WebHttpHandlerBuilder retains ApplicationContext in copy constructor

Issue: SPR-16972

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -79,6 +79,9 @@ public class WebHttpHandlerBuilder {
 
 	private final WebHandler webHandler;
 
+	@Nullable
+	private final ApplicationContext applicationContext;
+
 	private final List<WebFilter> filters = new ArrayList<>();
 
 	private final List<WebExceptionHandler> exceptionHandlers = new ArrayList<>();
@@ -92,22 +95,11 @@ public class WebHttpHandlerBuilder {
 	@Nullable
 	private LocaleContextResolver localeContextResolver;
 
-	@Nullable
-	private ApplicationContext applicationContext;
-
-
-	/**
-	 * Private constructor.
-	 */
-	private WebHttpHandlerBuilder(WebHandler webHandler) {
-		Assert.notNull(webHandler, "WebHandler must not be null");
-		this.webHandler = webHandler;
-	}
 
 	/**
 	 * Private constructor to use when initialized from an ApplicationContext.
 	 */
-	private WebHttpHandlerBuilder(WebHandler webHandler, ApplicationContext applicationContext) {
+	private WebHttpHandlerBuilder(WebHandler webHandler, @Nullable ApplicationContext applicationContext) {
 		Assert.notNull(webHandler, "WebHandler must not be null");
 		this.webHandler = webHandler;
 		this.applicationContext = applicationContext;
@@ -118,6 +110,7 @@ public class WebHttpHandlerBuilder {
 	 */
 	private WebHttpHandlerBuilder(WebHttpHandlerBuilder other) {
 		this.webHandler = other.webHandler;
+		this.applicationContext = other.applicationContext;
 		this.filters.addAll(other.filters);
 		this.exceptionHandlers.addAll(other.exceptionHandlers);
 		this.sessionManager = other.sessionManager;
@@ -132,7 +125,7 @@ public class WebHttpHandlerBuilder {
 	 * @return the prepared builder
 	 */
 	public static WebHttpHandlerBuilder webHandler(WebHandler webHandler) {
-		return new WebHttpHandlerBuilder(webHandler);
+		return new WebHttpHandlerBuilder(webHandler, null);
 	}
 
 	/**
@@ -156,7 +149,6 @@ public class WebHttpHandlerBuilder {
 	 * @return the prepared builder
 	 */
 	public static WebHttpHandlerBuilder applicationContext(ApplicationContext context) {
-
 		WebHttpHandlerBuilder builder = new WebHttpHandlerBuilder(
 				context.getBean(WEB_HANDLER_BEAN_NAME, WebHandler.class), context);
 
@@ -272,13 +264,10 @@ public class WebHttpHandlerBuilder {
 	 * Build the {@link HttpHandler}.
 	 */
 	public HttpHandler build() {
-
-		WebHandler decorated;
-		decorated = new FilteringWebHandler(this.webHandler, this.filters);
+		WebHandler decorated = new FilteringWebHandler(this.webHandler, this.filters);
 		decorated = new ExceptionHandlingWebHandler(decorated,  this.exceptionHandlers);
 
 		HttpWebHandlerAdapter adapted = new HttpWebHandlerAdapter(decorated);
-
 		if (this.sessionManager != null) {
 			adapted.setSessionManager(this.sessionManager);
 		}
@@ -291,7 +280,6 @@ public class WebHttpHandlerBuilder {
 		if (this.applicationContext != null) {
 			adapted.setApplicationContext(this.applicationContext);
 		}
-
 		adapted.afterPropertiesSet();
 
 		return adapted;

spring-web/src/test/java/org/springframework/web/server/adapter/WebHttpHandlerBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,10 +36,8 @@ import org.springframework.web.server.WebExceptionHandler;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebHandler;
 
-import static java.time.Duration.ofMillis;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
+import static java.time.Duration.*;
+import static org.junit.Assert.*;
 
 /**
  * Unit tests for {@link WebHttpHandlerBuilder}.
@@ -48,13 +46,12 @@ import static org.junit.Assert.assertTrue;
 public class WebHttpHandlerBuilderTests {
 
 	@Test  // SPR-15074
-	public void orderedWebFilterBeans() throws Exception {
+	public void orderedWebFilterBeans() {
 		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
 		context.register(OrderedWebFilterBeanConfig.class);
 		context.refresh();
 
 		HttpHandler httpHandler = WebHttpHandlerBuilder.applicationContext(context).build();
-
 		assertTrue(httpHandler instanceof HttpWebHandlerAdapter);
 		assertSame(context, ((HttpWebHandlerAdapter) httpHandler).getApplicationContext());
 
@@ -66,13 +63,12 @@ public class WebHttpHandlerBuilderTests {
 	}
 
 	@Test  // SPR-15074
-	public void orderedWebExceptionHandlerBeans() throws Exception {
+	public void orderedWebExceptionHandlerBeans() {
 		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
 		context.register(OrderedExceptionHandlerBeanConfig.class);
 		context.refresh();
 
 		HttpHandler httpHandler = WebHttpHandlerBuilder.applicationContext(context).build();
-
 		MockServerHttpRequest request = MockServerHttpRequest.get("/").build();
 		MockServerHttpResponse response = new MockServerHttpResponse();
 		httpHandler.handle(request, response).block(ofMillis(5000));
@@ -81,13 +77,12 @@ public class WebHttpHandlerBuilderTests {
 	}
 
 	@Test
-	public void configWithoutFilters() throws Exception {
+	public void configWithoutFilters() {
 		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
 		context.register(NoFilterConfig.class);
 		context.refresh();
 
 		HttpHandler httpHandler = WebHttpHandlerBuilder.applicationContext(context).build();
-
 		MockServerHttpRequest request = MockServerHttpRequest.get("/").build();
 		MockServerHttpResponse response = new MockServerHttpResponse();
 		httpHandler.handle(request, response).block(ofMillis(5000));
@@ -95,6 +90,17 @@ public class WebHttpHandlerBuilderTests {
 		assertEquals("handled", response.getBodyAsString().block(ofMillis(5000)));
 	}
 
+	@Test  // SPR-16972
+	public void cloneWithApplicationContext() {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		context.register(NoFilterConfig.class);
+		context.refresh();
+
+		WebHttpHandlerBuilder builder = WebHttpHandlerBuilder.applicationContext(context);
+		assertSame(context, ((HttpWebHandlerAdapter) builder.build()).getApplicationContext());
+		assertSame(context, ((HttpWebHandlerAdapter) builder.clone().build()).getApplicationContext());
+	}
+
 
 	private static Mono<Void> writeToResponse(ServerWebExchange exchange, String value) {
 		byte[] bytes = value.getBytes(StandardCharsets.UTF_8);