BAEL-878 [2] (#2194)

* code snippets for the `Java 9 Stream API improvements` article

* code snippets for the `Java 9 Stream API improvements` article [2 attempt]

* removed the first attempt

* the Spring 5 WebClient

* delted stream features test

* HttpMediaTypeNotAcceptableExceptionExampleController [0]

* reactive web client service was removed

* new WebClient

* new WebClient [2]

spring-5/pom.xml

@@ -39,6 +39,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-webflux</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.projectreactor</groupId>
+            <artifactId>reactor-spring</artifactId>
+            <version>1.0.1.RELEASE</version>
+        </dependency>
 
         <!-- utils -->
         <dependency>

spring-5/src/main/java/com/baeldung/web/reactive/client/WebClientController.java

@@ -0,0 +1,86 @@
+package com.baeldung.web.reactive.client;
+
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import org.springframework.http.*;
+import org.springframework.http.client.reactive.ClientHttpRequest;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.net.URI;
+import java.nio.charset.Charset;
+import java.time.ZonedDateTime;
+import java.util.Collections;
+
+@RestController
+public class WebClientController {
+
+    @ResponseStatus(HttpStatus.OK)
+    @GetMapping("/resource")
+    public void getResource() {
+    }
+
+    public void demonstrateWebClient() {
+        // request
+        WebClient.UriSpec<WebClient.RequestBodySpec> request1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST);
+        WebClient.UriSpec<WebClient.RequestBodySpec> request2 = createWebClientWithServerURLAndDefaultValues().post();
+
+        // request body specifications
+        WebClient.RequestBodySpec uri1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST).uri("/resource");
+        WebClient.RequestBodySpec uri2 = createWebClientWithServerURLAndDefaultValues().post().uri(URI.create("/resource"));
+
+        // request header specification
+        WebClient.RequestHeadersSpec<?> requestSpec1 = uri1.body(BodyInserters.fromPublisher(Mono.just("data"), String.class));
+        WebClient.RequestHeadersSpec<?> requestSpec2 = uri2.body(BodyInserters.fromObject("data"));
+
+        // inserters
+        BodyInserter<Publisher<String>, ReactiveHttpOutputMessage> inserter1 = BodyInserters
+                .fromPublisher(Subscriber::onComplete, String.class);
+
+
+        LinkedMultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("key1", "value1");
+        map.add("key2", "value2");
+
+        BodyInserter<MultiValueMap<String, ?>, ClientHttpRequest> inserter2 = BodyInserters.fromMultipartData(map);
+        BodyInserter<String, ReactiveHttpOutputMessage> inserter3 = BodyInserters.fromObject("body");
+
+        // responses
+        WebClient.ResponseSpec response1 = uri1
+                .body(inserter3)
+                .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+                .accept(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML)
+                .acceptCharset(Charset.forName("UTF-8"))
+                .ifNoneMatch("*")
+                .ifModifiedSince(ZonedDateTime.now())
+                .retrieve();
+        WebClient.ResponseSpec response2 = requestSpec2.retrieve();
+
+    }
+
+    private WebClient createWebClient() {
+        return WebClient.create();
+    }
+
+    private WebClient createWebClientWithServerURL() {
+        return WebClient.create("http://localhost:8081");
+    }
+
+    private WebClient createWebClientWithServerURLAndDefaultValues() {
+        return WebClient
+                .builder()
+                .baseUrl("http://localhost:8081")
+                .defaultCookie("cookieKey", "cookieValue")
+                .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+                .defaultUriVariables(Collections.singletonMap("url", "http://localhost:8080"))
+                .build();
+    }
+
+}

spring-5/src/test/java/com/baeldung/web/client/WebTestClientTest.java

@@ -0,0 +1,58 @@
+package com.baeldung.web.client;
+
+import com.baeldung.Spring5Application;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.web.reactive.function.server.RequestPredicates;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.server.WebHandler;
+import reactor.core.publisher.Mono;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = Spring5Application.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class WebTestClientTest {
+
+    @LocalServerPort
+    private int port;
+
+    private final RouterFunction ROUTER_FUNCTION = RouterFunctions.route(
+            RequestPredicates.GET("/resource"),
+            request -> ServerResponse.ok().build()
+    );
+    private final WebHandler WEB_HANDLER = exchange -> Mono.empty();
+
+    @Test
+    public void testWebTestClientWithServerWebHandler() {
+        WebTestClient.bindToWebHandler(WEB_HANDLER).build();
+    }
+
+    @Test
+    public void testWebTestClientWithRouterFunction() {
+        WebTestClient
+                .bindToRouterFunction(ROUTER_FUNCTION)
+                .build().get().uri("/resource")
+                .exchange()
+                .expectStatus().isOk()
+                .expectBody().isEmpty();
+    }
+
+    @Test
+    public void testWebTestClientWithServerURL() {
+        WebTestClient
+                .bindToServer()
+                .baseUrl("http://localhost:" + port)
+                .build()
+                .get()
+                .uri("/resource")
+                .exchange()
+                .expectStatus().is4xxClientError()
+                .expectBody();
+    }
+
+}