REST Web services have really come a long way since its inception. In 2002, the Web consortium had released the definition of WSDL and SOAP web services. This formed the standard of how web services are implemented.
REST is a way to access resources which lie in a particular environment. For example, you could have a server that could be hosting important documents or pictures or videos. All of these are an example of resources. If a client, say a web browser needs any of these resources, it has to send a request to the server to access these resources. Now REST services defines a way on how these resources can be accessed.@media(max-width: 499px) .videocontentmobile min-height: 280px; @media only screen and (min-width: 500px) and (max-width: 1023px).videocontentmobile min-height: 100px;@media(min-width: 1024px) .videocontentmobile min-height: 250px; if (typeof(pubwise) != 'undefined' && pubwise.enabled === true) pubwise.que.push(function() pubwise.renderAd('div-gpt-ad-9092914-1'); ); else googletag.cmd.push(function () googletag.display('div-gpt-ad-9092914-1'); googletag.pubads().refresh([gptadslots['div-gpt-ad-9092914-1']]); ); The key elements of a RESTful implementation are as follows:
JSON Web Services for Android.pdf
But in the end, no matter what the environment is, the end result should always be the same that they should be able to talk to each other. Restful web services offer this flexibility to applications built on various programming languages and platforms to talk to each other.
The REST architecture is based on a few characteristics which are elaborated below. Any RESTful web service has to comply with the below characteristics in order for it to be called RESTful. These characteristics are also known as design principles which need to be followed when working with RESTful based services.
In this RESTful API example, we are going to create our REST application in .Net using Visual Studio. In our example, for Restful web services we are going to emulate the following REST service example.
Step 4) Make a configuration.The next step is to actually make a configuration change to enable this project to complete work with RESTful web services. This requires to make a change to the file called Web.config. This file appears in the same window as the Webservice project file. The file Web.config contains all configurations that make the web application work as it should. The change being made actually allows the application to send and receive data as a pure RESTful web service.
RESTful APIs have also given birth to various trends like cloud computing and microservices-based architecture. They have made communication and computing over the internet seem easy. Hence, it is important for any developer to know what REST is, how it works, what are its features and how can you develop services in a secure manner to go with the trend. Many companies prefer developers with REST knowledge as they can help them develop products that are scalable, easy to maintain and make their products reach out to the world due to the power of the internet.
In the below section, we will see what are the most commonly asked questions on RESTful web services during an interview and some questions on the JAX-RS library, and some on RESTful web services implemented using the Spring MVC framework.
RESTful web services are services that follow REST architecture. REST stands for Representational State Transfer and uses HTTP protocol (web protocol) for implementation. These services are lightweight, provide maintainability, scalability, support communication among multiple applications that are developed using different programming languages. They provide means of accessing resources present at server required for the client via the web browser by means of request headers, request body, response body, status codes, etc.
As the name itself stands (JAX-RS= Java API for RESTful Web Services) is a Java-based specification defined by JEE for the implementation of RESTful services. The JAX-RS library makes usage of annotations from Java 5 onwards to simplify the process of web services development. The latest version is 3.0 which was released in June 2020. This specification also provides necessary support to create REST clients.
RESTful web services use REST API as means of implementation using the HTTP protocol. REST API is nothing but an application programming interface that follows REST architectural constraints such as statelessness, cacheability, maintainability, and scalability. It has become very popular among the developer community due to its simplicity. Hence, it is very important to develop safe and secure REST APIs that follow good conventions. Below are some best practices for developing REST APIs:
REST services follow the concept of statelessness which essentially means no storing of any data across the requests on the server. This makes it easier to scale horizontally because the servers need not communicate much with each other while serving requests.
REST services have gained popularity due to the nature of simplicity, scalability, faster speed, improved performance, and multiple data format support. But, SOAP has its own advantages too. Developers use SOAP where the services require advanced security and reliability.
Yes, we can. TLS does the task of encrypting the communication between the REST client and the server and provides the means to authenticate the server to the client. It is used for secure communication as it is the successor of the Secure Socket Layer (SSL). HTTPS works well with both TLS and SSL thereby making it effective while implementing RESTful web services. One point to mention here is, the REST inherits the property of the protocol it implements. So security measures are dependent on the protocol REST implements.
RESTful web services can be tested using various tools like Postman, Swagger, etc. Postman provides a lot of features like sending requests to endpoints and show the response which can be converted to JSON or XML and also provides features to inspect request parameters like headers, query parameters, and also the response headers. Swagger also provides similar features like Postman and it provides the facility of documentation of the endpoints too. We can also use tools like Jmeter for performance and load testing of APIs.
JAX-RS stands for Java API for RESTful Web services. They are nothing but a set of Java-based APIs that are provided in the Java EE which is useful in the implementation and development of RESTful web services.
The RestTemplate is the main class meant for the client-side access for Spring-based RESTful services. The communication to the server is accomplished using the REST constraints. This is similar to other template classes such as JdbcTemplate, HibernateTemplate, etc provided by Spring. The RestTemplate provides high-level implementation details for the HTTP Methods like GET, POST, PUT, etc, and gives the methods to communicate using the URI template, URI path params, request/response types, request object, etc as part of arguments.
Yes. Spring MVC needs to be on the classpath of the application while developing RESTful web services using Spring. This is because, the Spring MVC provides the necessary annotations like @RestController, @RequestBody, @PathVariable, etc. Hence the spring-mvc.jar needs to be on the classpath or the corresponding Maven entry in the pom.xml.
We have seen what are the most commonly asked questions on RESTful web services during an interview. REST APIs have become a very important tool in the software industry. Developing RESTful web services that are scalable and easily maintainable is considered an art. As the industry trends increase, the REST architecture would become more concrete and the demand for developers who know the development of RESTful web services would increase steadily.
Unless you are writing a Hello World Android application, chances are your application would need to connect to the outside world to fetch some data, such as live currency exchange rates, weather information, records from databases, etc. One of the easiest ways for your application to connect to the outside world is to use web services.
For the past few years, XML web services have dominated the arena for web services, as XML was touted as the ubiquitous medium for data exchange. However, using XML as the medium for your data payload suffers from the following problems:
In this article, you have seen how to consume a JSON service from within your Android application. You have seen two examples on how to parse a JSON string using the JSONObject and JSONArray classes available in the org.json package.
These methods test a couple of simple cases. The json() method hits the endpoint and the other asserts are pretty self explanatory. One detail about assertJson(): this method converts the response into an array searches for the argument, so the order is important. You can chain multiple assertJson() calls in that case.
APIs are broadly accepted and used in web applications. There are four different types of APIs commonly used in web services: public, partner, private and composite. In this context, the API "type" indicates the intended scope of use.
Partners have clear rights and licenses to access such APIs. For this reason, partner APIs generally incorporate stronger authentication, authorization and security mechanisms. Enterprises also typically do not monetize such APIs directly; partners are paid for their services rather than through API use.
APIs simplify design and development of new applications and services, and integration and management of existing ones. But they offer other significant benefits to developers and organizations at large. 2ff7e9595c
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