Merge pull request #3922 from its-fpereira/BAEL-1505

BAEL-1505: Spring WebFlux Filters

spring-5-reactive/src/main/java/com/baeldung/reactive/controller/UserController.java

@@ -0,0 +1,15 @@
+package com.baeldung.reactive.controller;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+import reactor.core.publisher.Mono;
+
+@RestController
+public class UserController {
+
+    @GetMapping(path = "/users/{name}")
+    public Mono<String> getName(@PathVariable String name) {
+        return Mono.just(name);
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/reactive/filter/ExampleHandlerFilterFunction.java

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+package com.baeldung.reactive.filter;
+
+import org.springframework.web.reactive.function.server.HandlerFilterFunction;
+import org.springframework.web.reactive.function.server.HandlerFunction;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import static org.springframework.http.HttpStatus.FORBIDDEN;
+
+public class ExampleHandlerFilterFunction implements HandlerFilterFunction {
+
+    @Override
+    public Mono filter(ServerRequest serverRequest, HandlerFunction handlerFunction) {
+        if (serverRequest.pathVariable("name").equalsIgnoreCase("test")) {
+            return ServerResponse.status(FORBIDDEN).build();
+        }
+        return handlerFunction.handle(serverRequest);
+    }
+
+}
+

spring-5-reactive/src/main/java/com/baeldung/reactive/filter/ExampleWebFilter.java

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+package com.baeldung.reactive.filter;
+
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+
+@Component
+public class ExampleWebFilter implements WebFilter {
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange serverWebExchange, WebFilterChain webFilterChain) {
+        serverWebExchange.getResponse().getHeaders().add("web-filter", "web-filter-test");
+        return webFilterChain.filter(serverWebExchange);
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/reactive/handler/PlayerHandler.java

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+package com.baeldung.reactive.handler;
+
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+@Component
+public class PlayerHandler {
+
+    public Mono<ServerResponse> getName(ServerRequest request) {
+        Mono<String> name = Mono.just(request.pathVariable("name"));
+        return ok().body(name, String.class);
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/reactive/router/PlayerRouter.java

@@ -0,0 +1,22 @@
+package com.baeldung.reactive.router;
+
+import com.baeldung.reactive.filter.ExampleHandlerFilterFunction;
+import com.baeldung.reactive.handler.PlayerHandler;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+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 static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+
+@Configuration
+public class PlayerRouter {
+
+    @Bean
+    public RouterFunction<ServerResponse> route(PlayerHandler playerHandler) {
+        return RouterFunctions
+                .route(GET("/players/{name}"), playerHandler::getName)
+                .filter(new ExampleHandlerFilterFunction()::filter);
+    }
+}

spring-5-reactive/src/test/java/com/baeldung/reactive/controller/UserControllerTest.java

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+package com.baeldung.reactive.controller;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.EntityExchangeResult;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class UserControllerTest {
+
+    @Autowired
+    private WebTestClient webTestClient;
+
+    @Test
+    public void whenUserNameIsBaeldung_thenWebFilterIsApplied() {
+        EntityExchangeResult<String> result = webTestClient.get().uri("/users/baeldung")
+                .exchange()
+                .expectStatus().isOk()
+                .expectBody(String.class)
+                .returnResult();
+
+        assertEquals(result.getResponseBody(), "baeldung");
+        assertEquals(result.getResponseHeaders().getFirst("web-filter"), "web-filter-test");
+    }
+
+    @Test
+    public void whenUserNameIsTest_thenHandlerFilterFunctionIsNotApplied() {
+        webTestClient.get().uri("/users/test")
+                .exchange()
+                .expectStatus().isOk();
+    }
+}

spring-5-reactive/src/test/java/com/baeldung/reactive/handler/PlayerHandlerTest.java

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+package com.baeldung.reactive.handler;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.EntityExchangeResult;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class PlayerHandlerTest {
+
+    @Autowired
+    private WebTestClient webTestClient;
+
+    @Test
+    public void whenPlayerNameIsBaeldung_thenWebFilterIsApplied() {
+        EntityExchangeResult<String> result = webTestClient.get().uri("/players/baeldung")
+                .exchange()
+                .expectStatus().isOk()
+                .expectBody(String.class)
+                .returnResult();
+
+        assertEquals(result.getResponseBody(), "baeldung");
+        assertEquals(result.getResponseHeaders().getFirst("web-filter"), "web-filter-test");
+    }
+
+    @Test
+    public void whenPlayerNameIsTest_thenHandlerFilterFunctionIsApplied() {
+        webTestClient.get().uri("/players/test")
+                .exchange()
+                .expectStatus().isForbidden();
+    }
+
+}