#BAEL-636

spring-5/pom.xml

@@ -35,6 +35,17 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+
+        <!-- a fix for spring-boot dependency on Reactor -->
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-core</artifactId>
+            <version>3.0.6.BUILD-SNAPSHOT</version>
+        </dependency>
 
         <!-- utils -->
         <dependency>

spring-5/src/main/java/com/baeldung/functional/Actor.java

@@ -0,0 +1,23 @@
+package com.baeldung.functional;
+
+class Actor {
+    private String firstname;
+    private String lastname;
+
+    public Actor() {
+    }
+
+    public Actor(String firstname, String lastname) {
+        this.firstname = firstname;
+        this.lastname = lastname;
+    }
+
+    public String getFirstname() {
+        return firstname;
+    }
+
+    public String getLastname() {
+        return lastname;
+    }
+
+}

spring-5/src/main/java/com/baeldung/functional/FormHandler.java

@@ -0,0 +1,50 @@
+package com.baeldung.functional;
+
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
+import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+public class FormHandler {
+
+    Mono<ServerResponse> handleLogin(ServerRequest request) {
+        return request
+          .body(toFormData())
+          .map(MultiValueMap::toSingleValueMap)
+          .map(formData -> {
+              System.out.println("form data: " + formData.toString());
+              if ("baeldung".equals(formData.get("user")) && "you_know_what_to_do".equals(formData.get("token"))) {
+                  return ok()
+                    .body(Mono.just("welcome back!"), String.class)
+                    .block();
+              }
+              return ServerResponse
+                .badRequest()
+                .build()
+                .block();
+          });
+    }
+
+    Mono<ServerResponse> handleUpload(ServerRequest request) {
+        return request
+          .body(toDataBuffers())
+          .collectList()
+          .map(dataBuffers -> {
+              AtomicLong atomicLong = new AtomicLong(0);
+              dataBuffers.forEach(d -> atomicLong.addAndGet(d
+                .asByteBuffer()
+                .array().length));
+              System.out.println("data length:" + atomicLong.get());
+              return ok()
+                .body(fromObject(atomicLong.toString()))
+                .block();
+          });
+    }
+}

spring-5/src/main/java/com/baeldung/functional/FunctionalWebApplication.java

@@ -0,0 +1,80 @@
+package com.baeldung.functional;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.startup.Tomcat;
+import org.springframework.boot.web.embedded.tomcat.TomcatWebServer;
+import org.springframework.boot.web.server.WebServer;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
+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 org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+import reactor.core.publisher.Flux;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.*;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+public class FunctionalWebApplication {
+
+    private static final Actor BRAD_PITT = new Actor("Brad", "Pitt");
+    private static final Actor TOM_HANKS = new Actor("Tom", "Hanks");
+    private static final List<Actor> actors = new CopyOnWriteArrayList<>(Arrays.asList(BRAD_PITT, TOM_HANKS));
+
+    private RouterFunction<ServerResponse> routingFunction() {
+        FormHandler formHandler = new FormHandler();
+
+        RouterFunction<ServerResponse> restfulRouter = route(GET("/"), serverRequest -> ok().body(Flux.fromIterable(actors), Actor.class)).andRoute(POST("/"), serverRequest -> serverRequest
+          .bodyToMono(Actor.class)
+          .doOnNext(actors::add)
+          .then(ok().build()));
+
+        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld")))
+          .andRoute(POST("/login"), formHandler::handleLogin)
+          .andRoute(POST("/upload"), formHandler::handleUpload)
+          .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
+          .andNest(path("/actor"), restfulRouter)
+          .filter((request, next) -> {
+              System.out.println("Before handler invocation: " + request.path());
+              return next.handle(request);
+          });
+    }
+
+    WebServer start() throws Exception {
+        WebHandler webHandler = toHttpHandler(routingFunction());
+        HttpHandler httpHandler = WebHttpHandlerBuilder
+          .webHandler(webHandler)
+          .prependFilter(new IndexRewriteFilter())
+          .build();
+
+        Tomcat tomcat = new Tomcat();
+        tomcat.setHostname("localhost");
+        tomcat.setPort(9090);
+        Context rootContext = tomcat.addContext("", System.getProperty("java.io.tmpdir"));
+        ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(httpHandler);
+        Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        rootContext.addServletMappingDecoded("/", "httpHandlerServlet");
+
+        TomcatWebServer server = new TomcatWebServer(tomcat);
+        server.start();
+        return server;
+
+    }
+
+    public static void main(String[] args) {
+        try {
+            new FunctionalWebApplication().start();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}

