Building Hybrid Apps With Java And JavaScript For Android

Mobile development is an important segment of software development, as users spend more than 85% of their time on mobile applications. That’s not the only point there, as it’s not just the user attention that makes it important, but the spending and the increasing expectations from the user’s side. The technology is evolving to respond to that market attention, and the development market has witnessed a lot of rising technologies and new architectures in the recent year that shows promise. There are several online courses like Hadoop or Java tutorials that can be a great start to remain updated on the technology front. Today we’ll stop at the Hybrid applications, learn how they’re made and what makes them different from other applications, and why you might need one for your business or startup, but first, let’s understand the different applications type.

Native Applications

Even though there’s a big fuss surrounding native applications, they are actually nothing new. Native applications are the mobile applications you’re dealing with on a daily basis that are developed with Native tools for your platforms, such as Java and Kotlin for Android and Swift and Objective-C for IOS. They are powerful, and they can make use of most of the features of your mobile gadget, not to mention that they are quite fast and optimized for these platforms.

Progressive Web Applications

The term PWA was only coined a few years ago by Google, to define a new generation of web applications. PWA mixes the native experience with web development and brings a unified rich UX to all users across different devices and platforms. They usually deploy a service worker that makes the magic behind PWA possible, these applications are not available on the app stores, but they could still be installed on the device, and they’re developed with Javascript, React, Angular, Vue and Polymer are popular for the task.

Hybrid Applications

Hybrid applications are built with the same technologies used by web developers, HTML, CSS, and Javascript. In that manner, they are similar to PWA, but on the other side of the equation, they are available in the app stores. In fact, they are very similar to native applications and it’s really hard to tell the difference, thanks to the use of a native container.

Why would like to develop one? Here are the advantages you’d get from developing a Hybrid App:

Faster time to market: One of the biggest advantages of Hybrid Apps and cross-platform applications, in general, is the speed of development. Today, the time it takes an app from idea to release is a crucial factor in the success of the product.

Inexpensive cross-platform development cycle: Hybrid apps are developed primarily using HTML, CSS, JS, which results in reusable code across different platforms and can then be deployed with minimal adjustment needed.

Abundant human resources: Since it’s the same skill set for web and cross-platform applications, it will be easy to find talents that could work both on your web and mobile apps. Most probably your existent web developers would fit the job.

Drawbacks you might be facing:

Performance: While in most applications the hybrid performance would be indistinguishable from the native performance, 3D and HD games and similar apps might suffer some noticeable differences in performance as they are not optimized specifically for these platforms.

Differences in cross-platform: WebKit, an important tool that we’ll explain later, is not equally maintained across different platforms, which of course, translates to a difference in performance and rendering features.

Unavailable advanced features: Hybrid apps depend on the Native-plugins to provide the native functionalities that native apps have access too, if a certain plugin is unavailable or is malfunctioning, you might have to develop that plugin yourself or ignore that feature altogether.

Understanding The Hybrid Architecture

Understanding The Hybrid Architecture(Image Source)

The following picture shows the complete architecture of a Hybrid app, however, keep in mind that a Hybrid app might not necessarily include all these parts

WebView: If you have noticed, sometimes when you use even a native app, you get directed to a web page from a certain anchor text, however, the web app would display inside the application, as if it had its own browser. This is made possible thanks to WebView, which is a Wrapper in Android around the WebKit rendering engine and allows you to run web pages inside the Application.

For a Hybrid app, WebView can be used to host the app itself.

The JS architecture: Since the application uses Javascript at its core, you will most probably be building an architecture similar to the model-view-controller, depending on the JS library you’re using.

JS-Java Bridge: This is one of the most crucial layers that allow the application to gain its native features. It’s the glue that relates the native and the web environment and makes the execution of sync and async APIs possible. It also contributes to the performance, the security, the ease of use.

Java Plug-ins: The Java plugins are the user-defined API extensions that we expose to our JavaScript environment to be able to use certain native features or components.

Native Components: These are the components and the services that you want your Hybrid app to access in order to perform like a native app does. This includes accessing location, native dialogs and showing action bars.

Application data: As HTML5 data storage might not be enough, although being useful for certain situations, the App data is where you’ll want to store BLOBs of custom formats.

Native Business Logic: This is an important architectural aspect of hybrid applications, which is the fact that you get to implement native code for the business logic if you feel that a certain feature is better to implement there, or that there’s a component that you can only access in the native layer.

For Android, this means that you can customize your application with Java to optimize the experience for users, or even to increase the security.