Refine web.server package structure

Introduce adapter and handler sub-packages under web.server following a
review prompted by the addition of the session package and the package
cycle it brought in based on dependency on session.WebSessionManager.

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

@@ -18,6 +18,9 @@ package org.springframework.web.server;
 
 import reactor.core.publisher.Mono;
 
+import org.springframework.web.server.adapter.WebToHttpHandlerAdapter;
+import org.springframework.web.server.adapter.WebToHttpHandlerBuilder;
+
 /**
  * Contract to handle a web server exchange.
  *

spring-web-reactive/src/main/java/org/springframework/web/server/adapter/DefaultWebServerExchange.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.adapter;
 
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -25,6 +25,8 @@ import reactor.core.publisher.Processors;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.util.Assert;
+import org.springframework.web.server.WebServerExchange;
+import org.springframework.web.server.WebSession;
 import org.springframework.web.server.session.WebSessionManager;
 
 /**

spring-web-reactive/src/main/java/org/springframework/web/server/adapter/WebToHttpHandlerAdapter.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.adapter;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -24,6 +24,9 @@ import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.util.Assert;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.handler.WebHandlerDecorator;
+import org.springframework.web.server.WebServerExchange;
 import org.springframework.web.server.session.DefaultWebSessionManager;
 import org.springframework.web.server.session.WebSessionManager;
 

spring-web-reactive/src/main/java/org/springframework/web/server/adapter/WebToHttpHandlerBuilder.java

@@ -13,14 +13,20 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.adapter;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
+import org.springframework.web.server.WebExceptionHandler;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.handler.ExceptionHandlingWebHandler;
+import org.springframework.web.server.handler.FilteringWebHandler;
 import org.springframework.web.server.session.WebSessionManager;
 
 /**
@@ -76,7 +82,7 @@ public class WebToHttpHandlerBuilder {
 		return this;
 	}
 
-	public WebToHttpHandlerAdapter build() {
+	public HttpHandler build() {
 		WebHandler handler = this.targetHandler;
 		if (!this.exceptionHandlers.isEmpty()) {
 			WebExceptionHandler[] array = new WebExceptionHandler[this.exceptionHandlers.size()];

spring-web-reactive/src/main/java/org/springframework/web/server/adapter/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Implementation support to adapt
+ * {@link org.springframework.web.server Spring web server} to the underlying
+ * {@link org.springframework.http.server.reactive HTTP server} layer.
+ */
+package org.springframework.web.server.adapter;

spring-web-reactive/src/main/java/org/springframework/web/server/handler/ExceptionHandlingWebHandler.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.handler;
 
 import java.util.Arrays;
 import java.util.Collections;
@@ -24,6 +24,9 @@ import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
 import org.springframework.http.HttpStatus;
+import org.springframework.web.server.WebExceptionHandler;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.WebServerExchange;
 
 /**
  * {@code WebHandler} that decorates another with exception handling using one

spring-web-reactive/src/main/java/org/springframework/web/server/handler/FilteringWebHandler.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.handler;
 
 import java.util.Arrays;
 import java.util.Collections;
@@ -21,6 +21,11 @@ import java.util.List;
 
 import reactor.core.publisher.Mono;
 
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.WebServerExchange;
+
 /**
  * {@code WebHandler} that decorates another with a chain of {@link WebFilter}s.
  *

spring-web-reactive/src/main/java/org/springframework/web/server/handler/WebHandlerDecorator.java

@@ -13,11 +13,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.handler;
 
 import reactor.core.publisher.Mono;
 
 import org.springframework.util.Assert;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.WebServerExchange;
 
 /**
  * Base class for a {@link WebHandler} that decorates and delegates to another.

spring-web-reactive/src/main/java/org/springframework/web/server/handler/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Provides WebHandler implementations.
+ */
+package org.springframework.web.server.handler;

spring-web-reactive/src/main/java/org/springframework/web/server/package-info.java

