BAEL-636: register servlet using java config (#1525)

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

@@ -0,0 +1,87 @@
+package com.baeldung.functional;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+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.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;
+
+@SpringBootApplication
+@ComponentScan(basePackages = { "com.baeldung.functional" })
+public class FunctionalSpringBootApplication {
+
+    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);
+          });
+    }
+
+    @Bean
+    public ServletRegistrationBean servletRegistrationBean() throws Exception {
+        HttpHandler httpHandler = WebHttpHandlerBuilder
+          .webHandler(toHttpHandler(routingFunction()))
+          .prependFilter(new IndexRewriteFilter())
+          .build();
+        ServletRegistrationBean registrationBean = new ServletRegistrationBean<>(new RootServlet(httpHandler), "/");
+        registrationBean.setLoadOnStartup(1);
+        registrationBean.setAsyncSupported(true);
+        return registrationBean;
+    }
+
+    @Configuration
+    @EnableWebSecurity
+    @Profile("!https")
+    static class SecurityConfig extends WebSecurityConfigurerAdapter {
+        @Override
+        protected void configure(final HttpSecurity http) throws Exception {
+            http
+              .authorizeRequests()
+              .anyRequest()
+              .permitAll();
+        }
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(FunctionalSpringBootApplication.class, args);
+    }
+
+}

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

@@ -33,7 +33,7 @@ public class RootServlet extends ServletHttpHandlerAdapter {
           .build());
     }
 
-    private RootServlet(HttpHandler httpHandler) {
+    RootServlet(HttpHandler httpHandler) {
         super(httpHandler);
     }