Update generics on WebMvc RouterFunctions.Builder

Same as 7555d0e489, but for WebMvc.

Closes gh-35791

spring-webmvc/src/main/java/org/springframework/web/servlet/function/RouterFunctionBuilder.java

@@ -38,6 +38,7 @@ import org.springframework.util.Assert;
  *
  * @author Arjen Poutsma
  * @author Sebastien Deleuze
+ * @author Rossen Stoyanchev
  * @since 5.2
  */
 class RouterFunctionBuilder implements RouterFunctions.Builder {
@@ -49,38 +50,38 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	private final List<HandlerFilterFunction<ServerResponse, ServerResponse>> errorHandlers = new ArrayList<>();
 
 
+	@SuppressWarnings("unchecked")
 	@Override
-	public RouterFunctions.Builder add(RouterFunction<ServerResponse> routerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder add(RouterFunction<T> routerFunction) {
 		Assert.notNull(routerFunction, "RouterFunction must not be null");
-		this.routerFunctions.add(routerFunction);
+		this.routerFunctions.add((RouterFunction<ServerResponse>) routerFunction);
 		return this;
 	}
 
-	private RouterFunctions.Builder add(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
-		this.routerFunctions.add(RouterFunctions.route(predicate, handlerFunction));
-		return this;
+	private <T extends ServerResponse> RouterFunctions.Builder add(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
+		return add(RouterFunctions.route(predicate, handlerFunction));
 	}
 
 	// GET
 
 	@Override
-	public RouterFunctions.Builder GET(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder GET(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.GET), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder GET(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder GET(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.GET).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder GET(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder GET(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.GET(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder GET(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder GET(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.GET(pattern).and(predicate), handlerFunction);
 	}
@@ -88,23 +89,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// HEAD
 
 	@Override
-	public RouterFunctions.Builder HEAD(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder HEAD(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.HEAD), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder HEAD(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder HEAD(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.HEAD).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder HEAD(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder HEAD(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.HEAD(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder HEAD(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder HEAD(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.HEAD(pattern).and(predicate), handlerFunction);
 	}
@@ -112,23 +113,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// POST
 
 	@Override
-	public RouterFunctions.Builder POST(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder POST(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.POST), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder POST(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder POST(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.POST).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder POST(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder POST(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.POST(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder POST(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder POST(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.POST(pattern).and(predicate), handlerFunction);
 	}
@@ -136,23 +137,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// PUT
 
 	@Override
-	public RouterFunctions.Builder PUT(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PUT(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.PUT), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PUT(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PUT(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.PUT).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PUT(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PUT(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.PUT(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PUT(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PUT(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.PUT(pattern).and(predicate), handlerFunction);
 	}
@@ -160,23 +161,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// PATCH
 
 	@Override
-	public RouterFunctions.Builder PATCH(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PATCH(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.PATCH), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PATCH(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PATCH(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.PATCH).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PATCH(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PATCH(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.PATCH(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder PATCH(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder PATCH(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.PATCH(pattern).and(predicate), handlerFunction);
 	}
@@ -184,23 +185,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// DELETE
 
 	@Override
-	public RouterFunctions.Builder DELETE(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder DELETE(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.DELETE), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder DELETE(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder DELETE(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.DELETE).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder DELETE(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder DELETE(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.DELETE(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder DELETE(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder DELETE(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.DELETE(pattern).and(predicate), handlerFunction);
 	}
@@ -208,23 +209,23 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// OPTIONS
 
 	@Override
-	public RouterFunctions.Builder OPTIONS(HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder OPTIONS(HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.OPTIONS), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder OPTIONS(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder OPTIONS(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.method(HttpMethod.OPTIONS).and(predicate), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder OPTIONS(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder OPTIONS(String pattern, HandlerFunction<T> handlerFunction) {
 		return add(RequestPredicates.OPTIONS(pattern), handlerFunction);
 	}
 
 	@Override
-	public RouterFunctions.Builder OPTIONS(String pattern, RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder OPTIONS(String pattern, RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 
 		return add(RequestPredicates.OPTIONS(pattern).and(predicate), handlerFunction);
 	}
@@ -232,8 +233,8 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	// other
 
 	@Override
-	public RouterFunctions.Builder route(RequestPredicate predicate,
-			HandlerFunction<ServerResponse> handlerFunction) {
+	public <T extends ServerResponse> RouterFunctions.Builder route(RequestPredicate predicate,
+			HandlerFunction<T> handlerFunction) {
 		return add(RouterFunctions.route(predicate, handlerFunction));
 	}
 
@@ -285,13 +286,14 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 		return this;
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
-	public RouterFunctions.Builder nest(RequestPredicate predicate,
-			Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier) {
+	public <T extends ServerResponse> RouterFunctions.Builder nest(RequestPredicate predicate,
+			Supplier<RouterFunction<T>> routerFunctionSupplier) {
 
 		Assert.notNull(routerFunctionSupplier, "RouterFunction Supplier must not be null");
 
