springboot webflux 简介

快来打我* 2023-02-18 11:53 10阅读 0赞

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### springboot webflux 简介 ###

**官网：[https://docs.spring.io/spring-boot/docs/2.3.0.RELEASE/reference/html/spring-boot-features.html\#boot-features-webflux][https_docs.spring.io_spring-boot_docs_2.3.0.RELEASE_reference_html_spring-boot-features.html_boot-features-webflux]**

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**简介**

![format_png][]

**基于reactor实现的异步非阻塞框架，较同步阻塞的MVC框架，可提升系统性能；**

**可使用MVC的注解操作，也可使用函数式编程；**

**支持传统的servlet容器，还可运行在支持nio的netty、undertow容器中**

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**相关类与接口**

**ServerWebExchange：获取request、response、session**

public interface ServerWebExchange {
        String LOG_ID_ATTRIBUTE = ServerWebExchange.class.getName() + ".LOG_ID";
    
        ServerHttpRequest getRequest();        //获取request
        ServerHttpResponse getResponse();      //获取response
        Map<String, Object> getAttributes();   //获取请求中的属性
    
        @Nullable
        default <T> T getAttribute(String name) {
            return this.getAttributes().get(name);
        }
    
        default <T> T getRequiredAttribute(String name) {
            T value = this.getAttribute(name);
            Assert.notNull(value, () -> {
                return "Required attribute '" + name + "' is missing";
            });
            return value;
        }
    
        default <T> T getAttributeOrDefault(String name, T defaultValue) {
            return this.getAttributes().getOrDefault(name, defaultValue);
        }
    
        Mono<WebSession> getSession();                 //获取webSession
        <T extends Principal> Mono<T> getPrincipal();  //获取认证用户
    
        Mono<MultiValueMap<String, String>> getFormData();      //获取表单参数
        Mono<MultiValueMap<String, Part>> getMultipartData();   //获取表单multipart数据
    
        LocaleContext getLocaleContext();              //获取国际化设置（Locale）
    
        @Nullable
        ApplicationContext getApplicationContext();    //获取应用上下文
    
        boolean isNotModified();
        boolean checkNotModified(Instant var1);
        boolean checkNotModified(String var1);
        boolean checkNotModified(@Nullable String var1, Instant var2);
    
        String transformUrl(String var1);
        void addUrlTransformer(Function<String, String> var1);
    
        String getLogPrefix();
    
        default ServerWebExchange.Builder mutate() {
            return new DefaultServerWebExchangeBuilder(this);
        }
    
        public interface Builder {           //构造ServeraWebExchange
            ServerWebExchange.Builder request(Consumer<org.springframework.http.server.reactive.ServerHttpRequest.Builder> var1);
    
            ServerWebExchange.Builder request(ServerHttpRequest var1);       //设置请求
            ServerWebExchange.Builder response(ServerHttpResponse var1);     //设置响应
    
            ServerWebExchange.Builder principal(Mono<Principal> var1);       //设置认证用户
            ServerWebExchange build();                                       //返回ServerWebExchange
        }
    }

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**ServerHttpRequest**

public interface ServerHttpRequest extends HttpRequest, ReactiveHttpInputMessage {
        String getId();
    
        RequestPath getPath();
        MultiValueMap<String, String> getQueryParams();
        MultiValueMap<String, HttpCookie> getCookies();
    
        @Nullable
        default InetSocketAddress getLocalAddress() {
            return null;
        }
    
        @Nullable
        default InetSocketAddress getRemoteAddress() {
            return null;
        }
    
        @Nullable
        default SslInfo getSslInfo() {
            return null;
        }
    
        default ServerHttpRequest.Builder mutate() {
            return new DefaultServerHttpRequestBuilder(this);
        }
    
        public interface Builder {
            ServerHttpRequest.Builder method(HttpMethod var1);
            ServerHttpRequest.Builder uri(URI var1);
            ServerHttpRequest.Builder path(String var1);
            ServerHttpRequest.Builder contextPath(String var1);
    
            ServerHttpRequest.Builder header(String var1, String... var2);
            ServerHttpRequest.Builder headers(Consumer<HttpHeaders> var1);
    
            ServerHttpRequest.Builder sslInfo(SslInfo var1);
            ServerHttpRequest build();
        }
    }

**HttpRequest**

public interface HttpRequest extends HttpMessage {
        @Nullable
        default HttpMethod getMethod() {
            return HttpMethod.resolve(this.getMethodValue());  //将请求方法转换为HttpMethod
        }
    
        String getMethodValue();        //获取请求方法
        URI getURI();                   //获取请求uri
    }

**HttpMessage**

public interface HttpMessage {
        HttpHeaders getHeaders();   //获取请求头
    }

**ReactiveHttpInputMessage**

public interface ReactiveHttpInputMessage extends HttpMessage {
        Flux<DataBuffer> getBody();
    }

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**ServerHttpResponse**

public interface ServerHttpResponse extends ReactiveHttpOutputMessage {
        boolean setStatusCode(@Nullable HttpStatus var1);
    
        @Nullable
        HttpStatus getStatusCode();
    
        default boolean setRawStatusCode(@Nullable Integer value) {
            if (value == null) {
                return this.setStatusCode((HttpStatus)null);
            } else {
                HttpStatus httpStatus = HttpStatus.resolve(value);
                if (httpStatus == null) {
                    throw new IllegalStateException("Unresolvable HttpStatus for general ServerHttpResponse: " + value);
                } else {
                    return this.setStatusCode(httpStatus);
                }
            }
        }
    
        @Nullable
        default Integer getRawStatusCode() {
            HttpStatus httpStatus = this.getStatusCode();
            return httpStatus != null ? httpStatus.value() : null;
        }
    
        MultiValueMap<String, ResponseCookie> getCookies();
        void addCookie(ResponseCookie var1);
    }

**ReactiveHttpOutputMess****age**

public interface ReactiveHttpOutputMessage extends HttpMessage {
        DataBufferFactory bufferFactory();
    
        void beforeCommit(Supplier<? extends Mono<Void>> var1);
        boolean isCommitted();
    
        Mono<Void> writeWith(Publisher<? extends DataBuffer> var1);
        Mono<Void> writeAndFlushWith(Publisher<? extends Publisher<? extends DataBuffer>> var1);
    
        Mono<Void> setComplete();
    }

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**WebSession**

**webSession：存储应用session数据**

public interface WebSession {
        String getId();
    
        Map<String, Object> getAttributes();
    
        @Nullable
        default <T> T getAttribute(String name) {
            return this.getAttributes().get(name);
        }
    
        default <T> T getRequiredAttribute(String name) {
            T value = this.getAttribute(name);
            Assert.notNull(value, () -> {
                return "Required attribute '" + name + "' is missing.";
            });
            return value;
        }
    
        default <T> T getAttributeOrDefault(String name, T defaultValue) {
            return this.getAttributes().getOrDefault(name, defaultValue);
        }
    
        void start();
        boolean isStarted();
    
        Mono<Void> changeSessionId();
    
        Mono<Void> invalidate();
        Mono<Void> save();
    
        boolean isExpired();
        Instant getCreationTime();
        Instant getLastAccessTime();
    
        void setMaxIdleTime(Duration var1);
        Duration getMaxIdleTime();
    }

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**context信息**

**LocaleContext：国际化上下文**

public interface LocaleContext {
        @Nullable
        Locale getLocale();
    }

