can help us using MVC. Moreover, we can test with Javascript by using some Javascript test framework, likes Jasmine. We also can setup a Jenkins job for auto-run tests by using Karma.

We used AngularJS and some related technologies to overcome our problems.

That was cool and we decided to go for it.

Comments

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...

Performance of a Data Structure

Why data structures matter The fact is that programs are all about processing data. Data structures are referred to how data is organized which affects the time of executing a program. How to measure the performance of a data structure In order to measure "how fast"/efficiency/performance of a data structure, we measure the performance of its operations. There are four basic operations including reading , searching , insertion , and deletion . A pure time consuming is not used for the measuring because it is not reliable depending on the hardware that it is run on. But instead, we use the term time complexity which refers to how many steps an operation takes. An example of how a single rule can affect efficiency Let's compare two data structures: Array and Set (with N elements). 1. Array - Reading : 1 step (because the computer has the ability to jump to any particular index in the array) - Searching : N steps (the worst case with linear search) - Inserti...

Using Drools to Dynamically Manipulate Metadata of JSF Components

The post is just an approach to change metadata (e.g maxlength, required, etc) of JSF components (e.g. inputText, selectOneMenue, etc) by Drools. Project structure Tools being used Java version 1.8.0_131 Apache Maven 3.5.0 Apache Tomcat 8.0.16 Don't forget to configure your confidential information on these following files: pom.xml, settings.xml (Maven) and tomcat-users.xml (Tomcat). For example: Source code https://github.com/vnnvanhuong/java_lab/tree/master/jsfdrools

Monday vhandit #2

Introduction to OpenLDAP directory service "A directory is a specialized database specially designed for searching and browsing, in addition to supporting basic lookup and update functions" A directory service can be local, providing a restricted context; or global, providing service to a much broader context. Curlie is a good example of a directory service. LDAP (Lightweight Directory Access Protocol) is a protocol for accessing directory services , specifically X.500-based directory services. OpenLDAP is an open-source implementation of LDAP. Writing system software: code comments I have read Clean Code (by Uncle Bob) and I thought that I should void comments since the code it explains its implementation itself. That is right but not always true. In this post, the author categorized the comments into 9 types. Only "trivial comments" and "backup comments" are the ones that should be avoided. I myself agree with "writing good comments is harder tha...

Regex - Check a text without special characters but German, French

Special characters such as square brackets ([ ]) can cause an exception " java.util.regex.PatternSyntaxException " or something like this if we don't handle them correctly. I had met this issue. In my case, my customers want our application should allow some characters in German and French even not allow some special characters. The solution is that we limit the allowed characters by showing the validation message on GUI. For an instance, the message looks like the following: "This field can't contain any special characters; only letters, numbers, underscores (_), spaces and single quotes (') are allowed." I used Regular Expression to check it. For entering Germany and French, I actually don't have this type of keyboard, so I referred these sites: * German characters: http://german.typeit.org/ * French characters: http://french.typeit.org/ Here is my code: package vn.nvanhuong.practice; import java.util.regex.Matcher; import java.util...

vhandit

Search This Blog