What is web service

Software system designed to support interoperable machine-to-machine interaction over a network.

Three keys:

1. machine to machine (todo service is not)
2. Interoperable (not platform dependent)
3. Over a network

Different kinds of web services

SOAP

Use XML as exchange format

Adhere to Structure: Envelope - Header - Body

REST

The format of request/response is HTTP

resources

A resource has an URI, it is what you want to present in your application

A resource can have different representations

• XML
• HTML
• JSON (most popular)

Define and perfom actions on resources using HTTP POST/GET/PUT/DELETE

How to build web service

How does applications communicate

Application <==request, response==> web service

How to make communication platform independent? Use data exchange format:

1. XML
2. JSON

Transport:

1. HTTP
2. MQ

Tools

• Browser
• Curl
• Postman

Browser makes it hard to send Post/Put/Delete command, that’s why we use Postman