**ApplicationContext：应用上下文**

public interface ApplicationContext extends EnvironmentCapable, ListableBeanFactory, HierarchicalBeanFactory, MessageSource, ApplicationEventPublisher, ResourcePatternResolver {
        @Nullable
        String getId();
        String getApplicationName();
    
        String getDisplayName();
        long getStartupDate();
    
        @Nullable
        ApplicationContext getParent();
        AutowireCapableBeanFactory getAutowireCapableBeanFactory() throws IllegalStateException;
    }

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**函数式类与接口**

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**RouterFunction**

@FunctionalInterface
    public interface RouterFunction<T extends ServerResponse> {
        Mono<HandlerFunction<T>> route(ServerRequest var1);
    
        default RouterFunction<T> and(RouterFunction<T> other) {
            return new SameComposedRouterFunction(this, other);
        }
    
        default RouterFunction<?> andOther(RouterFunction<?> other) {
            return new DifferentComposedRouterFunction(this, other);
        }
    
        default RouterFunction<T> andRoute(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
            return this.and(RouterFunctions.route(predicate, handlerFunction));
        }
    
        default RouterFunction<T> andNest(RequestPredicate predicate, RouterFunction<T> routerFunction) {
            return this.and(RouterFunctions.nest(predicate, routerFunction));
        }
    
        default <S extends ServerResponse> RouterFunction<S> filter(HandlerFilterFunction<T, S> filterFunction) {
            return new FilteredRouterFunction(this, filterFunction);
        }
    
        default void accept(Visitor visitor) {
            visitor.unknown(this);
        }
    }

**RouterFunctionBuilder：构造RouterFunction**

class RouterFunctionBuilder implements Builder {
        private List<RouterFunction<ServerResponse>> routerFunctions = new ArrayList();
        private List<HandlerFilterFunction<ServerResponse, ServerResponse>> filterFunctions = new ArrayList();
    
        RouterFunctionBuilder() {
        }
    
        public Builder add(RouterFunction<ServerResponse> routerFunction) {
            Assert.notNull(routerFunction, "RouterFunction must not be null");
            this.routerFunctions.add(routerFunction);
            return this;
        }
    
        private Builder add(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            this.routerFunctions.add(RouterFunctions.route(predicate, handlerFunction));
            return this;
        }
    
        public Builder GET(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.GET(pattern), handlerFunction);
        }
    
        public Builder GET(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.GET(pattern).and(predicate), handlerFunction);
        }
    
        public Builder HEAD(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.HEAD(pattern), handlerFunction);
        }
    
        public Builder HEAD(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.HEAD(pattern).and(predicate), handlerFunction);
        }
    
        public Builder POST(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.POST(pattern), handlerFunction);
        }
    
        public Builder POST(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.POST(pattern).and(predicate), handlerFunction);
        }
    
        public Builder PUT(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.PUT(pattern), handlerFunction);
        }
    
        public Builder PUT(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.PUT(pattern).and(predicate), handlerFunction);
        }
    
        public Builder PATCH(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.PATCH(pattern), handlerFunction);
        }
    
        public Builder PATCH(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.PATCH(pattern).and(predicate), handlerFunction);
        }
    
        public Builder DELETE(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.DELETE(pattern), handlerFunction);
        }
    
        public Builder DELETE(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.DELETE(pattern).and(predicate), handlerFunction);
        }
    
        public Builder OPTIONS(String pattern, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.OPTIONS(pattern), handlerFunction);
        }
    
        public Builder OPTIONS(String pattern, RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RequestPredicates.OPTIONS(pattern).and(predicate), handlerFunction);
        }
    
        public Builder route(RequestPredicate predicate, HandlerFunction<ServerResponse> handlerFunction) {
            return this.add(RouterFunctions.route(predicate, handlerFunction));
        }
    
        public Builder resources(String pattern, Resource location) {
            return this.add(RouterFunctions.resources(pattern, location));
        }
    
        public Builder resources(Function<ServerRequest, Mono<Resource>> lookupFunction) {
            return this.add(RouterFunctions.resources(lookupFunction));
        }
    
        public Builder nest(RequestPredicate predicate, Consumer<Builder> builderConsumer) {
            Assert.notNull(builderConsumer, "Consumer must not be null");
            RouterFunctionBuilder nestedBuilder = new RouterFunctionBuilder();
            builderConsumer.accept(nestedBuilder);
            RouterFunction<ServerResponse> nestedRoute = nestedBuilder.build();
            this.routerFunctions.add(RouterFunctions.nest(predicate, nestedRoute));
            return this;
        }
    
        public Builder nest(RequestPredicate predicate, Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier) {
            Assert.notNull(routerFunctionSupplier, "RouterFunction Supplier must not be null");
            RouterFunction<ServerResponse> nestedRoute = (RouterFunction)routerFunctionSupplier.get();
            this.routerFunctions.add(RouterFunctions.nest(predicate, nestedRoute));
            return this;
        }
    
        public Builder path(String pattern, Consumer<Builder> builderConsumer) {
            return this.nest(RequestPredicates.path(pattern), builderConsumer);
        }
    
        public Builder path(String pattern, Supplier<RouterFunction<ServerResponse>> routerFunctionSupplier) {
            return this.nest(RequestPredicates.path(pattern), routerFunctionSupplier);
        }
    
        public Builder filter(HandlerFilterFunction<ServerResponse, ServerResponse> filterFunction) {
            Assert.notNull(filterFunction, "HandlerFilterFunction must not be null");
            this.filterFunctions.add(filterFunction);
            return this;
        }
    
        public Builder before(Function<ServerRequest, ServerRequest> requestProcessor) {
            Assert.notNull(requestProcessor, "RequestProcessor must not be null");
            return this.filter((request, next) -> {
                return next.handle((ServerRequest)requestProcessor.apply(request));
            });
        }
    
        public Builder after(BiFunction<ServerRequest, ServerResponse, ServerResponse> responseProcessor) {
            Assert.notNull(responseProcessor, "ResponseProcessor must not be null");
            return this.filter((request, next) -> {
                return next.handle(request).map((serverResponse) -> {
                    return (ServerResponse)responseProcessor.apply(request, serverResponse);
                });
            });
        }
    
        public Builder onError(Predicate<? super Throwable> predicate, BiFunction<? super Throwable, ServerRequest, Mono<ServerResponse>> responseProvider) {
            Assert.notNull(predicate, "Predicate must not be null");
            Assert.notNull(responseProvider, "ResponseProvider must not be null");
            return this.filter((request, next) -> {
                return next.handle(request).onErrorResume(predicate, (t) -> {
                    return (Mono)responseProvider.apply(t, request);
                });
            });
        }
    
        public <T extends Throwable> Builder onError(Class<T> exceptionType, BiFunction<? super T, ServerRequest, Mono<ServerResponse>> responseProvider) {
            Assert.notNull(exceptionType, "ExceptionType must not be null");
            Assert.notNull(responseProvider, "ResponseProvider must not be null");
            return this.filter((request, next) -> {
                return next.handle(request).onErrorResume(exceptionType, (t) -> {
                    return (Mono)responseProvider.apply(t, request);
                });
            });
        }
    
