Test email with Subethamail – Mock email without changing code

Most of the applications require notifications to be sent to stakeholders (users/administrators/owners) about application events. The notifications may be in the form of SMS, showing popup messages or email. Out of the various notification options described earlier, Email is the most traditional option. In case of Java, the built-in package of javax.mail provides standard APIs to send email including features of Sending attachments, bcc etc.

While there are Open Source / Freeware / Commercial email servers are available, it is always inconvenient to setup a SMTP server for development. On top of that, security policies at Organization level, prevent developers from accessing Enterprise Email server for development testing. This forces, either commenting code responsible for sending email or turning off the feature in development mode. Few, prefer to wrap an exception due to Email server unavailability and ignore it completely. Here is the list of side-effects, one can notice due to ignoring such a crucial functionality.
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PDF operations using Apache PDFBox without stings

PDF is a convenient way of printing the output and sharing the data with application users. Its ability to scale as per display without distorting the contents, is considered to be the strongest feature over other output formats. As per application requirements, it also becomes necessary to generate PDF at runtime. There are many options, available to do so. Either use reporting tools like Jasper and then using reporting API generate the output in PDF OR if you wish to have finer controls over PDF generation use programming API like iText. iText uses AGPL for Open Source, and it can be pretty fatal, if you really don’t understand its legal terms. Contact someone who understands Open Source licenses. Most of the time, developers forget to pay attention to the licensing model. Developers usually don’t understand what Open source really means, most of them feel its free like air they breath and ignorantly fall into the trap of License violation. Usage of any Open Source software without paying attention to License, can result into lawsuit against development company or hefty payments to the governing company of Open source software. Unfortunately the Illiteracy rate is way too high. Why, I am bragging about all of this, simply the reason is – if you are using iText, be ready to either Open Source your software or pay for use (Once again pay attention to details, don’t just buy any license). OK! so is there really any other option, than just paying bucks. Yes, there is and as usual, Apache is here for your rescue – Apache PDFBox.

Free SSL / HTTPS Certificate with Lets Encrypt

Are you hosting a Web site, which will manage customer data? Is there any sensitive information getting captured on your Web site? If Yes, you must definitely protect your Web site and the trust of your customers by enabling secured, encrypted communication. As a first step towards enabling HTTPS is to install valid certificate from Certification Authority (CA). It has been a tedious process to configure secure channel and a recurring fee also makes people think about the cost of overall process. But thats not a problem anymore, if you wish to enable basic security, LetsEncrypt is here. I came across, LetsEncrypt few days back and found its the most easiest and hassle free approach to enable encryption for a website. And with few steps, I had a website with HTTPS mode ON. Throughout the process of configuring and hosting a sample website, I made use of Vultr, Dot.tk and LetsEncrypt offcourse. You can follow this entire process, without spending a penny. Lets start.
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REST API – How to design?

Are you developing web application? OR building mobile app? what you commonly require is a backend providing the ability to save user data and provide meaningful insight. In addition to storage and retrieval of the data, a secured access control mechanism is required to ensure data integrity. There are multiple approaches to handle the requirement and the implementation varies based on the chosen programming language. Usually, the concepts used to solve this problem fall into following broad categories

Proprietary Implementation (Servlets, MVC Controller, Remote Object etc.)
SOAP services
API development using REST

The intention of this article is to suggest some of the concepts that must be considered while designing REST API. Most of the time, my interactions with Developers and even some of the architects, led me to a realization that most people have limited or no knowledge of REST API design. Some refer merely exposing a data using either XML/JSON is REST, while some think just using HTTP methods is sufficient to build REST based API. But that’s not the entire truth.
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NodeJS dependency injection – Zander

Having worked on Java and Spring for almost a decade, my programs are naturally inclined towards using dependency injection. Recently, I started using NodeJS for developing one of our initiative and I felt modularizing my code instead of building one monolithic program. Soon, I realized that in order to keep my modules loosely coupled with each other, I need to use dependency injection and I started searching for framework. While I tumbled across many frameworks, which claims to provide Dependency Injection, none of them really fit to the expectation that I had. Also I came across many posts emphasizing that NodeJS programs do not require separate Dependency Injection frameworks and one can easily tweak require method to achieve desired results. I personally, didn’t like the suggestions and hence I thought of developing one of my own – Zander.

Swagger – REST documentation made easy

Up until now, REST service documentation was really painful job (believe me, I have burnt my hands with JAX-RS, JAX-WS). So called XML generated by REST hosted servers was partially helpful to understand the operations and skeleton of data structure. Beyond that, the separate documentation in order to understand the sample values and detailed information about operation was still required. Well that’s not all, even if one wants to try out the API, there was need of having separate client. Well, for all this time we continued to create beautiful documentation manually, which definitely was plagued with problems like syncing, version maintenance etc. Luckily, the problem seems to be fading away with the framework, I came across in recent times – Swagger.
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Android – Sliding overlay

While, I was working on one of the Android App, I needed a layout which offers overlay layer and provides a semi-transparent effect to view controls beneath it. In addition to the look & feel, I was also looking for a smooth transition effect to bring overlay in the view. It should also offer responsive touch to slide it out. The requirement seems to be very simple and my hunt began to implement such control. While I could able to locate many references for transition effect, none of them were perfect and had some flaws in it. The major flaw, I noticed with the implementation was that – Once an overlay view is displayed, sliding it to the right, will sometimes cause controls beneath it receiving events and yielding weird results. The rationale behind it was simple, the usage of setOnTouchListener doesn’t provide enough control over the touch lifecycle of a control and hence the touch event was getting leaked to the controls, visible one layer below.
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CarbonRider

You make a matrix, you define the limits.