@@ -15,6 +15,6 @@
  */
 
 /**
- * Web server infrastructure like filter, exchange (request + response), etc.
+ * Foundational Spring web server support.
  */
 package org.springframework.web.server;

spring-web-reactive/src/main/java/org/springframework/web/server/session/package-info.java

@@ -1,4 +1,4 @@
 /**
- * Support for a user session.
+ * Web session support.
  */
 package org.springframework.web.server.session;

spring-web-reactive/src/test/java/org/springframework/web/reactive/DispatcherHandlerErrorTests.java

@@ -49,9 +49,9 @@ import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.reactive.method.annotation.RequestMappingHandlerAdapter;
 import org.springframework.web.reactive.method.annotation.RequestMappingHandlerMapping;
 import org.springframework.web.reactive.method.annotation.ResponseBodyResultHandler;
-import org.springframework.web.server.DefaultWebServerExchange;
-import org.springframework.web.server.ExceptionHandlingWebHandler;
-import org.springframework.web.server.FilteringWebHandler;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
+import org.springframework.web.server.handler.ExceptionHandlingWebHandler;
+import org.springframework.web.server.handler.FilteringWebHandler;
 import org.springframework.web.server.WebExceptionHandler;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;

spring-web-reactive/src/test/java/org/springframework/web/reactive/ResponseStatusExceptionHandlerTests.java

@@ -29,7 +29,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.server.reactive.MockServerHttpRequest;
 import org.springframework.http.server.reactive.MockServerHttpResponse;
 import org.springframework.web.ResponseStatusException;
-import org.springframework.web.server.DefaultWebServerExchange;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
 import org.springframework.web.server.WebServerExchange;
 import org.springframework.web.server.session.WebSessionManager;
 

spring-web-reactive/src/test/java/org/springframework/web/reactive/handler/SimpleUrlHandlerMappingIntegrationTests.java

@@ -40,7 +40,7 @@ import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.ResponseStatusExceptionHandler;
 import org.springframework.web.server.WebHandler;
 import org.springframework.web.server.WebServerExchange;
-import org.springframework.web.server.WebToHttpHandlerBuilder;
+import org.springframework.web.server.adapter.WebToHttpHandlerBuilder;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;

spring-web-reactive/src/test/java/org/springframework/web/reactive/method/InvocableHandlerMethodTests.java

@@ -35,7 +35,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.reactive.HandlerResult;
 import org.springframework.web.reactive.method.annotation.RequestParamArgumentResolver;
-import org.springframework.web.server.DefaultWebServerExchange;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
 import org.springframework.web.server.WebServerExchange;
 import org.springframework.web.server.session.WebSessionManager;
 

spring-web-reactive/src/test/java/org/springframework/web/reactive/method/annotation/RequestMappingHandlerMappingTests.java

@@ -34,7 +34,7 @@ import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.method.HandlerMethod;
-import org.springframework.web.server.DefaultWebServerExchange;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
 import org.springframework.web.server.WebServerExchange;
 import org.springframework.web.server.session.WebSessionManager;
 

spring-web-reactive/src/test/java/org/springframework/web/reactive/method/annotation/RequestMappingIntegrationTests.java

@@ -64,7 +64,7 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.handler.SimpleHandlerResultHandler;
-import org.springframework.web.server.WebToHttpHandlerBuilder;
+import org.springframework.web.server.adapter.WebToHttpHandlerBuilder;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;

spring-web-reactive/src/test/java/org/springframework/web/server/handler/ExceptionHandlingHttpHandlerTests.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.handler;
 
 
 import java.net.URI;
@@ -26,6 +26,11 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.server.reactive.MockServerHttpRequest;
 import org.springframework.http.server.reactive.MockServerHttpResponse;
+import org.springframework.web.server.WebExceptionHandler;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.WebServerExchange;
+import org.springframework.web.server.handler.ExceptionHandlingWebHandler;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
 import org.springframework.web.server.session.WebSessionManager;
 
 import static org.junit.Assert.assertEquals;

spring-web-reactive/src/test/java/org/springframework/web/server/handler/FilteringWebHandlerTests.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.web.server;
+package org.springframework.web.server.handler;
 
 
 import java.net.URI;
@@ -30,10 +30,14 @@ import org.springframework.http.server.reactive.MockServerHttpRequest;
 import org.springframework.http.server.reactive.MockServerHttpResponse;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.WebServerExchange;
+import org.springframework.web.server.adapter.WebToHttpHandlerBuilder;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.mockito.Mockito.mock;
 