        public RouterFunction<ServerResponse> build() {
            if (this.routerFunctions.isEmpty()) {
                throw new IllegalStateException("No routes registered. Register a route with GET(), POST(), etc.");
            } else {
                RouterFunction<ServerResponse> result = new RouterFunctionBuilder.BuiltRouterFunction(this.routerFunctions);
                if (this.filterFunctions.isEmpty()) {
                    return result;
                } else {
                    HandlerFilterFunction<ServerResponse, ServerResponse> filter = (HandlerFilterFunction)this.filterFunctions.stream().reduce(HandlerFilterFunction::andThen).orElseThrow(IllegalStateException::new);
                    return result.filter(filter);
                }
            }
        }
    
        private static class BuiltRouterFunction extends AbstractRouterFunction<ServerResponse> {
            private List<RouterFunction<ServerResponse>> routerFunctions;
    
            public BuiltRouterFunction(List<RouterFunction<ServerResponse>> routerFunctions) {
                Assert.notEmpty(routerFunctions, "RouterFunctions must not be empty");
                this.routerFunctions = routerFunctions;
            }
    
            public Mono<HandlerFunction<ServerResponse>> route(ServerRequest request) {
                return Flux.fromIterable(this.routerFunctions).concatMap((routerFunction) -> {
                    return routerFunction.route(request);
                }).next();
            }
    
            public void accept(Visitor visitor) {
                this.routerFunctions.forEach((routerFunction) -> {
                    routerFunction.accept(visitor);
                });
            }
        }
    }

**RouterFunctions：构造RouterFunction**

public abstract class RouterFunctions {
        private static final Log logger = LogFactory.getLog(RouterFunctions.class);
        public static final String REQUEST_ATTRIBUTE = RouterFunctions.class.getName() + ".request";
        public static final String URI_TEMPLATE_VARIABLES_ATTRIBUTE = RouterFunctions.class.getName() + ".uriTemplateVariables";
        public static final String MATCHING_PATTERN_ATTRIBUTE = RouterFunctions.class.getName() + ".matchingPattern";
    
        public RouterFunctions() {
        }
    
        public static RouterFunctions.Builder route() {
            return new RouterFunctionBuilder();
        }
    
        public static <T extends ServerResponse> RouterFunction<T> route(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
            return new RouterFunctions.DefaultRouterFunction(predicate, handlerFunction);
        }
    
        public static <T extends ServerResponse> RouterFunction<T> nest(RequestPredicate predicate, RouterFunction<T> routerFunction) {
            return new RouterFunctions.DefaultNestedRouterFunction(predicate, routerFunction);
        }
    
        public static RouterFunction<ServerResponse> resources(String pattern, Resource location) {
            return resources(resourceLookupFunction(pattern, location));
        }
    
        public static Function<ServerRequest, Mono<Resource>> resourceLookupFunction(String pattern, Resource location) {
            return new PathResourceLookupFunction(pattern, location);
        }
    
        public static RouterFunction<ServerResponse> resources(Function<ServerRequest, Mono<Resource>> lookupFunction) {
            return new RouterFunctions.ResourcesRouterFunction(lookupFunction);
        }
    
        public static HttpHandler toHttpHandler(RouterFunction<?> routerFunction) {
            return toHttpHandler(routerFunction, HandlerStrategies.withDefaults());
        }
    
        public static HttpHandler toHttpHandler(RouterFunction<?> routerFunction, HandlerStrategies strategies) {
            WebHandler webHandler = toWebHandler(routerFunction, strategies);
            return WebHttpHandlerBuilder.webHandler(webHandler).filters((filters) -> {
                filters.addAll(strategies.webFilters());
            }).exceptionHandlers((handlers) -> {
                handlers.addAll(strategies.exceptionHandlers());
            }).localeContextResolver(strategies.localeContextResolver()).build();
        }
    
        public static WebHandler toWebHandler(RouterFunction<?> routerFunction) {
            return toWebHandler(routerFunction, HandlerStrategies.withDefaults());
        }
    
        public static WebHandler toWebHandler(RouterFunction<?> routerFunction, HandlerStrategies strategies) {
            Assert.notNull(routerFunction, "RouterFunction must not be null");
            Assert.notNull(strategies, "HandlerStrategies must not be null");
            return new RouterFunctions.RouterFunctionWebHandler(strategies, routerFunction);
        }
    
        private static class RouterFunctionWebHandler implements WebHandler {
            private static final HandlerFunction<ServerResponse> NOT_FOUND_HANDLER = (request) -> {
                return ServerResponse.notFound().build();
            };
            private final HandlerStrategies strategies;
            private final RouterFunction<?> routerFunction;
    
            public RouterFunctionWebHandler(HandlerStrategies strategies, RouterFunction<?> routerFunction) {
                this.strategies = strategies;
                this.routerFunction = routerFunction;
            }
    
            public Mono<Void> handle(ServerWebExchange exchange) {
                return Mono.defer(() -> {
                    ServerRequest request = new DefaultServerRequest(exchange, this.strategies.messageReaders());
                    this.addAttributes(exchange, request);
                    return this.routerFunction.route(request).defaultIfEmpty(notFound()).flatMap((handlerFunction) -> {
                        return wrapException(() -> {
                            return handlerFunction.handle(request);
                        });
                    }).flatMap((response) -> {
                        return wrapException(() -> {
                            return response.writeTo(exchange, new RouterFunctions.HandlerStrategiesResponseContext(this.strategies));
                        });
                    });
                });
            }
    
            private void addAttributes(ServerWebExchange exchange, ServerRequest request) {
                Map<String, Object> attributes = exchange.getAttributes();
                attributes.put(RouterFunctions.REQUEST_ATTRIBUTE, request);
            }
    
            private static <T extends ServerResponse> HandlerFunction<T> notFound() {
                return NOT_FOUND_HANDLER;
            }
    
            private static <T> Mono<T> wrapException(Supplier<Mono<T>> supplier) {
                try {
                    return (Mono)supplier.get();
                } catch (Throwable var2) {
                    return Mono.error(var2);
                }
            }
        }
    
        private static class HandlerStrategiesResponseContext implements Context {
            private final HandlerStrategies strategies;
    
            public HandlerStrategiesResponseContext(HandlerStrategies strategies) {
                this.strategies = strategies;
            }
    
            public List<HttpMessageWriter<?>> messageWriters() {
                return this.strategies.messageWriters();
            }
    
            public List<ViewResolver> viewResolvers() {
                return this.strategies.viewResolvers();
            }
        }
    
        private static class ResourcesRouterFunction extends RouterFunctions.AbstractRouterFunction<ServerResponse> {
            private final Function<ServerRequest, Mono<Resource>> lookupFunction;
    
            public ResourcesRouterFunction(Function<ServerRequest, Mono<Resource>> lookupFunction) {
                Assert.notNull(lookupFunction, "Function must not be null");
                this.lookupFunction = lookupFunction;
            }
    
            public Mono<HandlerFunction<ServerResponse>> route(ServerRequest request) {
                return ((Mono)this.lookupFunction.apply(request)).map(ResourceHandlerFunction::new);
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                visitor.resources(this.lookupFunction);
            }
        }
    
        private static final class DefaultNestedRouterFunction<T extends ServerResponse> extends RouterFunctions.AbstractRouterFunction<T> {
            private final RequestPredicate predicate;
            private final RouterFunction<T> routerFunction;
    
            public DefaultNestedRouterFunction(RequestPredicate predicate, RouterFunction<T> routerFunction) {
                Assert.notNull(predicate, "Predicate must not be null");
                Assert.notNull(routerFunction, "RouterFunction must not be null");
                this.predicate = predicate;
                this.routerFunction = routerFunction;
            }
    
            public Mono<HandlerFunction<T>> route(ServerRequest serverRequest) {
                return (Mono)this.predicate.nest(serverRequest).map((nestedRequest) -> {
                    if (RouterFunctions.logger.isTraceEnabled()) {
                        String logPrefix = serverRequest.exchange().getLogPrefix();
                        RouterFunctions.logger.trace(logPrefix + String.format("Matched nested %s", this.predicate));
                    }
    
                    return this.routerFunction.route(nestedRequest).doOnNext((match) -> {
                        if (nestedRequest != serverRequest) {
                            serverRequest.attributes().clear();
                            serverRequest.attributes().putAll(nestedRequest.attributes());
                        }
    
