Soap vs Rest

SOAP Vs. REST: Difference between Web API Services

What exactly is a SOAP?
SOAP is a protocol that was designed before REST and entered the picture after it had already existed. The primary objective in developing SOAP was to simplify the process by which programmes written in a variety of programming languages and operating systems could communicate and share data with one another. The abbreviation SOAP refers to the Simple Object Access Protocol.

What is REST?

The REpresentational State Transfer (REST) protocol was developed primarily for the purpose of working with components, such as media components, files, or even objects, that are stored on a specific hardware device. A “RestFul web service” can be referred to as any web service that is based on the REST architectural style and concepts. When interacting with the necessary components, a service that follows the REST architecture would make use of the standard HTTP verbs including GET, POST, PUT, and DELETE. Representational State Transfer is what REST stands for in the acronym world.

Difference Between SOAP and REST

Each technique has its own advantages and disadvantages. Hence, it’s always good to understand in which situations each design should be used. This REST and SOAP API difference tutorial will go into some of the key difference between REST and SOAP API as well as what challenges you might encounter while using them.

Below is the main difference between SOAP and REST API






  • SOAP stands for Simple Object Access Protocol
  • REST stands for Representational State Transfer
  • SOAP is a protocol. SOAP was designed with a specification. It includes a WSDL file which has the required information on what the web service does in addition to the location of the web service.
  • REST is an Architectural style in which a web service can only be treated as a RESTful service if it follows the constraints of being
    1. Client Server
    2. Stateless
    3. Cacheable
    4. Layered System
    5. Uniform Interface
  • SOAP cannot make use of REST since SOAP is a protocol and REST is an architectural pattern.
  • REST can make use of SOAP as the underlying protocol for web services, because in the end it is just an architectural pattern.
  • SOAP uses service interfaces to expose its functionality to client applications. In SOAP, the WSDL file provides the client with the necessary information which can be used to understand what services the web service can offer.
  • REST use Uniform Service locators to access to the components on the hardware device. For example, if there is an object which represents the data of an employee hosted on a URL as http://demo.guru99 , the below are some of URI that can exist to access them.

  • SOAP requires more bandwidth for its usage. Since SOAP Messages contain a lot of information inside of it, the amount of data transfer using SOAP is generally a lot.
<?xml version="1.0"?>
  • REST does not need much bandwidth when requests are sent to the server. REST messages mostly just consist of JSON messages. Below is an example of a JSON message passed to a web server. You can see that the size of the message is comparatively smaller to SOAP.
  • SOAP can only work with XML format. As seen from SOAP messages, all data passed is in XML format.
  • REST permits different data format such as Plain text, HTML, XML, JSON, etc. But the most preferred format for transferring data is JSON.


When to use REST?

When it comes to the design of web services, whether REST or SOAP should be used and under what circumstances is one of the most hotly contested questions. The following are some of the most important considerations that come into play when deciding whether or not to employ REST or SOAP API technologies for web services. It is recommended to make advantage of REST services in the following scenarios:

Because SOAP messages have more content than REST messages and hence take a far greater amount of bandwidth, REST should be utilised in situations when network bandwidth is limited. This is because SOAP messages are heavier in content.
REST should be utilised whenever there is no requirement to keep information in a certain state from one request to the next because this is known as statelessness. SOAP is more suited for the task at hand if you need a good information flow, in which certain information from one request needs to flow into another. Take, for instance, any one of the many online shopping websites available today. The customer must typically start the purchasing process by adding products that need to be purchased to a shopping cart on these websites. After that, the contents of the shopping basket are brought over to the payment page so that the transaction may be finalised. One example of an application that has a requirement for the state feature is shown here. The current state of the items in the cart must be moved to the payment page before any additional processing may take place.
Caching: If there is a requirement to cache a significant number of requests, then REST is the optimal approach. Sometimes customers will make multiple requests for the same resource at the same time. Because of this, the number of requests that are made to the server could potentially rise. The results of the most frequently requested queries might be saved in a cache, which is an interim storage site. Therefore, if the client requests a resource, it will initially look in the cache for that resource. If the resources are already available at that time, it will not continue to the server. Caching, thus, can assist in reducing the number of requests that must be sent to a website’s server.
Ease of coding — Compared to SOAP, it is significantly simpler to code REST Services and then put them into action. REST is the approach that should be taken if a solution that can be implemented rapidly is needed for web services.
The next topic that we will cover in this guide that compares SOAP with REST is when to use the SOAP API.

When to use SOAP?

The following situations call for the application of SOAP:

Asynchronous processing and subsequent invocation – if there is a requirement that the client needs a guaranteed level of reliability and security, then the new SOAP standard of SOAP 1.2 provides a lot of additional features, especially when it comes to security. SOAP 1.2 also provides a lot of additional features when it comes to asynchronous processing and subsequent invocation.
A Formal means of communication – SOAP 1.2 provides the stringent specifications for this kind of interaction, provided that both the client and the server have reached a consensus on the structure of the exchange. One illustration of this would be a website for online shopping in which customers first compile their purchases in a virtual shopping basket before completing the transaction. Let’s say that we have a web service that handles the final payment for the transaction. There is the potential for a binding agreement that the web service will only accept the quantity, unit price, and item name from the shopping cart. When faced with such a situation, it is strongly recommended that you make use of the SOAP protocol.
Stateful operations – if the application has a requirement that the state needs to be maintained from one request to another, then the SOAP 1.2 standard provides the WS* structure to support such requirements. This is the case if the application has a requirement that the state needs to be maintained.
The next step in this comparison of REST vs SOAP API will focus on the difficulties associated with using SOAP API.

