unit -4 spring web services like SOA Arch
- 1. Web services
- 3. SOA-Service Oriented Architecture SOA expands to Service Oriented Architecture, is a software model designed for achieving communication among distributed application components, irrespective of the differences in terms of technology, platform, etc.,
- 4. contd Service-Oriented Architecture (SOA) is a design approach and architectural style used in software development to create flexible and scalable systems by organizing software components (services) into loosely coupled, reusable, and interoperable units. These services can be thought of as self-contained, modular units that provide specific functionality and can communicate with each other over a network. Key concepts and principles of SOA include: • Services: These are the fundamental building blocks of an SOA. Services are self- contained, independent units of functionality that can be accessed over a network through standard protocols, such as HTTP, SOAP, or REST. Services are designed to perform specific tasks or functions and can be reused in different applications. • Loose Coupling: In SOA, services are loosely coupled, meaning they are independent of one another and can evolve separately without affecting other services. This allows for greater flexibility and adaptability in the system. • Interoperability: SOA promotes the use of standardized communication protocols and data formats to ensure that services can work together, regardless of the technologies or platforms on which they are implemented. This facilitates integration between heterogeneous systems.
- 6. What are Web services Web services are a technology that enables communication and data exchange between different software applications over the internet or a network. They provide a standardized way for applications, regardless of the programming languages, platforms, or technologies they are built with, to interact with one another. Web services are based on open standards and protocols, making them highly interoperable.
- 8. Types of Web Services There are mainly two types of web services. • Simple Object Access Protocol (SOAP) web services. • Representational State Transfer(REST) services.
- 9. SOAP • SOAP is an acronym for Simple Object Access Protocol. • SOAP is a XML-based protocol for accessing web services. • SOAP is a W3C recommendation for communication between applications.
- 10. • It is important for web applications to be able to communicate over the Internet. • The best way to communicate between applications is over HTTP, because HTTP is supported by all Internet browsers and servers. SOAP was created to accomplish this. • SOAP provides a way to communicate between applications running on different operating systems, with different technologies and programming languages.
- 11. SOAP Building Blocks A SOAP message is an ordinary XML document containing the following elements: • An Envelope element that identifies the XML document as a SOAP message • A Header element that contains header information • A Body element that contains call and response information • A Fault element containing errors and status information
- 13. SOAP Syntax
- 21. REST REST is an acronym that stands for REpresentational State Transfer. It was created by Roy Thomas Fielding, who also created HTTP. The primary purpose of RESTful web services is to improve the efficiency of online services. RESTful web services attempt to describe services by utilizing the many principles currently existing in HTTP. REST is a design approach, not a protocol.
- 26. contd • The standard message exchange format is not defined. REST services may be built using both XML and JSON. With REST, JSON is the more prevalent format. In REST, the key abstraction is a resource. Anything can be considered a resource. • The resource is available in XML, HTML, and JSON formats. A representational resource captures the current state. When we request a resource, we supply the resource's representation. HTTP's most significant methods are: • POST: This method generates a new resource. • DELETE: This command deletes the resource. • GET: This command reads a resource. • PUT: It is used to update an existing resource.
- 27. status codes • HTTP specifies the following standard status codes as well: • 401: UNAUTHORISED • 500: SERVER ERROR • 404: RESOURCE NOT FOUND • 200: SUCCESS • 201: CREATED
- 33. For example • If we conduct the following steps in the social media application, we will receive the following outcomes. • POST /users: This method creates a user. • GET /users/{id}: Retrieves information about a single user. • GET /users: It retrieves all users' information. • DELETE/users: It removes all users. • DELETE /users/{id}: This command deletes a user. • GET /users/{id}/posts/id post_id: It retrieves information about a certain post. • POST/users/{id}/ posts: This method produces a post for a certain user. • GET /users/{id}/post: Retrieve all posts for a certain user.