                    });
                }).orElseGet(Mono::empty);
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                visitor.startNested(this.predicate);
                this.routerFunction.accept(visitor);
                visitor.endNested(this.predicate);
            }
        }
    
        private static final class DefaultRouterFunction<T extends ServerResponse> extends RouterFunctions.AbstractRouterFunction<T> {
            private final RequestPredicate predicate;
            private final HandlerFunction<T> handlerFunction;
    
            public DefaultRouterFunction(RequestPredicate predicate, HandlerFunction<T> handlerFunction) {
                Assert.notNull(predicate, "Predicate must not be null");
                Assert.notNull(handlerFunction, "HandlerFunction must not be null");
                this.predicate = predicate;
                this.handlerFunction = handlerFunction;
            }
    
            public Mono<HandlerFunction<T>> route(ServerRequest request) {
                if (this.predicate.test(request)) {
                    if (RouterFunctions.logger.isTraceEnabled()) {
                        String logPrefix = request.exchange().getLogPrefix();
                        RouterFunctions.logger.trace(logPrefix + String.format("Matched %s", this.predicate));
                    }
    
                    return Mono.just(this.handlerFunction);
                } else {
                    return Mono.empty();
                }
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                visitor.route(this.predicate, this.handlerFunction);
            }
        }
    
        static final class FilteredRouterFunction<T extends ServerResponse, S extends ServerResponse> implements RouterFunction<S> {
            private final RouterFunction<T> routerFunction;
            private final HandlerFilterFunction<T, S> filterFunction;
    
            public FilteredRouterFunction(RouterFunction<T> routerFunction, HandlerFilterFunction<T, S> filterFunction) {
                this.routerFunction = routerFunction;
                this.filterFunction = filterFunction;
            }
    
            public Mono<HandlerFunction<S>> route(ServerRequest request) {
                Mono var10000 = this.routerFunction.route(request);
                HandlerFilterFunction var10001 = this.filterFunction;
                var10001.getClass();
                return var10000.map(var10001::apply);
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                this.routerFunction.accept(visitor);
            }
    
            public String toString() {
                return this.routerFunction.toString();
            }
        }
    
        static final class DifferentComposedRouterFunction extends RouterFunctions.AbstractRouterFunction<ServerResponse> {
            private final RouterFunction<?> first;
            private final RouterFunction<?> second;
    
            public DifferentComposedRouterFunction(RouterFunction<?> first, RouterFunction<?> second) {
                this.first = first;
                this.second = second;
            }
    
            public Mono<HandlerFunction<ServerResponse>> route(ServerRequest request) {
                return Flux.concat(new Publisher[]{this.first.route(request), Mono.defer(() -> {
                    return this.second.route(request);
                })}).next().map(this::cast);
            }
    
            private <T extends ServerResponse> HandlerFunction<T> cast(HandlerFunction<?> handlerFunction) {
                return handlerFunction;
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                this.first.accept(visitor);
                this.second.accept(visitor);
            }
        }
    
        static final class SameComposedRouterFunction<T extends ServerResponse> extends RouterFunctions.AbstractRouterFunction<T> {
            private final RouterFunction<T> first;
            private final RouterFunction<T> second;
    
            public SameComposedRouterFunction(RouterFunction<T> first, RouterFunction<T> second) {
                this.first = first;
                this.second = second;
            }
    
            public Mono<HandlerFunction<T>> route(ServerRequest request) {
                return Flux.concat(new Publisher[]{this.first.route(request), Mono.defer(() -> {
                    return this.second.route(request);
                })}).next();
            }
    
            public void accept(RouterFunctions.Visitor visitor) {
                this.first.accept(visitor);
                this.second.accept(visitor);
            }
        }
    
        abstract static class AbstractRouterFunction<T extends ServerResponse> implements RouterFunction<T> {
            AbstractRouterFunction() {
            }
    
            public String toString() {
                ToStringVisitor visitor = new ToStringVisitor();
                this.accept(visitor);
                return visitor.toString();
            }
        }
    
        public interface Visitor {
            void startNested(RequestPredicate var1);
    
            void endNested(RequestPredicate var1);
    
            void route(RequestPredicate var1, HandlerFunction<?> var2);
    
            void resources(Function<ServerRequest, Mono<Resource>> var1);
    
            void unknown(RouterFunction<?> var1);
        }
    
        public interface Builder {      //构造routerFunction
            RouterFunctions.Builder GET(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder GET(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder HEAD(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder HEAD(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder POST(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder POST(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder PUT(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder PUT(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder PATCH(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder PATCH(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder DELETE(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder DELETE(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder OPTIONS(String var1, HandlerFunction<ServerResponse> var2);
            RouterFunctions.Builder OPTIONS(String var1, RequestPredicate var2, HandlerFunction<ServerResponse> var3);
    
            RouterFunctions.Builder route(RequestPredicate var1, HandlerFunction<ServerResponse> var2);
    
            RouterFunctions.Builder add(RouterFunction<ServerResponse> var1);
    
            RouterFunctions.Builder resources(String var1, Resource var2);
            RouterFunctions.Builder resources(Function<ServerRequest, Mono<Resource>> var1);
    
            RouterFunctions.Builder nest(RequestPredicate var1, Supplier<RouterFunction<ServerResponse>> var2);
            RouterFunctions.Builder nest(RequestPredicate var1, Consumer<RouterFunctions.Builder> var2);
    
            RouterFunctions.Builder path(String var1, Supplier<RouterFunction<ServerResponse>> var2);
            RouterFunctions.Builder path(String var1, Consumer<RouterFunctions.Builder> var2);
    
            RouterFunctions.Builder filter(HandlerFilterFunction<ServerResponse, ServerResponse> var1);
            RouterFunctions.Builder before(Function<ServerRequest, ServerRequest> var1);
            RouterFunctions.Builder after(BiFunction<ServerRequest, ServerResponse, ServerResponse> var1);
    
            RouterFunctions.Builder onError(Predicate<? super Throwable> var1, BiFunction<? super Throwable, ServerRequest, Mono<ServerResponse>> var2);
            <T extends Throwable> RouterFunctions.Builder onError(Class<T> var1, BiFunction<? super T, ServerRequest, Mono<ServerResponse>> var2);
    
