Extract CompositeHttpHandler functionality

Extract CompositeHttpHandler to a package private class and add direct
support via `HttpHandler.of(...)`. This removes the need for the
`HttpHandlerAdapterSupport` class.

spring-web/src/test/java/org/springframework/http/server/reactive/HttpHandlerTests.java

@@ -34,11 +34,11 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 /**
- * Unit tests for {@link HttpHandlerAdapterSupport}.
+ * Unit tests for {@link HttpHandler}.
  *
  * @author Rossen Stoyanchev
  */
-public class HttpHandlerAdapterSupportTests {
+public class HttpHandlerTests {
 
 	@Test
 	public void invalidContextPath() {
@@ -139,10 +139,14 @@ public class HttpHandlerAdapterSupportTests {
 
 
 	@SuppressWarnings("WeakerAccess")
-	private static class TestHttpHandlerAdapter extends HttpHandlerAdapterSupport {
+	private static class TestHttpHandlerAdapter {
+
+
+		private final HttpHandler httpHandler;
+
 
 		public TestHttpHandlerAdapter(Map<String, HttpHandler> handlerMap) {
-			super(handlerMap);
+			this.httpHandler = HttpHandler.of(handlerMap);
 		}
 
 		public ServerHttpResponse handle(String path) {
@@ -152,7 +156,7 @@ public class HttpHandlerAdapterSupportTests {
 
 		public ServerHttpResponse handle(ServerHttpRequest request) {
 			ServerHttpResponse response = new MockServerHttpResponse();
-			getHttpHandler().handle(request, response);
+			this.httpHandler.handle(request, response);
 			return response;
 		}
 	}

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/JettyHttpServer.java

@@ -20,7 +20,7 @@ import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
-
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.JettyHttpHandlerAdapter;
 import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
 
@@ -53,8 +53,8 @@ public class JettyHttpServer extends AbstractHttpServer {
 	}
 
 	private ServletHttpHandlerAdapter createServletAdapter() {
-		return getHttpHandlerMap() != null ? new JettyHttpHandlerAdapter(getHttpHandlerMap()) :
-				new JettyHttpHandlerAdapter(getHttpHandler());
+		return new JettyHttpHandlerAdapter(getHttpHandlerMap() != null
+				? HttpHandler.of(getHttpHandlerMap()) : getHttpHandler());
 	}
 
 	@Override

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/ReactorHttpServer.java

@@ -21,6 +21,7 @@ import java.util.concurrent.atomic.AtomicReference;
 import reactor.core.Loopback;
 import reactor.ipc.netty.NettyContext;
 
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
 
 /**
@@ -42,9 +43,8 @@ public class ReactorHttpServer extends AbstractHttpServer implements Loopback {
 	}
 
 	private ReactorHttpHandlerAdapter createHttpHandlerAdapter() {
-		return (getHttpHandlerMap() != null ?
-				new ReactorHttpHandlerAdapter(getHttpHandlerMap()) :
-				new ReactorHttpHandlerAdapter(getHttpHandler()));
+		return new ReactorHttpHandlerAdapter(getHttpHandlerMap() != null
+				? HttpHandler.of(getHttpHandlerMap()) : getHttpHandler());
 	}
 
 	@Override

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/RxNettyHttpServer.java

@@ -18,6 +18,7 @@ package org.springframework.http.server.reactive.bootstrap;
 
 import io.netty.buffer.ByteBuf;
 
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.RxNettyHttpHandlerAdapter;
 
 /**
@@ -37,9 +38,8 @@ public class RxNettyHttpServer extends AbstractHttpServer {
 	}
 
 	private RxNettyHttpHandlerAdapter createHttpHandlerAdapter() {
-		return (getHttpHandlerMap() != null ?
-				new RxNettyHttpHandlerAdapter(getHttpHandlerMap()) :
-				new RxNettyHttpHandlerAdapter(getHttpHandler()));
+		return new RxNettyHttpHandlerAdapter(getHttpHandlerMap() != null
+				? HttpHandler.of(getHttpHandlerMap()) : getHttpHandler());
 	}
 
 

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/TomcatHttpServer.java

@@ -21,7 +21,7 @@ import java.io.File;
 import org.apache.catalina.Context;
 import org.apache.catalina.LifecycleException;
 import org.apache.catalina.startup.Tomcat;
-
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
 import org.springframework.http.server.reactive.TomcatHttpHandlerAdapter;
 import org.springframework.util.Assert;
@@ -68,9 +68,8 @@ public class TomcatHttpServer extends AbstractHttpServer {
 	}
 
 	private ServletHttpHandlerAdapter initServletAdapter() {
-		return getHttpHandlerMap() != null ?
-				new TomcatHttpHandlerAdapter(getHttpHandlerMap()) :
-				new TomcatHttpHandlerAdapter(getHttpHandler());
+		return new TomcatHttpHandlerAdapter(getHttpHandlerMap() != null
+				? HttpHandler.of(getHttpHandlerMap()) : getHttpHandler());
 	}
 
 

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/UndertowHttpServer.java

@@ -20,6 +20,7 @@ import java.net.InetSocketAddress;
 
 import io.undertow.Undertow;
 
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.UndertowHttpHandlerAdapter;
 
 /**
@@ -38,9 +39,8 @@ public class UndertowHttpServer extends AbstractHttpServer {
 	}
 
 	private UndertowHttpHandlerAdapter initHttpHandlerAdapter() {
-		return getHttpHandlerMap() != null ?
-				new UndertowHttpHandlerAdapter(getHttpHandlerMap()) :
-				new UndertowHttpHandlerAdapter(getHttpHandler());
+		return new UndertowHttpHandlerAdapter(getHttpHandlerMap() != null
+				? HttpHandler.of(getHttpHandlerMap()) : getHttpHandler());
 	}
 
 	@Override