spring-5/src/main/java/com/baeldung/functional/IndexRewriteFilter.java

@@ -0,0 +1,29 @@
+package com.baeldung.functional;
+
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+
+class IndexRewriteFilter implements WebFilter {
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange serverWebExchange, WebFilterChain webFilterChain) {
+        ServerHttpRequest request = serverWebExchange.getRequest();
+        if (request
+          .getURI()
+          .getPath()
+          .equals("/")) {
+            return webFilterChain.filter(serverWebExchange
+              .mutate()
+              .request(builder -> builder
+                .method(request.getMethod())
+                .contextPath(request.getContextPath())
+                .path("/test"))
+              .build());
+        }
+        return webFilterChain.filter(serverWebExchange);
+    }
+
+}

spring-5/src/main/resources/files/hello.txt

@@ -0,0 +1 @@
+hello

spring-5/src/test/java/com/baeldung/functional/FunctionalWebApplicationIntegrationTest.java

@@ -0,0 +1,154 @@
+package com.baeldung.functional;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.springframework.boot.web.server.WebServer;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.BodyInserters;
+
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromResource;
+
+public class FunctionalWebApplicationIntegrationTest {
+
+    private static WebTestClient client;
+    private static WebServer server;
+
+    @BeforeClass
+    public static void setup() throws Exception {
+        server = new FunctionalWebApplication().start();
+        client = WebTestClient
+          .bindToServer()
+          .baseUrl("http://localhost:" + server.getPort())
+          .build();
+    }
+
+    @AfterClass
+    public static void destroy() {
+        server.stop();
+    }
+
+    @Test
+    public void givenRouter_whenGetTest_thenGotHelloWorld() throws Exception {
+        client
+          .get()
+          .uri("/test")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBody(String.class)
+          .value()
+          .isEqualTo("helloworld");
+    }
+
+    @Test
+    public void givenIndexFilter_whenRequestRoot_thenRewrittenToTest() throws Exception {
+        client
+          .get()
+          .uri("/")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBody(String.class)
+          .value()
+          .isEqualTo("helloworld");
+    }
+
+    @Test
+    public void givenLoginForm_whenPostValidToken_thenSuccess() throws Exception {
+        MultiValueMap<String, String> formData = new LinkedMultiValueMap<>(1);
+        formData.add("user", "baeldung");
+        formData.add("token", "you_know_what_to_do");
+
+        client
+          .post()
+          .uri("/login")
+          .contentType(MediaType.APPLICATION_FORM_URLENCODED)
+          .exchange(BodyInserters.fromFormData(formData))
+          .expectStatus()
+          .isOk()
+          .expectBody(String.class)
+          .value()
+          .isEqualTo("welcome back!");
+    }
+
+    @Test
+    public void givenLoginForm_whenRequestWithInvalidToken_thenFail() throws Exception {
+        MultiValueMap<String, String> formData = new LinkedMultiValueMap<>(2);
+        formData.add("user", "baeldung");
+        formData.add("token", "try_again");
+
+        client
+          .post()
+          .uri("/login")
+          .contentType(MediaType.APPLICATION_FORM_URLENCODED)
+          .exchange(BodyInserters.fromFormData(formData))
+          .expectStatus()
+          .isBadRequest();
+    }
+
+    @Test
+    public void givenUploadForm_whenRequestWithMultipartData_thenSuccess() throws Exception {
+        Resource resource = new ClassPathResource("/baeldung-weekly.png");
+        client
+          .post()
+          .uri("/upload")
+          .contentType(MediaType.MULTIPART_FORM_DATA)
+          .exchange(fromResource(resource))
+          .expectStatus()
+          .isOk()
+          .expectBody(String.class)
+          .value()
+          .isEqualTo(String.valueOf(resource.contentLength()));
+    }
+
+    @Test
+    public void givenActors_whenAddActor_thenAdded() throws Exception {
+        client
+          .get()
+          .uri("/actor")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBody(Actor.class)
+          .list()
+          .hasSize(2);
+
+        client
+          .post()
+          .uri("/actor")
+          .exchange(fromObject(new Actor("Clint", "Eastwood")))
+          .expectStatus()
+          .isOk();
+
+        client
+          .get()
+          .uri("/actor")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBody(Actor.class)
+          .list()
+          .hasSize(3);
+    }
+
+    @Test
+    public void givenResources_whenAccess_thenGot() throws Exception {
+        client
+          .get()
+          .uri("/files/hello.txt")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBody(String.class)
+          .value()
+          .isEqualTo("hello");
+    }
+
+}