            RouterFunction<ServerResponse> build();
        }
    }

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

**RequestPredicate**

@FunctionalInterface
    public interface RequestPredicate {
        boolean test(ServerRequest var1);
    
        default RequestPredicate and(RequestPredicate other) {
            return new AndRequestPredicate(this, other);
        }
    
        default RequestPredicate negate() {
            return new NegateRequestPredicate(this);
        }
    
        default RequestPredicate or(RequestPredicate other) {
            return new OrRequestPredicate(this, other);
        }
    
        default Optional<ServerRequest> nest(ServerRequest request) {
            return this.test(request) ? Optional.of(request) : Optional.empty();
        }
    
        default void accept(Visitor visitor) {
            visitor.unknown(this);
        }
    }

**RequestPredicates：构造RequestPredicate**

public abstract class RequestPredicates {
        private static final Log logger = LogFactory.getLog(RequestPredicates.class);
    
        public RequestPredicates() {
        }
    
        public static RequestPredicate all() {
            return (request) -> {
                return true;
            };
        }
    
        public static RequestPredicate method(HttpMethod httpMethod) {
            return new RequestPredicates.HttpMethodPredicate(httpMethod);
        }
    
        public static RequestPredicate methods(HttpMethod... httpMethods) {
            return new RequestPredicates.HttpMethodPredicate(httpMethods);
        }
    
        public static RequestPredicate path(String pattern) {
            Assert.notNull(pattern, "'pattern' must not be null");
            if (!pattern.isEmpty() && !pattern.startsWith("/")) {
                pattern = "/" + pattern;
            }
    
            return (RequestPredicate)pathPredicates(PathPatternParser.defaultInstance).apply(pattern);
        }
    
        public static Function<String, RequestPredicate> pathPredicates(PathPatternParser patternParser) {
            Assert.notNull(patternParser, "PathPatternParser must not be null");
            return (pattern) -> {
                return new RequestPredicates.PathPatternPredicate(patternParser.parse(pattern));
            };
        }
    
        public static RequestPredicate headers(Predicate<Headers> headersPredicate) {
            return new RequestPredicates.HeadersPredicate(headersPredicate);
        }
    
        public static RequestPredicate contentType(MediaType... mediaTypes) {
            Assert.notEmpty(mediaTypes, "'mediaTypes' must not be empty");
            return new RequestPredicates.ContentTypePredicate(mediaTypes);
        }
    
        public static RequestPredicate accept(MediaType... mediaTypes) {
            Assert.notEmpty(mediaTypes, "'mediaTypes' must not be empty");
            return new RequestPredicates.AcceptPredicate(mediaTypes);
        }
    
        public static RequestPredicate GET(String pattern) {
            return method(HttpMethod.GET).and(path(pattern));
        }
    
        public static RequestPredicate HEAD(String pattern) {
            return method(HttpMethod.HEAD).and(path(pattern));
        }
    
        public static RequestPredicate POST(String pattern) {
            return method(HttpMethod.POST).and(path(pattern));
        }
    
        public static RequestPredicate PUT(String pattern) {
            return method(HttpMethod.PUT).and(path(pattern));
        }
    
        public static RequestPredicate PATCH(String pattern) {
            return method(HttpMethod.PATCH).and(path(pattern));
        }
    
        public static RequestPredicate DELETE(String pattern) {
            return method(HttpMethod.DELETE).and(path(pattern));
        }
    
        public static RequestPredicate OPTIONS(String pattern) {
            return method(HttpMethod.OPTIONS).and(path(pattern));
        }
    
        public static RequestPredicate pathExtension(String extension) {
            Assert.notNull(extension, "'extension' must not be null");
            return new RequestPredicates.PathExtensionPredicate(extension);
        }
    
        public static RequestPredicate pathExtension(Predicate<String> extensionPredicate) {
            return new RequestPredicates.PathExtensionPredicate(extensionPredicate);
        }
    
        public static RequestPredicate queryParam(String name, String value) {
            return new RequestPredicates.QueryParamPredicate(name, value);
        }
    
        public static RequestPredicate queryParam(String name, Predicate<String> predicate) {
            return new RequestPredicates.QueryParamPredicate(name, predicate);
        }
    
        private static void traceMatch(String prefix, Object desired, @Nullable Object actual, boolean match) {
            if (logger.isTraceEnabled()) {
                logger.trace(String.format("%s \"%s\" %s against value \"%s\"", prefix, desired, match ? "matches" : "does not match", actual));
            }
    
        }
    
        private static void restoreAttributes(ServerRequest request, Map<String, Object> attributes) {
            request.attributes().clear();
            request.attributes().putAll(attributes);
        }
    
        private static Map<String, String> mergePathVariables(Map<String, String> oldVariables, Map<String, String> newVariables) {
            if (!newVariables.isEmpty()) {
                Map<String, String> mergedVariables = new LinkedHashMap(oldVariables);
                mergedVariables.putAll(newVariables);
                return mergedVariables;
            } else {
                return oldVariables;
            }
        }
    
        private static PathPattern mergePatterns(@Nullable PathPattern oldPattern, PathPattern newPattern) {
            return oldPattern != null ? oldPattern.combine(newPattern) : newPattern;
        }
    
        private static class SubPathServerRequestWrapper implements ServerRequest {
            private final ServerRequest request;
            private final PathContainer pathContainer;
            private final Map<String, Object> attributes;
    
            public SubPathServerRequestWrapper(ServerRequest request, PathRemainingMatchInfo info, PathPattern pattern) {
                this.request = request;
                this.pathContainer = new RequestPredicates.SubPathServerRequestWrapper.SubPathContainer(info.getPathRemaining());
                this.attributes = mergeAttributes(request, info.getUriVariables(), pattern);
            }
    
            private static Map<String, Object> mergeAttributes(ServerRequest request, Map<String, String> pathVariables, PathPattern pattern) {
                Map<String, Object> result = new ConcurrentHashMap(request.attributes());
                result.put(RouterFunctions.URI_TEMPLATE_VARIABLES_ATTRIBUTE, RequestPredicates.mergePathVariables(request.pathVariables(), pathVariables));
                pattern = RequestPredicates.mergePatterns((PathPattern)request.attributes().get(RouterFunctions.MATCHING_PATTERN_ATTRIBUTE), pattern);
                result.put(RouterFunctions.MATCHING_PATTERN_ATTRIBUTE, pattern);
                return result;
            }
    
            public HttpMethod method() {
                return this.request.method();
            }
    
            public String methodName() {
                return this.request.methodName();
            }
    
            public URI uri() {
                return this.request.uri();
            }
    
            public UriBuilder uriBuilder() {
                return this.request.uriBuilder();
            }
    
            public String path() {
                return this.pathContainer.value();
            }
    
            public PathContainer pathContainer() {
                return this.pathContainer;
            }
    
            public Headers headers() {
                return this.request.headers();
            }
    
            public MultiValueMap<String, HttpCookie> cookies() {
                return this.request.cookies();
            }
    
            public Optional<InetSocketAddress> remoteAddress() {
                return this.request.remoteAddress();
            }
    
            public Optional<InetSocketAddress> localAddress() {
                return this.request.localAddress();
            }
    
            public List<HttpMessageReader<?>> messageReaders() {
                return this.request.messageReaders();
            }
    
            public <T> T body(BodyExtractor<T, ? super ServerHttpRequest> extractor) {
                return this.request.body(extractor);
            }
    
            public <T> T body(BodyExtractor<T, ? super ServerHttpRequest> extractor, Map<String, Object> hints) {
                return this.request.body(extractor, hints);
            }
    