 /**
  * @author Rossen Stoyanchev
@@ -104,7 +108,7 @@ public class FilteringWebHandlerTests {
 		assertTrue(webHandler.invoked());
 	}
 
-	private WebToHttpHandlerAdapter createHttpHandler(StubWebHandler webHandler, WebFilter... filters) {
+	private HttpHandler createHttpHandler(StubWebHandler webHandler, WebFilter... filters) {
 		return WebToHttpHandlerBuilder.webHandler(webHandler).filters(filters).build();
 	}
 

spring-web-reactive/src/test/java/org/springframework/web/server/session/DefaultWebSessionManagerTests.java

@@ -27,7 +27,7 @@ import org.junit.Test;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.server.reactive.MockServerHttpRequest;
 import org.springframework.http.server.reactive.MockServerHttpResponse;
-import org.springframework.web.server.DefaultWebServerExchange;
+import org.springframework.web.server.adapter.DefaultWebServerExchange;
 import org.springframework.web.server.WebServerExchange;
 import org.springframework.web.server.WebSession;
 
@@ -37,7 +37,6 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
 
 /**
  * @author Rossen Stoyanchev
@@ -74,7 +73,7 @@ public class DefaultWebSessionManagerTests {
 
 		session.save();
 
-		assertFalse(this.idResolver.getId().isPresent());
+		assertNull(this.idResolver.getId());
 		assertNull(this.manager.getSessionStore().retrieveSession(session.getId()).get());
 	}
 
@@ -86,8 +85,8 @@ public class DefaultWebSessionManagerTests {
 		session.save();
 
 		String id = session.getId();
-		assertTrue(this.idResolver.getId().isPresent());
-		assertEquals(id, this.idResolver.getId().get());
+		assertNotNull(this.idResolver.getId());
+		assertEquals(id, this.idResolver.getId());
 		assertSame(session, this.manager.getSessionStore().retrieveSession(id).get());
 	}
 
@@ -98,7 +97,7 @@ public class DefaultWebSessionManagerTests {
 		session.getAttributes().put("foo", "bar");
 		session.save();
 
-		assertTrue(this.idResolver.getId().isPresent());
+		assertNotNull(this.idResolver.getId());
 	}
 
 	@Test
@@ -129,14 +128,14 @@ public class DefaultWebSessionManagerTests {
 
 		private Optional<String> idToResolve = Optional.empty();
 
-		private Optional<String> id = Optional.empty();
+		private String id = null;
 
 
 		public void setIdToResolve(Optional<String> idToResolve) {
 			this.idToResolve = idToResolve;
 		}
 
-		public Optional<String> getId() {
+		public String getId() {
 			return this.id;
 		}
 
@@ -146,7 +145,7 @@ public class DefaultWebSessionManagerTests {
 		}
 
 		@Override
-		public void setSessionId(WebServerExchange exchange, Optional<String> sessionId) {
+		public void setSessionId(WebServerExchange exchange, String sessionId) {
 			this.id = sessionId;
 		}
 	}

spring-web-reactive/src/test/java/org/springframework/web/server/session/WebSessionIntegrationTests.java

@@ -37,7 +37,7 @@ import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.server.WebHandler;
 import org.springframework.web.server.WebServerExchange;
-import org.springframework.web.server.WebToHttpHandlerBuilder;
+import org.springframework.web.server.adapter.WebToHttpHandlerBuilder;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;