Challenges in SOAP API

The Application Programming Interface (API) is something that is provided by both the client and the server to one another. This is something that is delivered by the browser in the client environment, whereas in the server environment, it is something that is provided by the web service, which could be SOAP or REST.

Problems with the Simple Object Access Protocol

WSDL file – The actual WSDL document presents one of the primary problems when working with the SOAP API. The WSDL document is what provides the customer with information regarding all of the operations that can be carried out by the web service. The WSDL document will include all of the information, including the data types that are being used in the SOAP messages and a list of all of the activities that can be performed using the web service. The line of code that can be found below is only an example taken from a WSDL file.
?xml version=”1.0″?> definitions name=”Tutorial” targetNamespace=” xmlns:tns= “>?xml version=”1.0″?> xmlns:xsd1= xmlns:soap= \s xmlns=””>
types> schema targetNamespace= xmlns=”> /types> /schema> /types> /types> /types> /types> /types>
<element name=”TutorialNameRequest”> <complexType> <all> <element name=”TutorialName” type=”string”/> </all> </complexType> </element> <element name=”TutorialIDRequest”> <complexType> <all>
a number element with the name “TutorialID” and the type “number”
</complexType> </element> </schema> </types>
According to the WSDL file that was just presented, we have an element that is referred to as “TutorialName.” This element is a component of the element TutorialNameRequest, and its type is String.

Now, let’s say that in order to satisfy the business requirements, the WSDL file needs to be modified so that the TutorialName variable is renamed to the TutorialDescription variable. Because of this, each and every client who is currently connecting to this web service will need to make the equivalent change in their code in order to accommodate the change that has been made to the WSDL file.

This demonstrates that the most difficult aspect of the WSDL file is the tight contract that exists between the client and the server, as well as the fact that a single modification has the potential to have a significant effect on client applications as a whole.

Size of the Document: An other significant obstacle is the quantity of data contained inside the SOAP messages that are sent from the client to the server. Using SOAP in environments with limited bandwidth might be problematic due to the massive messages that are sent by the protocol.
The next step in comparing RESTful to SOAP is going to be learning about the difficulties associated with REST API.

Challenges in REST API

Inadequate Security REST does not impose any kind of security on its users, in contrast to SOAP. Because of this, REST is an excellent choice for publicly accessible URLs; nevertheless, when it comes to the transmission of private data between a client and a server, REST is the technique that should be avoided at all costs when developing web services.
Absence of state The vast majority of web applications call for some kind of stateful method. For instance, if you were using a shopping website that featured a built-in mechanism for storing products known as a shopping cart, you would need to be aware of the total quantity of items stored in the shopping cart before you could complete the purchase. The client, unfortunately, is the one who is responsible for maintaining this state, which only serves to make the client application more cumbersome and difficult to keep up to date.

Difference between SOAP Vs CORBA Vs DCOM Vs Java RMI

Prior to the development of SOAP and REST API, remote access strategies such as the RPC (remote procedure calls) approaches were already in widespread use. The following is an explanation of the many different methods of remote access that were available.

CORBA stands for “Common Object Request Broker Architecture,” which was its previous name. The purpose of putting in place this framework was to make sure that programmes developed for different platforms could communicate with one another. Although an object-oriented architecture was the foundation on which CORBA was built, it was not necessary for the application doing the calling to be based on the same architecture. The fact that it must be built in a distinct language known as the Interface Definition Language was by far the most significant drawback of utilising this method. As a result, developers were had to learn yet another language in order to make use of the CORBA system.
Distributed Component Object Model, or DCOM for short, is a Microsoft-exclusive technology that allows clients to access remote components. DCOM is also known as the Distributed Component Object Model. The fact that it was up to the client programme to free up resources when they were no longer needed was the most significant drawback of using this approach. Second, in order for the web service to comprehend the request that was submitted, it was the client’s responsibility to ensure that the request was “wrapped” or “marshalled” in the appropriate manner before it was delivered. In addition, if the client application was written in Java and it needed to work with DCOM (a technology developed by Microsoft), then additional coding was required. This was necessary to ensure that applications written in other programming languages could work with web services that were based on DCOM.
Java RMI, also known as Java Remote Method Invocation, was Java’s implementation of how remote objects may be accessed via remote procedure calls. It was also known by its full name, Java Remote Method Invocation. The fact that Java RMI could only be executed on a Java Virtual Machine constituted the most significant limitation of this technology. This indicated that the programme doing the calling must also be executed on the Java framework in order to make use of Java Remote Method Invocation (RMI).
The following is an explanation of the primary distinctions between SOAP and these other techniques:

Working over HTTP — Every one of the RPC techniques has a significant drawback, and that is the fact that they are unable to function through the HTTP protocol. The need that all apps on the web work on this protocol used to be a significant barrier for clients that needed to access RPC-style web services. This was because all programmes on the online had to work on this protocol.
Working with ports that are not standard Because RPC-style web services did not function properly when using the HTTP protocol, special ports had to be opened for them in order for clients to access the functionality that was provided by these web services.