            public <T> Mono<T> bodyToMono(Class<? extends T> elementClass) {
                return this.request.bodyToMono(elementClass);
            }
    
            public <T> Mono<T> bodyToMono(ParameterizedTypeReference<T> typeReference) {
                return this.request.bodyToMono(typeReference);
            }
    
            public <T> Flux<T> bodyToFlux(Class<? extends T> elementClass) {
                return this.request.bodyToFlux(elementClass);
            }
    
            public <T> Flux<T> bodyToFlux(ParameterizedTypeReference<T> typeReference) {
                return this.request.bodyToFlux(typeReference);
            }
    
            public Map<String, Object> attributes() {
                return this.attributes;
            }
    
            public Optional<String> queryParam(String name) {
                return this.request.queryParam(name);
            }
    
            public MultiValueMap<String, String> queryParams() {
                return this.request.queryParams();
            }
    
            public Map<String, String> pathVariables() {
                return (Map)this.attributes.getOrDefault(RouterFunctions.URI_TEMPLATE_VARIABLES_ATTRIBUTE, Collections.emptyMap());
            }
    
            public Mono<WebSession> session() {
                return this.request.session();
            }
    
            public Mono<? extends Principal> principal() {
                return this.request.principal();
            }
    
            public Mono<MultiValueMap<String, String>> formData() {
                return this.request.formData();
            }
    
            public Mono<MultiValueMap<String, Part>> multipartData() {
                return this.request.multipartData();
            }
    
            public ServerWebExchange exchange() {
                return this.request.exchange();
            }
    
            public String toString() {
                return this.method() + " " + this.path();
            }
    
            private static class SubPathContainer implements PathContainer {
                private static final Separator SEPARATOR = () -> {
                    return "/";
                };
                private final String value;
                private final List<Element> elements;
    
                public SubPathContainer(PathContainer original) {
                    this.value = prefixWithSlash(original.value());
                    this.elements = prependWithSeparator(original.elements());
                }
    
                private static String prefixWithSlash(String path) {
                    if (!path.startsWith("/")) {
                        path = "/" + path;
                    }
    
                    return path;
                }
    
                private static List<Element> prependWithSeparator(List<Element> elements) {
                    List<Element> result = new ArrayList(elements);
                    if (result.isEmpty() || !(result.get(0) instanceof Separator)) {
                        result.add(0, SEPARATOR);
                    }
    
                    return Collections.unmodifiableList(result);
                }
    
                public String value() {
                    return this.value;
                }
    
                public List<Element> elements() {
                    return this.elements;
                }
            }
        }
    
        static class OrRequestPredicate implements RequestPredicate {
            private final RequestPredicate left;
            private final RequestPredicate right;
    
            public OrRequestPredicate(RequestPredicate left, RequestPredicate right) {
                Assert.notNull(left, "Left RequestPredicate must not be null");
                Assert.notNull(right, "Right RequestPredicate must not be null");
                this.left = left;
                this.right = right;
            }
    
            public boolean test(ServerRequest request) {
                Map<String, Object> oldAttributes = new HashMap(request.attributes());
                if (this.left.test(request)) {
                    return true;
                } else {
                    RequestPredicates.restoreAttributes(request, oldAttributes);
                    if (this.right.test(request)) {
                        return true;
                    } else {
                        RequestPredicates.restoreAttributes(request, oldAttributes);
                        return false;
                    }
                }
            }
    
            public Optional<ServerRequest> nest(ServerRequest request) {
                Optional<ServerRequest> leftResult = this.left.nest(request);
                return leftResult.isPresent() ? leftResult : this.right.nest(request);
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.startOr();
                this.left.accept(visitor);
                visitor.or();
                this.right.accept(visitor);
                visitor.endOr();
            }
    
            public String toString() {
                return String.format("(%s || %s)", this.left, this.right);
            }
        }
    
        static class NegateRequestPredicate implements RequestPredicate {
            private final RequestPredicate delegate;
    
            public NegateRequestPredicate(RequestPredicate delegate) {
                Assert.notNull(delegate, "Delegate must not be null");
                this.delegate = delegate;
            }
    
            public boolean test(ServerRequest request) {
                Map<String, Object> oldAttributes = new HashMap(request.attributes());
                boolean result = !this.delegate.test(request);
                if (!result) {
                    RequestPredicates.restoreAttributes(request, oldAttributes);
                }
    
                return result;
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.startNegate();
                this.delegate.accept(visitor);
                visitor.endNegate();
            }
    
            public String toString() {
                return "!" + this.delegate.toString();
            }
        }
    
        static class AndRequestPredicate implements RequestPredicate {
            private final RequestPredicate left;
            private final RequestPredicate right;
    
            public AndRequestPredicate(RequestPredicate left, RequestPredicate right) {
                Assert.notNull(left, "Left RequestPredicate must not be null");
                Assert.notNull(right, "Right RequestPredicate must not be null");
                this.left = left;
                this.right = right;
            }
    
            public boolean test(ServerRequest request) {
                Map<String, Object> oldAttributes = new HashMap(request.attributes());
                if (this.left.test(request) && this.right.test(request)) {
                    return true;
                } else {
                    RequestPredicates.restoreAttributes(request, oldAttributes);
                    return false;
                }
            }
    
            public Optional<ServerRequest> nest(ServerRequest request) {
                Optional var10000 = this.left.nest(request);
                RequestPredicate var10001 = this.right;
                var10001.getClass();
                return var10000.flatMap(var10001::nest);
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.startAnd();
                this.left.accept(visitor);
                visitor.and();
                this.right.accept(visitor);
                visitor.endAnd();
            }
    
            public String toString() {
                return String.format("(%s && %s)", this.left, this.right);
            }
        }
    
        private static class QueryParamPredicate implements RequestPredicate {
            private final String name;
            private final Predicate<String> valuePredicate;
            @Nullable
            private final String value;
    
            public QueryParamPredicate(String name, Predicate<String> valuePredicate) {
                Assert.notNull(name, "Name must not be null");
                Assert.notNull(valuePredicate, "Predicate must not be null");
                this.name = name;
                this.valuePredicate = valuePredicate;
                this.value = null;
            }
    
            public QueryParamPredicate(String name, String value) {
                Assert.notNull(name, "Name must not be null");
                Assert.notNull(value, "Value must not be null");
                this.name = name;
                this.valuePredicate = value::equals;
                this.value = value;
            }
    
            public boolean test(ServerRequest request) {
                Optional<String> s = request.queryParam(this.name);
                return s.filter(this.valuePredicate).isPresent();
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.queryParam(this.name, this.value != null ? this.value : this.valuePredicate.toString());
            }
    
            public String toString() {
                return String.format("?%s %s", this.name, this.value != null ? this.value : this.valuePredicate);
            }
        }
    
        private static class PathExtensionPredicate implements RequestPredicate {
            private final Predicate<String> extensionPredicate;
            @Nullable
            private final String extension;
    
            public PathExtensionPredicate(Predicate<String> extensionPredicate) {
                Assert.notNull(extensionPredicate, "Predicate must not be null");
                this.extensionPredicate = extensionPredicate;
                this.extension = null;
            }
    
