Difference Between WADL and WSDL

WADL stands for Web Application Description Language which is a machine-readable language consisting of  XML descriptions, which is based on HTTP web services. WADL models resources provide services facilities and bonds between them. It is mainly intended to simplify the reuse of web services and the base relation between the platform and the one which uses HTTP architecture of the web. It promotes a self-dependent platform that concentrates on the reuse of applications beyond the basic use in a web browser. WADL was submitted to the WWW (World Wide Web) consortium on 31st august 2009 by the Sun microsystem with no standardized current plan.

Major element of WADL:  

• <grammars> specify W3C, XML schema in web services.
• <resource> specifies methods which supported for web services as URI templates
• <method> specifies request and response details for web services.
• <representation > describes the proper HTTP format, which refers to grammar.

Advantages of WADL:

• The purpose of WADL is to define a contract specific like REST services.
• SOAP was designed for a distributed computing environment whereas REST is designed for a point environment. WADL aims to simplify the reuse and integrate complex enterprise systems maintained by several different companies.

Disadvantages of WADL:

• SOAP was designed for a distributed computing environment whereas REST was designed from point to point environment and WADL can be used to define the interface for REST services.

WSDL stands for Web Services Description Language. It is an XML-based definition language mainly used for describing the functionality of SOAP-based web services. It contains a random number of services. A binding exposes an interface for the specified protocol. The WSDL content tab provides details on the WSDL file which are central to testing SOAP-based services. WSDL winds up as an undertaking between the provider and the consumer services. It was developed jointly by IBM and Microsoft and recommended to the web world on 26th June 2007.    

Major elements of WSDL:

• <types> defines data type which is used in XML schema web services.
• <message> defines data elements for each specific operation in web services.
• <port Type> operations and messages involved in different web pages and services they provide.
• <binding> defines protocol and data format based on port type in the web services.

Advantages of WSDL:

• WSDL works combinedly with SOAP and UDDI and also provides a systematic approach for defining web services.
• It is mainly used to reduce total LOC which is a must to access the web services and it can be updated dynamically which allows users to upgrade in new patterns.

Disadvantages of WSDL:

• Single-mode messaging is prohibited.
• It cannot include more than one file i.e. cannot have more than one <wsdl: include> element.
• It does not support output mapping.

Difference between WADL and WSDL:

S.NO.	WADL	WSDL
01.	Web Application Description Language.	Web Service Description Language.
02.	XML helps in describing restful web services.	XML helps in describing SOAP-based web series.
03.	A client loads a WADL file and accesses the complete functionality of the web services.	A client loads the WSDL file and gets into the method web services which call the arguments and returns data type.
04.	WADL is equivalent to SOAP’s web services description language.	WSDL is a machine-readable description with the current version of 2.0.
05.	It is lightweight, easy to understand and write as compared to WSDL.	Difficult to understand and write as compared to WADL.
06.	It does not evolve binding to SMTP servers. It has a simple design.	It consists of binding to STMP services. it consists of complex design.
07.	It requires some simple URI template mechanism. Also, limited scope compared to WSDL.	Whereas, here the users need to define the XML input message to use the URI template mechanism.  It has more range compared to WADL.
08.	W3C does not recommend the WADL interface. WADL is very simple.	But W3C does recommend a WSDL interface. whereas, it is more flexible than WADL.