-		RouterFunction<ServerResponse> nestedRoute = routerFunctionSupplier.get();
+		RouterFunction<ServerResponse> nestedRoute = (RouterFunction<ServerResponse>) routerFunctionSupplier.get();
 		this.routerFunctions.add(RouterFunctions.nest(predicate, nestedRoute));
 		return this;
 	}
@@ -304,17 +306,18 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	}
 
 	@Override
-	public RouterFunctions.Builder path(String pattern,
-			Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier) {
+	public <T extends ServerResponse> RouterFunctions.Builder path(String pattern,
+			Supplier<RouterFunction<T>> routerFunctionSupplier) {
 
 		return nest(RequestPredicates.path(pattern), routerFunctionSupplier);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
-	public RouterFunctions.Builder filter(HandlerFilterFunction<ServerResponse, ServerResponse> filterFunction) {
+	public <T extends ServerResponse, R extends ServerResponse> RouterFunctions.Builder filter(HandlerFilterFunction<T, R> filterFunction) {
 		Assert.notNull(filterFunction, "HandlerFilterFunction must not be null");
 
-		this.filterFunctions.add(filterFunction);
+		this.filterFunctions.add((HandlerFilterFunction<ServerResponse, ServerResponse>) filterFunction);
 		return this;
 	}
 
@@ -325,27 +328,29 @@ class RouterFunctionBuilder implements RouterFunctions.Builder {
 	}
 
 	@Override
-	public RouterFunctions.Builder after(
-			BiFunction<ServerRequest, ServerResponse, ServerResponse> responseProcessor) {
+	public <T extends ServerResponse, R extends ServerResponse> RouterFunctions.Builder after(
+			BiFunction<ServerRequest, T, R> responseProcessor) {
 
 		Assert.notNull(responseProcessor, "ResponseProcessor must not be null");
 		return filter(HandlerFilterFunction.ofResponseProcessor(responseProcessor));
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
-	public RouterFunctions.Builder onError(Predicate<Throwable> predicate,
-			BiFunction<Throwable, ServerRequest, ServerResponse> responseProvider) {
+	public <T extends ServerResponse> RouterFunctions.Builder onError(Predicate<Throwable> predicate,
+			BiFunction<Throwable, ServerRequest, T> responseProvider) {
 
 		Assert.notNull(predicate, "Predicate must not be null");
 		Assert.notNull(responseProvider, "ResponseProvider must not be null");
 
-		this.errorHandlers.add(0, HandlerFilterFunction.ofErrorHandler(predicate, responseProvider));
+		HandlerFilterFunction<T, T> filter = HandlerFilterFunction.ofErrorHandler(predicate, responseProvider);
+		this.errorHandlers.add(0, (HandlerFilterFunction<ServerResponse, ServerResponse>) filter);
 		return this;
 	}
 
 	@Override
-	public RouterFunctions.Builder onError(Class<? extends Throwable> exceptionType,
-			BiFunction<Throwable, ServerRequest, ServerResponse> responseProvider) {
+	public <T extends ServerResponse> RouterFunctions.Builder onError(Class<? extends Throwable> exceptionType,
+			BiFunction<Throwable, ServerRequest, T> responseProvider) {
 		Assert.notNull(exceptionType, "ExceptionType must not be null");
 		Assert.notNull(responseProvider, "ResponseProvider must not be null");
 

spring-webmvc/src/main/java/org/springframework/web/servlet/function/RouterFunctions.java