            public PathExtensionPredicate(String extension) {
                Assert.notNull(extension, "Extension must not be null");
                this.extensionPredicate = (s) -> {
                    boolean match = extension.equalsIgnoreCase(s);
                    RequestPredicates.traceMatch("Extension", extension, s, match);
                    return match;
                };
                this.extension = extension;
            }
    
            public boolean test(ServerRequest request) {
                String pathExtension = UriUtils.extractFileExtension(request.path());
                return this.extensionPredicate.test(pathExtension);
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.pathExtension(this.extension != null ? this.extension : this.extensionPredicate.toString());
            }
    
            public String toString() {
                return String.format("*.%s", this.extension != null ? this.extension : this.extensionPredicate);
            }
        }
    
        private static class AcceptPredicate extends RequestPredicates.HeadersPredicate {
            private final Set<MediaType> mediaTypes;
    
            public AcceptPredicate(MediaType... mediaTypes) {
                this((Set)(new HashSet(Arrays.asList(mediaTypes))));
            }
    
            private AcceptPredicate(Set<MediaType> mediaTypes) {
                super((headers) -> {
                    List<MediaType> acceptedMediaTypes = acceptedMediaTypes(headers);
                    boolean match = acceptedMediaTypes.stream().anyMatch((acceptedMediaType) -> {
                        Stream var10000 = mediaTypes.stream();
                        acceptedMediaType.getClass();
                        return var10000.anyMatch(acceptedMediaType::isCompatibleWith);
                    });
                    RequestPredicates.traceMatch("Accept", mediaTypes, acceptedMediaTypes, match);
                    return match;
                });
                this.mediaTypes = mediaTypes;
            }
    
            @NonNull
            private static List<MediaType> acceptedMediaTypes(Headers headers) {
                List<MediaType> acceptedMediaTypes = headers.accept();
                if (acceptedMediaTypes.isEmpty()) {
                    acceptedMediaTypes = Collections.singletonList(MediaType.ALL);
                } else {
                    MediaType.sortBySpecificityAndQuality(acceptedMediaTypes);
                }
    
                return acceptedMediaTypes;
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.header("Accept", this.mediaTypes.size() == 1 ? ((MediaType)this.mediaTypes.iterator().next()).toString() : this.mediaTypes.toString());
            }
    
            public String toString() {
                return String.format("Accept: %s", this.mediaTypes.size() == 1 ? ((MediaType)this.mediaTypes.iterator().next()).toString() : this.mediaTypes.toString());
            }
        }
    
        private static class ContentTypePredicate extends RequestPredicates.HeadersPredicate {
            private final Set<MediaType> mediaTypes;
    
            public ContentTypePredicate(MediaType... mediaTypes) {
                this((Set)(new HashSet(Arrays.asList(mediaTypes))));
            }
    
            private ContentTypePredicate(Set<MediaType> mediaTypes) {
                super((headers) -> {
                    MediaType contentType = (MediaType)headers.contentType().orElse(MediaType.APPLICATION_OCTET_STREAM);
                    boolean match = mediaTypes.stream().anyMatch((mediaType) -> {
                        return mediaType.includes(contentType);
                    });
                    RequestPredicates.traceMatch("Content-Type", mediaTypes, contentType, match);
                    return match;
                });
                this.mediaTypes = mediaTypes;
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.header("Content-Type", this.mediaTypes.size() == 1 ? ((MediaType)this.mediaTypes.iterator().next()).toString() : this.mediaTypes.toString());
            }
    
            public String toString() {
                return String.format("Content-Type: %s", this.mediaTypes.size() == 1 ? ((MediaType)this.mediaTypes.iterator().next()).toString() : this.mediaTypes.toString());
            }
        }
    
        private static class HeadersPredicate implements RequestPredicate {
            private final Predicate<Headers> headersPredicate;
    
            public HeadersPredicate(Predicate<Headers> headersPredicate) {
                Assert.notNull(headersPredicate, "Predicate must not be null");
                this.headersPredicate = headersPredicate;
            }
    
            public boolean test(ServerRequest request) {
                return CorsUtils.isPreFlightRequest(request.exchange().getRequest()) ? true : this.headersPredicate.test(request.headers());
            }
    
            public String toString() {
                return this.headersPredicate.toString();
            }
        }
    
        private static class PathPatternPredicate implements RequestPredicate {
            private final PathPattern pattern;
    
            public PathPatternPredicate(PathPattern pattern) {
                Assert.notNull(pattern, "'pattern' must not be null");
                this.pattern = pattern;
            }
    
            public boolean test(ServerRequest request) {
                PathContainer pathContainer = request.pathContainer();
                PathMatchInfo info = this.pattern.matchAndExtract(pathContainer);
                RequestPredicates.traceMatch("Pattern", this.pattern.getPatternString(), request.path(), info != null);
                if (info != null) {
                    mergeAttributes(request, info.getUriVariables(), this.pattern);
                    return true;
                } else {
                    return false;
                }
            }
    
            private static void mergeAttributes(ServerRequest request, Map<String, String> variables, PathPattern pattern) {
                Map<String, String> pathVariables = RequestPredicates.mergePathVariables(request.pathVariables(), variables);
                request.attributes().put(RouterFunctions.URI_TEMPLATE_VARIABLES_ATTRIBUTE, Collections.unmodifiableMap(pathVariables));
                pattern = RequestPredicates.mergePatterns((PathPattern)request.attributes().get(RouterFunctions.MATCHING_PATTERN_ATTRIBUTE), pattern);
                request.attributes().put(RouterFunctions.MATCHING_PATTERN_ATTRIBUTE, pattern);
            }
    
            public Optional<ServerRequest> nest(ServerRequest request) {
                return Optional.ofNullable(this.pattern.matchStartOfPath(request.pathContainer())).map((info) -> {
                    return new RequestPredicates.SubPathServerRequestWrapper(request, info, this.pattern);
                });
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.path(this.pattern.getPatternString());
            }
    
            public String toString() {
                return this.pattern.getPatternString();
            }
        }
    
        private static class HttpMethodPredicate implements RequestPredicate {
            private final Set<HttpMethod> httpMethods;
    
            public HttpMethodPredicate(HttpMethod httpMethod) {
                Assert.notNull(httpMethod, "HttpMethod must not be null");
                this.httpMethods = EnumSet.of(httpMethod);
            }
    
            public HttpMethodPredicate(HttpMethod... httpMethods) {
                Assert.notEmpty(httpMethods, "HttpMethods must not be empty");
                this.httpMethods = EnumSet.copyOf(Arrays.asList(httpMethods));
            }
    
            public boolean test(ServerRequest request) {
                HttpMethod method = method(request);
                boolean match = this.httpMethods.contains(method);
                RequestPredicates.traceMatch("Method", this.httpMethods, method, match);
                return match;
            }
    
            @Nullable
            private static HttpMethod method(ServerRequest request) {
                if (CorsUtils.isPreFlightRequest(request.exchange().getRequest())) {
                    String accessControlRequestMethod = request.headers().firstHeader("Access-Control-Request-Method");
                    return HttpMethod.resolve(accessControlRequestMethod);
                } else {
                    return request.method();
                }
            }
    
            public void accept(RequestPredicates.Visitor visitor) {
                visitor.method(Collections.unmodifiableSet(this.httpMethods));
            }
    
            public String toString() {
                return this.httpMethods.size() == 1 ? ((HttpMethod)this.httpMethods.iterator().next()).toString() : this.httpMethods.toString();
            }
        }
    
        public interface Visitor {
            void method(Set<HttpMethod> var1);
    
            void path(String var1);
            void pathExtension(String var1);
    
            void header(String var1, String var2);
            void queryParam(String var1, String var2);
    
            void startAnd();
            void and();
            void endAnd();
    
            void startOr();
            void or();
            void endOr();
    
            void startNegate();
            void endNegate();
    
            void unknown(RequestPredicate var1);
        }
    }

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

**HandlerFunction**

@FunctionalInterface
    public interface HandlerFunction<T extends ServerResponse> {
        Mono<T> handle(ServerRequest var1);
    }

