Clients can specify (using HTTP Accept header) the resource type they are interested in, and server may return the resource , specifying Content-Type of the resource it is serving. While doing that, Spring will [behind the scenes] use HTTP Message converters to convert the return value to HTTP response body [serialize the object to response body], based on Content-Type present in request HTTP header. Good thing about it is that you can control anything that goes into it. It comes with several constructors to carry the information you want to sent in HTTP Response.This Stack Overflow link is a must read to understand REST in detail. As already mentioned, in Spring 4, you may stop using this annotation. @Path Variable This annotation indicates that a method parameter should be bound to a URI template variable [the one in ''].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.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. The station is located at a distant of 5km west of New Delhi Railway Station.
Another area of local interest is the Chandni Chowk area that remains crowded most of the times.
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.
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.