[BAEL-11597] Move and update Etags article

* Moved etags article related code
* Fixed existing etag Ignored test
* Added etag scentsio adding etag support to a single endpoint
* Added tests for single endpoint etag scenario
* Cleaned now unused code in spring-rest-full module

spring-rest-full/src/main/java/org/baeldung/spring/Application.java

@@ -8,11 +8,9 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.boot.web.support.SpringBootServletInitializer;
-import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.web.context.request.RequestContextListener;
-import org.springframework.web.filter.ShallowEtagHeaderFilter;
 
 /**
  * Main Application Class - uses Spring Boot. Just run this as a normal Java
@@ -40,8 +38,4 @@ public class Application extends SpringBootServletInitializer {
         SpringApplication.run(Application.class, args);
     }
 
-    @Bean
-    public ShallowEtagHeaderFilter shallowEtagHeaderFilter() {
-        return new ShallowEtagHeaderFilter();
-    }
 }

spring-rest-full/src/main/java/org/baeldung/web/controller/FooController.java

@@ -6,10 +6,8 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.baeldung.persistence.model.Foo;
 import org.baeldung.persistence.service.IFooService;
-import org.baeldung.web.hateoas.event.ResourceCreatedEvent;
 import org.baeldung.web.util.RestPreconditions;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Controller;
@@ -26,9 +24,6 @@ import com.google.common.base.Preconditions;
 @RequestMapping(value = "/auth/foos")
 public class FooController {
 
-    @Autowired
-    private ApplicationEventPublisher eventPublisher;
-
     @Autowired
     private IFooService service;
 
@@ -71,9 +66,6 @@ public class FooController {
     public Foo create(@RequestBody final Foo resource, final HttpServletResponse response) {
         Preconditions.checkNotNull(resource);
         final Foo foo = service.create(resource);
-        final Long idOfCreatedResource = foo.getId();
-
-        eventPublisher.publishEvent(new ResourceCreatedEvent(this, response, idOfCreatedResource));
 
         return foo;
     }

spring-rest-full/src/main/java/org/baeldung/web/hateoas/event/ResourceCreatedEvent.java

@@ -1,28 +0,0 @@
-package org.baeldung.web.hateoas.event;
-
-import javax.servlet.http.HttpServletResponse;
-
-import org.springframework.context.ApplicationEvent;
-
-public class ResourceCreatedEvent extends ApplicationEvent {
-    private final HttpServletResponse response;
-    private final long idOfNewResource;
-
-    public ResourceCreatedEvent(final Object source, final HttpServletResponse response, final long idOfNewResource) {
-        super(source);
-
-        this.response = response;
-        this.idOfNewResource = idOfNewResource;
-    }
-
-    // API
-
-    public HttpServletResponse getResponse() {
-        return response;
-    }
-
-    public long getIdOfNewResource() {
-        return idOfNewResource;
-    }
-
-}

spring-rest-full/src/main/java/org/baeldung/web/hateoas/listener/ResourceCreatedDiscoverabilityListener.java

@@ -1,36 +0,0 @@
-package org.baeldung.web.hateoas.listener;
-
-import java.net.URI;
-
-import javax.servlet.http.HttpServletResponse;
-
-import org.apache.http.HttpHeaders;
-import org.baeldung.web.hateoas.event.ResourceCreatedEvent;
-import org.springframework.context.ApplicationListener;
-import org.springframework.stereotype.Component;
-import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
-
-import com.google.common.base.Preconditions;
-
-@Component
-class ResourceCreatedDiscoverabilityListener implements ApplicationListener<ResourceCreatedEvent> {
-
-    @Override
-    public void onApplicationEvent(final ResourceCreatedEvent resourceCreatedEvent) {
-        Preconditions.checkNotNull(resourceCreatedEvent);
-
-        final HttpServletResponse response = resourceCreatedEvent.getResponse();
-        final long idOfNewResource = resourceCreatedEvent.getIdOfNewResource();
-
-        addLinkHeaderOnResourceCreation(response, idOfNewResource);
-    }
-
-    void addLinkHeaderOnResourceCreation(final HttpServletResponse response, final long idOfNewResource) {
-        // final String requestUrl = request.getRequestURL().toString();
-        // final URI uri = new UriTemplate("{requestUrl}/{idOfNewResource}").expand(requestUrl, idOfNewResource);
-
-        final URI uri = ServletUriComponentsBuilder.fromCurrentRequestUri().path("/{idOfNewResource}").buildAndExpand(idOfNewResource).toUri();
-        response.setHeader(HttpHeaders.LOCATION, uri.toASCIIString());
-    }
-
-}

spring-rest-full/src/main/webapp/WEB-INF/web.xml

@@ -23,15 +23,6 @@
         <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
     </listener>
 
-    <filter>
-        <filter-name>etagFilter</filter-name>
-        <filter-class>org.springframework.web.filter.ShallowEtagHeaderFilter</filter-class>
-    </filter>
-    <filter-mapping>
-        <filter-name>etagFilter</filter-name>
-        <url-pattern>/*</url-pattern>
-    </filter-mapping>
-
     <!-- Spring child -->
     <servlet>
         <servlet-name>api</servlet-name>