Make ReactiveWebServerFactory functional interface

Update `ReactiveWebServerFactory` to contain only a single method.

Fixes gh-8559

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/webflux/MockReactiveWebServerFactory.java

@@ -41,12 +41,6 @@ public class MockReactiveWebServerFactory extends AbstractReactiveWebServerFacto
 		return this.webServer;
 	}
 
-	@Override
-	public WebServer getWebServer(Map<String, HttpHandler> handlerMap) {
-		this.webServer = spy(new MockReactiveWebServer(handlerMap, getPort()));
-		return this.webServer;
-	}
-
 	public MockReactiveWebServer getWebServer() {
 		return this.webServer;
 	}

spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyReactiveWebServerFactory.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.web.embedded.jetty;
 
 import java.net.InetSocketAddress;
-import java.util.Map;
 
 import org.eclipse.jetty.server.AbstractConnector;
 import org.eclipse.jetty.server.ConnectionFactory;
@@ -62,8 +61,8 @@ public class JettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 	}
 
 	/**
-	 * Create a new {@link JettyServletWebServerFactory} that listens for requests
-	 * using the specified port.
+	 * Create a new {@link JettyServletWebServerFactory} that listens for requests using
+	 * the specified port.
 	 * @param port the port to listen on
 	 */
 	public JettyReactiveWebServerFactory(int port) {
@@ -77,13 +76,6 @@ public class JettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 		return new JettyWebServer(server, getPort() >= 0);
 	}
 
-	@Override
-	public WebServer getWebServer(Map<String, HttpHandler> handlerMap) {
-		JettyHttpHandlerAdapter servlet = new JettyHttpHandlerAdapter(handlerMap);
-		Server server = createJettyServer(servlet);
-		return new JettyWebServer(server, getPort() >= 0);
-	}
-
 	protected Server createJettyServer(JettyHttpHandlerAdapter servlet) {
 		int port = (getPort() >= 0 ? getPort() : 0);
 		InetSocketAddress address = new InetSocketAddress(getAddress(), port);

spring-boot/src/main/java/org/springframework/boot/web/embedded/netty/NettyReactiveWebServerFactory.java

@@ -16,8 +16,6 @@
 
 package org.springframework.boot.web.embedded.netty;
 
-import java.util.Map;
-
 import reactor.ipc.netty.http.server.HttpServer;
 
 import org.springframework.boot.web.reactive.server.AbstractReactiveWebServerFactory;
@@ -49,14 +47,6 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 		return new NettyWebServer(server, handlerAdapter);
 	}
 
-	@Override
-	public WebServer getWebServer(Map<String, HttpHandler> handlerMap) {
-		HttpServer server = createHttpServer();
-		ReactorHttpHandlerAdapter handlerAdapter = new ReactorHttpHandlerAdapter(
-				handlerMap);
-		return new NettyWebServer(server, handlerAdapter);
-	}
-
 	private HttpServer createHttpServer() {
 		HttpServer server;
 		if (getAddress() != null) {

spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactory.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.web.embedded.tomcat;
 
 import java.io.File;
-import java.util.Map;
 
 import org.apache.catalina.Host;
 import org.apache.catalina.connector.Connector;
@@ -73,14 +72,6 @@ public class TomcatReactiveWebServerFactory extends AbstractReactiveWebServerFac
 		return new TomcatWebServer(tomcatServer, getPort() >= 0);
 	}
 
-	@Override
-	public WebServer getWebServer(Map<String, HttpHandler> handlerMap) {
-		Tomcat tomcatServer = createTomcatServer();
-		TomcatHttpHandlerAdapter servlet = new TomcatHttpHandlerAdapter(handlerMap);
-		prepareContext(tomcatServer.getHost(), servlet);
-		return new TomcatWebServer(tomcatServer, getPort() >= 0);
-	}
-
 	private Tomcat createTomcatServer() {
 		Tomcat tomcat = new Tomcat();
 		File baseDir = createTempDir("tomcat");

spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/UndertowReactiveWebServerFactory.java

@@ -16,8 +16,6 @@
 
 package org.springframework.boot.web.embedded.undertow;
 
-import java.util.Map;
-
 import io.undertow.Undertow;
 
 import org.springframework.boot.web.reactive.server.AbstractReactiveWebServerFactory;
@@ -65,14 +63,6 @@ public class UndertowReactiveWebServerFactory extends AbstractReactiveWebServerF
 		return new UndertowWebServer(builder, getPort() >= 0);
 	}
 
-	@Override
-	public WebServer getWebServer(Map<String, HttpHandler> handlerMap) {
-		Undertow.Builder builder = createBuilder(getPort());
-		UndertowHttpHandlerAdapter handler = new UndertowHttpHandlerAdapter(handlerMap);
-		builder.setHandler(handler);
-		return new UndertowWebServer(builder, getPort() >= 0);
-	}
-
 	private Undertow.Builder createBuilder(int port) {
 		Undertow.Builder builder = Undertow.builder();
 		if (this.bufferSize != null) {

spring-boot/src/main/java/org/springframework/boot/web/reactive/server/ReactiveWebServerFactory.java

@@ -16,8 +16,6 @@
 
 package org.springframework.boot.web.reactive.server;
 
-import java.util.Map;
-
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.http.server.reactive.HttpHandler;
 
@@ -28,6 +26,7 @@ import org.springframework.http.server.reactive.HttpHandler;
  * @since 2.0.0
  * @see WebServer
  */
+@FunctionalInterface
 public interface ReactiveWebServerFactory {
 
 	/**
@@ -41,12 +40,4 @@ public interface ReactiveWebServerFactory {
 	 */
 	WebServer getWebServer(HttpHandler httpHandler);
 
-	/**
-	 * Register a map of {@link HttpHandler}s, each to a specific context path.
-	 * @param handlerMap a map of context paths and the associated {@code HttpHandler}
-	 * @return a fully configured and started {@link WebServer}
-	 * @see WebServer#stop()
-	 */
-	WebServer getWebServer(Map<String, HttpHandler> handlerMap);
-
 }