By default, filters doesn’t support excluding a specific URL pattern, whenever you define a URL pattern for a filter then any request matching this pattern is handled by the filter without exceptions. The simplest way for excluding URLs from a filter is to map your filter to a very specific pattern.

Servlets and URL Paths xml defines mappings between URL paths and the servlets that handle requests with those paths. You can declare multiple servlets using the same class with different initialization parameters. The name for each servlet must be unique across the deployment descriptor.

Any word after the question mark (?) in a URL is considered to be a parameter which can hold values. The value for the corresponding parameter is given after the symbol “equals” (=). Multiple parameters can be passed through the URL by separating them with multiple “&”.

xml File. The web. xml file is the standard deployment descriptor for the Web application that the Web service is a part of. It declares the filters and servlets used by the service.

web. xml defines mappings between URL paths and the servlets that handle requests with those paths. The web server uses this configuration to identify the servlet to handle a given request and call the class method that corresponds to the request method.

Starting in Servlet 3, no web. xml is required. You’re going to want to use something like Tomcat 7 or 8 (better choice).

xml file? No, you don’t need, jsp file can be directly invoked by URL. If we create a servlet and used in html form action tag we create an entry in web.

If you have a legacy Spring MVC application, which still uses web. xml, you can remove the file if you’re on Servlet 3.0+. One option is to implement WebApplicationInitializer directly.

Application Configuration Spring MVC web applications use the web. xml file as a deployment descriptor file. This is no longer the case with Spring Boot. If we need a special filter, we can register it in a Java class configuration.

<init-param> and param> are static parameters which are stored in web. xml file. If you have any data which doesn’t change frequently you can store it in one of them. If you want to store particular data which is confined to a particular servlet scope, then you can use <init-param> .

Servlets as the Foundation of a Java Web Application Given the project is a simple Spring Boot application, you’ll be able to run it via the Spring5Application. Since Tomcat is a Servlet container, naturally every HTTP request sent to a Tomcat web server is processed by a Java servlet.

Difference between @RestController and @Controller in Spring. The @Controller is a common annotation which is used to mark a class as Spring MVC Controller while the @RestController is a special controller used in RESTFul web services and the equivalent of @Controller + @ResponseBody .

Spring RestController annotation is a convenience annotation that is itself annotated with @Controller and @ResponseBody . Spring RestController annotation is used to create RESTful web services using Spring MVC. Spring RestController takes care of mapping request data to the defined request handler method.

@RestController is not meant to be used to return views to be resolved. It is supposed to return data which will be written to the body of the response, hence the inclusion of @ResponseBody .

In this Spring MVC tutorial, you will learn how to read HTTP Request Header in the Rest Controller class of your Application….Reading HTTP Request Header

1. Accept HTTP GET Request,
2. Read an “Accept” HTTP Request Header,
3. Read an “Authorization” HTTP Request Header,
4. Return the values of both headers in HTTP Response body.

1) The @RequestParam is used to extract query parameters while @PathVariable is used to extract data right from the URI. Even though both are used to extract data from URL, @RequestParam is used to retrieve query parameters, anything after? in the URL, while @PathVariable is used to retrieve values from URI itself.

RestController is a Spring annotation that is used to build REST API in a declarative way. RestController annotation is applied to a class to mark it as a request handler, and Spring will do the building and provide the RESTful web service at runtime.

The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line. Use PUT when you want to modify a singular resource which is already a part of resources collection.