Add ETag info to CatalogService example

spring-cloud-open-service-broker-docs/src/test/java/com/example/servicebroker/ExampleCatalogService.java

@@ -6,6 +6,8 @@
 import org.springframework.cloud.servicebroker.model.catalog.Plan;
 import org.springframework.cloud.servicebroker.model.catalog.ServiceDefinition;
 import org.springframework.cloud.servicebroker.service.CatalogService;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -22,21 +24,41 @@ public Mono<Catalog> getCatalog() {
 	@Override
 	public Mono<ServiceDefinition> getServiceDefinition(String serviceId) {
 		return Mono.just(ServiceDefinition.builder()
-			.id(serviceId)
-			.name("example")
-			.description("A simple example")
-			.bindable(true)
-			.tags("example", "tags")
-			.plans(getPlan())
-			.build());
+				.id(serviceId)
+				.name("example")
+				.description("A simple example")
+				.bindable(true)
+				.tags("example", "tags")
+				.plans(getPlan())
+				.build());
+	}
+
+	@Override
+	public Mono<ResponseEntity<Catalog>> getResponseEntityCatalog(HttpHeaders httpHeaders) {
+		// Use this method to handle catalog caching and ETag support.
+		// The example below is a basic ETag comparison and response.
+		if ("useful-etag-value".equals(httpHeaders.getIfNoneMatch())) {
+			return Mono.just(ResponseEntity
+					.status(304)
+					.eTag("useful-etag-value")
+					.build());
+		}
+		else {
+			return getCatalog()
+					.map(catalog -> ResponseEntity
+							.status(200)
+							.eTag("different-etag-value")
+							.body(catalog));
+		}
 	}
 
 	private Plan getPlan() {
 		return Plan.builder()
-		   .id("simple-plan")
-		   .name("standard")
-		   .description("A simple plan")
-		   .free(true)
-		   .build();
+				.id("simple-plan")
+				.name("standard")
+				.description("A simple plan")
+				.free(true)
+				.build();
 	}
+
 }