Downloading images

Downloading an image and displaying it with the help of ImageView can be done in a single line. Since Android development started, this is something that every developer has done. Android is a technology that is more than five years old, so we can expect this technique to be quite advanced and to find-third party solutions that facilitate it. That said, this book wouldn't be called Mastering Android if it didn't explain the process of downloading an image and displaying it without any third-party library.

It is good to use the latest library in your apps, but it is better to understand the solution that you are implementing, and it is even better to be able to build this library yourself.

While working with images, we need to handle everything from network connection to the downloading of array bytes and their conversion to Bitmap. On some occasions, it makes sense to store the images on a disk so that the next time we open the app, these images will already...