@@ -46,6 +46,7 @@ import org.springframework.web.util.pattern.PathPatternParser;
  *
  * @author Arjen Poutsma
  * @author Sebastien Deleuze
+ * @author Rossen Stoyanchev
  * @since 5.2
  */
 public abstract class RouterFunctions {
@@ -282,7 +283,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder GET(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder GET(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code GET} requests
@@ -293,7 +294,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder GET(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder GET(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code GET} requests
@@ -305,7 +306,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder GET(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder GET(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code GET} requests
@@ -326,7 +327,7 @@ public abstract class RouterFunctions {
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 * @see RequestPredicates
 		 */
-		Builder GET(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder GET(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code HEAD} requests.
@@ -334,7 +335,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder HEAD(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder HEAD(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code HEAD} requests
@@ -345,7 +346,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder HEAD(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder HEAD(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code HEAD} requests
@@ -357,7 +358,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder HEAD(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder HEAD(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code HEAD} requests
@@ -369,7 +370,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder HEAD(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder HEAD(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code POST} requests.
@@ -377,7 +378,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder POST(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder POST(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code POST} requests
@@ -388,7 +389,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder POST(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder POST(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code POST} requests
@@ -400,7 +401,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder POST(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder POST(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code POST} requests
@@ -420,7 +421,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder POST(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder POST(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code PUT} requests.
@@ -428,7 +429,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder PUT(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PUT(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PUT} requests
@@ -439,7 +440,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder PUT(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PUT(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PUT} requests
@@ -451,7 +452,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder PUT(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PUT(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PUT} requests
@@ -471,7 +472,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder PUT(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PUT(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code PATCH} requests.
@@ -479,7 +480,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder PATCH(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PATCH(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PATCH} requests
@@ -490,7 +491,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder PATCH(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PATCH(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PATCH} requests
@@ -502,7 +503,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder PATCH(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PATCH(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code PATCH} requests
@@ -522,7 +523,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder PATCH(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder PATCH(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code DELETE} requests.
@@ -530,7 +531,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder DELETE(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder DELETE(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code DELETE} requests
@@ -541,7 +542,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder DELETE(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder DELETE(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code DELETE} requests
@@ -553,7 +554,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder DELETE(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder DELETE(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code DELETE} requests
@@ -565,7 +566,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder DELETE(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder DELETE(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles HTTP {@code OPTIONS} requests.
@@ -573,7 +574,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @since 5.3
 		 */
-		Builder OPTIONS(HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder OPTIONS(HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code OPTIONS} requests
@@ -584,7 +585,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder OPTIONS(String pattern, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder OPTIONS(String pattern, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code OPTIONS} requests
@@ -596,7 +597,7 @@ public abstract class RouterFunctions {
 		 * @since 5.3
 		 * @see RequestPredicates
 		 */
-		Builder OPTIONS(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder OPTIONS(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all HTTP {@code OPTIONS} requests
@@ -608,7 +609,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder OPTIONS(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder OPTIONS(String pattern, RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds a route to the given handler function that handles all requests that match the
@@ -618,7 +619,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see RequestPredicates
 		 */
-		Builder route(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction);
+		<T extends ServerResponse> Builder route(RequestPredicate predicate, HandlerFunction<T> handlerFunction);
 
 		/**
 		 * Adds the given route to this builder. Can be used to merge externally defined router
@@ -639,7 +640,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see RequestPredicates
 		 */
-		Builder add(RouterFunction<ServerResponse> routerFunction);
+		<T extends ServerResponse> Builder add(RouterFunction<T> routerFunction);
 
 		/**
 		 * Route requests that match the given predicate to the given resource.
@@ -743,7 +744,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see RequestPredicates
 		 */
-		Builder nest(RequestPredicate predicate, Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier);
+		<T extends ServerResponse> Builder nest(RequestPredicate predicate, Supplier<RouterFunction<T>> routerFunctionSupplier);
 
 		/**
 		 * Route to a built router function if the given request predicate applies.
@@ -789,7 +790,7 @@ public abstract class RouterFunctions {
 		 * @return this builder
 		 * @see org.springframework.web.util.pattern.PathPattern
 		 */
-		Builder path(String pattern, Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier);
+		<T extends ServerResponse> Builder path(String pattern, Supplier<RouterFunction<T>> routerFunctionSupplier);
 
 		/**
 		 * Route to a built router function if the given path prefix pattern applies.
@@ -838,7 +839,7 @@ public abstract class RouterFunctions {
 		 * @param filterFunction the function to filter all routes built by this builder
 		 * @return this builder
 		 */
-		Builder filter(HandlerFilterFunction<ServerResponse, ServerResponse> filterFunction);
+		<T extends ServerResponse, R extends ServerResponse> Builder filter(HandlerFilterFunction<T, R> filterFunction);
 
 		/**
 		 * Filter the request object for all routes created by this builder with the given request
@@ -880,7 +881,7 @@ public abstract class RouterFunctions {
 		 * @param responseProcessor a function that transforms the response
 		 * @return this builder
 		 */
-		Builder after(BiFunction<ServerRequest, ServerResponse, ServerResponse> responseProcessor);
+		<T extends ServerResponse, R extends ServerResponse> Builder after(BiFunction<ServerRequest, T, R> responseProcessor);
 
 		/**
 		 * Filters all exceptions that match the predicate by applying the given response provider
@@ -899,8 +900,8 @@ public abstract class RouterFunctions {
 		 * @param responseProvider a function that creates a response
 		 * @return this builder
 		 */
-		Builder onError(Predicate<Throwable> predicate,
-				BiFunction<Throwable, ServerRequest, ServerResponse> responseProvider);
+		<T extends ServerResponse> Builder onError(Predicate<Throwable> predicate,
+				BiFunction<Throwable, ServerRequest, T> responseProvider);
 
 		/**
 		 * Filters all exceptions of the given type by applying the given response provider
@@ -919,8 +920,8 @@ public abstract class RouterFunctions {
 		 * @param responseProvider a function that creates a response
 		 * @return this builder
 		 */
-		Builder onError(Class<? extends Throwable> exceptionType,
-				BiFunction<Throwable, ServerRequest, ServerResponse> responseProvider);
+		<T extends ServerResponse> Builder onError(Class<? extends Throwable> exceptionType,
+				BiFunction<Throwable, ServerRequest, T> responseProvider);
 
 		/**
 		 * Add an attribute with the given name and value to the last route built with this builder.