REST Vs SOAP

Introduction

In the mad rush of implementing Rest Services, I will be discussing about key scenarios for REST Vs SOAP i.e when it is best suited to implement REST Vs SOAP or vice-versa.

Can REST fully Replace SOAP? To answer let's understand what is SOAP and REST?

SOAP – Simple Object Access Protocol.

• Exposes Operations that implements business Logic.
• It provides loose coupling to integrate hybrid systems.
• SOAP supports standard error Messaging
• Designed for:
  • Extensible
  • Distributed Computing
• SOAP service very well suited for Enterprise Applications needs & goals:
  • Supports HTTP, SMTP, JMS
  • Enterprise security with WS-Security
  • Supports ACID, Atomic transactions with WS-AT
  • Lot of development tools available
• Supports HHTP POST
• Supports only XML
• Supports stateless & stateful operations
• Strongly typed.
• Supports asynchronous messaging

REST – Representational State Transfer

• Exposes Resources which represent Data
• Use HTTP methods (GET/POST/DELETE)
• Based on simple Point to Point communication over HTTP.
• Stateless communication
• Supports multiple Formats

Key Advantages of REST?

• REST can be consumed by any client like web browser, AJAX, JQuery, Javascript
• REST is definitely lightweight
  • Doesn't requires XML parsing
  • Consumes less bandwidth
  • Doesn't require SOAP header for every message.

Key Challenges with REST?

• Building a client in REST can be challenging:
  • Can't generate client side artifacts from WSDL as in case of SOAP
  • Need to write raw HTTP calls.
  • Not many IDE available to write REST Clients
• Rest only Support HTTP / HTTPS
• REST is not secure.
  • Parameters are part of the URI
  • No support for acquiring tokens
• RESTFul Services has no contract.
• REST is not reliable
• REST can't be governed as it doesn't have any service registry.

What's is Verdict for REST vs SOAP?

Both REST & SOAP are best suited for following respective scenarios

REST	SOAP
Best Suited for: Web Services. Smaller size messages (Limited bandwidth) Limited resources (No XML parsing required) Exposing data over Internet. Combining content from different sources / SORs in a web browser.	Best Suited for: Enterprise Services High availability WS-RM Supports transactions WS-AT Supports security WS-Security Asynchronous Processing Contract based development Supports interoperability with business applications.

Coming next is REST API Design, till then happy reading and blogging.