Following is one possible Rest based controller, implementing REST API. Basically, @Rest Controller , @Request Body, Response Entity & @Path Variable are all you need to know to implement a REST API in Spring 4.
I said possible, means Other’s may implement it in another way, still (or even more pure way) conforming to REST style. Additionally, spring provides several support classes to help you implement something customized.
This is what our REST API does: package com.websystique.springmvc.controller; import Media Type : With @Request Mapping annotation, you can additionally, specify the Media Type to be produced or consumed (using produces or consumes attributes) by that particular controller method, to further narrow down the mapping. You might be wondering how the response is sent as JSON string, and the Content-Type header in response confirms that. This is due to the fact that we have included Jackson library in our project.
List; import org.springframework.beans.factory.annotation. At the at end of day, it’s just a plain controller class, part of a deploy-able application.[Complete downloadable application code is shown further down in post which you can deploy straight-away in your container]. Retrieve all users Open POSTMAN tool, select request type [GET for this usecase], specify the operation uri. Since spring finds this library in class path, it invokes inbuilt Mapping Jackson2Http Message Converter converter to convert the response (List of objects) into JSON.
In this post we will write a CRUD Restful Web Service using Spring MVC 4, and write a REST client with Rest Template to consume those services. It’s an is an architectural style which can be used to design web services, that can be consumed from a variety of clients. Under the hood, @Rest Controller is itself annotated with @Response Body, and can be considered as combination of @Controller and @Response Body.
We will also test those services using external clients. The core idea is that, rather than using complex mechanisms such as CORBA, RPC or SOAP to connect between machines, simple HTTP is used to make calls among them. @Request Body : If a method parameter is annotated with @Request Body, Spring will bind the incoming HTTP request body(for the URL mentioned in @Request Mapping for that method) to that parameter.
For instance, if we want to serve XML as well, we should annotate User class with proper JAXB annoations. Retrieve Single User Specify a GET with /user/1 , click on send.
Now try to send a GET with invalid identifier, you should receive a HTTP 404. Create a User Select the method as POST, specify uri as /user/, specify body in POSTMAN body tab, select the type [application/json]. Update a User Send a HTTP PUT request to update a user. Notice that we have received response body this time. Verify users after delete-all Postman tool we used above is a wonderful Client to test Rest API.
A survey research method was administered by using a peer-reviewed and pilot-tested questionnaire.Data were collected from librarians and LIS school academicians working at Bahauddin Zakariya University of Multan and the Islamia University of Bahawalpur.Findings showed that respondent's attitude was positive; majority agreed that the use of social media is important to capture the attention of online users and helps in distance learning and knowledge sharing.But you should find a Location header specifying the . HTTP Methods and corresponding Rest Template methods: package com.websystique.springmvc; import Origin ‘ is therefore not allowed access.” OR ” XMLHttp Request cannot load After all, we are here to learn together, aren’t we?Origin is not allowed by Access-Control-Allow-Origin.” are common in such case. Basically, on server side, we can return additional CORS access control headers with response, which will eventually allow further inter-domain communication. Remember : Accept header says about what type client can understand. But the details to access REST services using this are too low level. Rest Template provides higher level methods that correspond to each of the six main HTTP methods that make invoking many RESTful services a one-liner and enforce REST best practices. Rest Template; import com.websystique.springmvc.model. User; public class Spring Rest Test Client Testing list All Users API----------- User : id=1, Name=Sam, Age=30, Salary=70000.0 User : id=2, Name=Tom, Age=40, Salary=50000.0 User : id=3, Name=Jerome, Age=45, Salary=30000.0 User : id=4, Name=Silvia, Age=50, Salary=40000.0 Testing get User API---------- User [id=1, name=Sam, age=30, salary=70000.0] Testing create User API---------- Location : Service/user/5 Testing list All Users API----------- User : id=1, Name=Sam, Age=30, Salary=70000.0 User : id=2, Name=Tom, Age=40, Salary=50000.0 User : id=3, Name=Jerome, Age=45, Salary=30000.0 User : id=4, Name=Silvia, Age=50, Salary=40000.0 User : id=5, Name=Sarah, Age=51, Salary=134.0 Testing update User API---------- User [id=1, name=Tomy, age=33, salary=70000.0] Testing list All Users API----------- User : id=1, Name=Tomy, Age=33, Salary=70000.0 User : id=2, Name=Tom, Age=40, Salary=50000.0 User : id=3, Name=Jerome, Age=45, Salary=30000.0 User : id=4, Name=Silvia, Age=50, Salary=40000.0 User : id=5, Name=Sarah, Age=51, Salary=134.0 Testing delete User API---------- Testing list All Users API----------- User : id=1, Name=Tomy, Age=33, Salary=70000.0 User : id=2, Name=Tom, Age=40, Salary=50000.0 User : id=4, Name=Silvia, Age=50, Salary=40000.0 User : id=5, Name=Sarah, Age=51, Salary=134.0 Testing all delete Users API---------- Testing list All Users API----------- No user exist---------- package com.websystique.springmvc.service; import Abstract Annotation Config Dispatcher Servlet Initializer; public class Hello World Initializer extends Abstract Annotation Config Dispatcher Servlet Initializer While accessing the REST API, you might face issues concerning Same Origin Policy. If you appreciate the effort I have put in this learning site, help me improve the visibility of this site towards global audience by sharing and linking this site from within and beyond your network.Content-Type header says what type of data actually is of. You should see HTTP 200 response with no body (as API don’t send anything in body). But no one stops you if you do want to send the content in Response body of a POST/PUT request. Below shown are HTTP methods and corresponding Rest Template methods to handle that type of HTTP request. Errors like : ” No ‘Access-Control-Allow-Origin’ header is present on the requested resource. You & your friends can always link my site from your site on and share the learning.With Spring, we can write a simple filter which adds those CORS specific headers in each response. package com.websystique.springmvc.configuration; import The Department of Lifelong Learning and Extension [DLLE] (known earlier as Department of Adult and Continuing Education and Extension) established on October 12, in the Year 1978 and has been recognized as a statutory Department of the University of Mumbai since 1994 to promote a meaningful and sustained rapport between the Universities and the community.The DLLE offers flexible Continuing Education opportunities for the people.They demanded for trainings for social media usage and suggested that libraries should develop social media page for maximum exploitation of library services.Study recommends that libraries should develop their marketing plan for utilizing social media for news and service alerts and quick updates to online users and fund raising.In Rest based design, resources are being manipulated using a common set of verbs. While doing that, Spring will [behind the scenes] use HTTP Message converters to convert the HTTP request body into domain object [deserialize request body to domain object], based on ACCEPT or Content-Type header present in request.