Android Image Loading *without* a Library - Common Interview Question

Most Android apps will use an image loading library like Glide or Picasso to fetch remote images and display them in an ImageView. A common interview question is to provide the same functionality without relying on these libraries. This tests being able to work with networking primitives (URL connection + input stream), and dealing with multiple threads (UI thread + background threads).
➤ Code we wrote: github.com/rpa...
➤ Good explainer about handlers and threads: • Looper, MessageQueue &...
➤ This problem and solution are inspired from Codepath: codepath.github...
Hi! I’m Rahul, a software engineer with a passion for teaching. I went to Stanford, was a founding engineer at a startup, and have worked at various companies across Silicon Valley. I’m currently an Android Developer at Facebook and teach an Android class at Stanford. Would love to connect with you! This channel is about tech (especially Silicon Valley), combining tactical how-to guides with interviews.
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📂 Github: github.com/rpa...

[@SuboptimalEng]

Pretty interesting, I never really thought about (or saw videos of) android specific interview questions. I figured LeetCode was the standard 🤔

[@RahulPandeyrkp]

Android dev interviewing depends very much on the company, but in my experience it's usually a combination of leetcode + domain-specific (e.g. questions like this or asking to build something).

[@BharadwajGiridhar]

@@RahulPandeyrkp Very true. Nice video.

[@ganeshrajpadhayay3714]

Glad to find your channel, amazing stuff, keep them coming :)

[@RahulPandeyrkp]

thanks Ganesh!

[@zeusalmighty6740]

Very nicely put video. Keep them coming!

[@RahulPandeyrkp]

Thank you 💕

[@aabhishek4911]

Nice video , you could have added the bitmap scaling part to avoid OOM incase of huge images

[@RahulPandeyrkp]

thanks Abhishek! Yes, definitely a lot more to add here. For the bitmap scaling part in particular there's some sample code in the MyMemory video here: kzbin.info/www/bejne/pICqpHp-rJqcq6M

[@mehulbisht9708]

Great explanation! What if the interviewer also asks how to implement Garbage Collection that the Image Loading libraries provide for recyclerview list items? Or would it be out of the scope of an interview? :)

[@RahulPandeyrkp]

Thanks! For a standard 45 minute interview, I doubt that anyone would expect an implementation of it. However, you could prepare a few talking points about things like GC or caching.

[@khaihoang7420]

@@RahulPandeyrkp Do they allow outside resources during the interview? I find that the syntax is hard to remember.

[@RahulPandeyrkp]

if it's a real coding interview, they should allow outside resources + googling (just like real life interviewing). If it's more of a conceptual/whiteboard test, it may not be allowed

[@khaihoang7420]

@@RahulPandeyrkp and i am a codepath alumni. Guess what? U were a very amazing instructor. The way you taught the material was second to none. Hope u will make a series on android latest stacks and practices soon

[@clo4k661]

Could you please make a course of kotlin beginner to advance? It will really help. Also I see people demotivating you. Don't get demotivate you are doing great.

[@RahulPandeyrkp]

Thanks a lot. I have a few more Kotlin videos planned, I hope they help!!

[@pratiktarade6738]

Great Video... Please make full video on bitmap

[@RahulPandeyrkp]

anything in particular about Bitmap that you'd like to know about?

[@vengateshm2122]

Shouldn't we close URL connection?

[@RahulPandeyrkp]

There is a disconnect on the HttpURLConnection, but not on URLConnection. We close the input stream, don't think there's much else we can do. More details: stackoverflow.com/questions/272910/in-java-when-does-a-url-connection-close

[@mahmoudayman8660]

really awesome

[@RahulPandeyrkp]

Thanks!

[@techworld3043]

Great video ..

[@RahulPandeyrkp]

Thank you!

[@shivamsethi3829]

Great, thanks

[@RahulPandeyrkp]

Very welcome!

[@dubey1akash]

thankyou