Mastering FP and OO with Scala

Making use of functional and object-oriented programming on JVM

REST Clients (for Working With REST Microservices)

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It’s so engaging to learn things while learning others. So is the case with the new architectural style REST microservices and developing them using Scala language and tools.

As there are a lot of REST interactions – sending requests to and receiving them from REST microservices – as much as I’m not really in need to comprehend every bit of the communication format, I do need tools to work with them effectively, i.e. be able to create and consume HTTP packets with JSON payload with little to no effort.

HTTPie (pronounced aych-tee-tee-pie)

I’ve been using curl for so long that I hardly remember when it all began. It’s a very handy tool, alas too complex at times.

Not so long ago I stumbled upon another command-line tool called HTTPie. Installation on MacOS X with brew was just brew install httpie away.

➜  ~  brew install httpie
Warning: httpie-0.9.1 already installed

HTTPie describes itself as:

HTTPie (pronounced aych-tee-tee-pie) is a command line HTTP client. Its goal is to make CLI interaction with web services as human-friendly as possible. It provides a simple http command that allows for sending arbitrary HTTP requests using a simple and natural syntax, and displays colorized responses.

The tool’s so simple and intuitive that I’m still fighting with my thoughts to believe that people could still be using curl. I for one was using curl for so long that I almost lost the ability to sense how much pain I was experiencing with curl. I did get used to it and didn’t notice I’m sufferring an enormous pain.

GET requests are pretty similar in both tools (still think httpie is simpler).

http -v --json localhost:9000/api/person

Where the difference shows up is to send POST requests with JSON payload as application/json (-v is to verbose the communication):

➜  ~  http -v localhost:9000/api/person name=jacek
POST /api/person HTTP/1.1
Accept: application/json
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Length: 17
Content-Type: application/json; charset=utf-8
Host: localhost:9000
User-Agent: HTTPie/0.9.1

    "name": "jacek"

HTTP/1.1 200 OK
Content-Length: 21
Content-Type: application/json; charset=UTF-8
Date: Thu, 12 Feb 2015 09:35:46 GMT
Server: tmprl

    "name": "jacek"

First, I don’t have to express it explicitly that I’m going to send a POST request since the key=value pair (in the example earlier name=jacek, and there could be more) implies so. Less typing, less errors.

Second, I don’t have to build the JSON payload myself, key=value pairs are enough to inform the tool to create one for me. Less typing, again.

And the last but not least, colorized responses (aka formatted and colorized terminal output). That could’ve made a difference and it did!

Just these three features made httpie an indispensable tool for me.

httpie has changed how I test my REST microservices using JSON now. As is JSON to REST microservices, so is httpie to the new architecture.


It appears that command-line tools are not always at a premium, and having few GUI tools might be of help at times.

Just a couple of days ago I saw Postman - REST Client being used by a teammate. And it wouldn’t have been any special if I had not heard about the tool from another person during my presentation about REST microservices with JSON – just a day after I’d seen it the very first time (!) Coincidence? Don’t think so!

Postman is a plugin for Google Chrome so the installation went smoothly. Just a click and it’s done. You should give it a go, too (unless you’ve already done and have few remarks to share in the comments to the blog post - I’d appreciate it very much).

Advanced REST client

What made the situation more interesting was that even though Postman was mentioned few times here and there, it seems that Advanced REST client beats Postman by the number of stars - 6791 vs 2635. Why is so?! It’s over 200%! How could that be that Postman is more famous (in my circles) without Advanced REST client being even mentioned?!

It’s installed and I’m going to give it a whirl, too.

What are your tools to work with REST microservices with JSON as the data format? Let me know in the comments!