**ServerRequest**

public interface ServerRequest {
        @Nullable
        default HttpMethod method() {
            return HttpMethod.resolve(this.methodName());
        }
    
        String methodName();
    
        URI uri();
        UriBuilder uriBuilder();
    
        default String path() {
            return this.uri().getRawPath();
        }
    
        default PathContainer pathContainer() {
            return PathContainer.parsePath(this.path());
        }
    
        ServerRequest.Headers headers();
    
        MultiValueMap<String, HttpCookie> cookies();
    
        Optional<InetSocketAddress> remoteAddress();
        Optional<InetSocketAddress> localAddress();
    
        List<HttpMessageReader<?>> messageReaders();
    
        <T> T body(BodyExtractor<T, ? super ServerHttpRequest> var1);
        <T> T body(BodyExtractor<T, ? super ServerHttpRequest> var1, Map<String, Object> var2);
    
        <T> Mono<T> bodyToMono(Class<? extends T> var1);
        <T> Mono<T> bodyToMono(ParameterizedTypeReference<T> var1);
    
        <T> Flux<T> bodyToFlux(Class<? extends T> var1);
        <T> Flux<T> bodyToFlux(ParameterizedTypeReference<T> var1);
    
        default Optional<Object> attribute(String name) {
            return Optional.ofNullable(this.attributes().get(name));
        }
    
        Map<String, Object> attributes();
    
        default Optional<String> queryParam(String name) {
            List<String> queryParamValues = (List)this.queryParams().get(name);
            if (CollectionUtils.isEmpty(queryParamValues)) {
                return Optional.empty();
            } else {
                String value = (String)queryParamValues.get(0);
                if (value == null) {
                    value = "";
                }
    
                return Optional.of(value);
            }
        }
    
        MultiValueMap<String, String> queryParams();
    
        default String pathVariable(String name) {
            Map<String, String> pathVariables = this.pathVariables();
            if (pathVariables.containsKey(name)) {
                return (String)this.pathVariables().get(name);
            } else {
                throw new IllegalArgumentException("No path variable with name \"" + name + "\" available");
            }
        }
    
        Map<String, String> pathVariables();
    
        Mono<WebSession> session();
    
        Mono<? extends Principal> principal();
    
        Mono<MultiValueMap<String, String>> formData();
        Mono<MultiValueMap<String, Part>> multipartData();
    
        ServerWebExchange exchange();
    
        default Mono<ServerResponse> checkNotModified(Instant lastModified) {
            Assert.notNull(lastModified, "LastModified must not be null");
            return DefaultServerRequest.checkNotModified(this.exchange(), lastModified, (String)null);
        }
    
        default Mono<ServerResponse> checkNotModified(String etag) {
            Assert.notNull(etag, "Etag must not be null");
            return DefaultServerRequest.checkNotModified(this.exchange(), (Instant)null, etag);
        }
    
        default Mono<ServerResponse> checkNotModified(Instant lastModified, String etag) {
            Assert.notNull(lastModified, "LastModified must not be null");
            Assert.notNull(etag, "Etag must not be null");
            return DefaultServerRequest.checkNotModified(this.exchange(), lastModified, etag);
        }
    
        static ServerRequest create(ServerWebExchange exchange, List<HttpMessageReader<?>> messageReaders) {
            return new DefaultServerRequest(exchange, messageReaders);
        }
    
        static ServerRequest.Builder from(ServerRequest other) {
            return new DefaultServerRequestBuilder(other);
        }
    
        public interface Builder {
            ServerRequest.Builder method(HttpMethod var1);
    
            ServerRequest.Builder uri(URI var1);
    
            ServerRequest.Builder header(String var1, String... var2);
            ServerRequest.Builder headers(Consumer<HttpHeaders> var1);
    
            ServerRequest.Builder cookie(String var1, String... var2);
            ServerRequest.Builder cookies(Consumer<MultiValueMap<String, HttpCookie>> var1);
    
            ServerRequest.Builder body(Flux<DataBuffer> var1);
            ServerRequest.Builder body(String var1);
    
            ServerRequest.Builder attribute(String var1, Object var2);
            ServerRequest.Builder attributes(Consumer<Map<String, Object>> var1);
    
            ServerRequest build();
        }
    
        public interface Headers {
            List<MediaType> accept();
            List<Charset> acceptCharset();
            List<LanguageRange> acceptLanguage();
    
            OptionalLong contentLength();
            Optional<MediaType> contentType();
    
            @Nullable
            InetSocketAddress host();
    
            List<HttpRange> range();
    
            List<String> header(String var1);
    
            @Nullable
            default String firstHeader(String headerName) {
                List<String> list = this.header(headerName);
                return list.isEmpty() ? null : (String)list.get(0);
            }
    
            HttpHeaders asHttpHeaders();
        }
    }

**ServerResponse**

public interface ServerResponse {
        HttpStatus statusCode();
    
        int rawStatusCode();
    
        HttpHeaders headers();
    
        MultiValueMap<String, ResponseCookie> cookies();
    
        Mono<Void> writeTo(ServerWebExchange var1, ServerResponse.Context var2);
    
        static ServerResponse.BodyBuilder from(ServerResponse other) {
            return new DefaultServerResponseBuilder(other);
        }
    
        static ServerResponse.BodyBuilder status(HttpStatus status) {
            return new DefaultServerResponseBuilder(status);
        }
    
        static ServerResponse.BodyBuilder status(int status) {
            return new DefaultServerResponseBuilder(status);
        }
    
        static ServerResponse.BodyBuilder ok() {
            return status(HttpStatus.OK);
        }
    
        static ServerResponse.BodyBuilder created(URI location) {
            ServerResponse.BodyBuilder builder = status(HttpStatus.CREATED);
            return (ServerResponse.BodyBuilder)builder.location(location);
        }
    
        static ServerResponse.BodyBuilder accepted() {
            return status(HttpStatus.ACCEPTED);
        }
    
        static ServerResponse.HeadersBuilder<?> noContent() {
            return status(HttpStatus.NO_CONTENT);
        }
    
        static ServerResponse.BodyBuilder seeOther(URI location) {
            ServerResponse.BodyBuilder builder = status(HttpStatus.SEE_OTHER);
            return (ServerResponse.BodyBuilder)builder.location(location);
        }
    
        static ServerResponse.BodyBuilder temporaryRedirect(URI location) {
            ServerResponse.BodyBuilder builder = status(HttpStatus.TEMPORARY_REDIRECT);
            return (ServerResponse.BodyBuilder)builder.location(location);
        }
    
        static ServerResponse.BodyBuilder permanentRedirect(URI location) {
            ServerResponse.BodyBuilder builder = status(HttpStatus.PERMANENT_REDIRECT);
            return (ServerResponse.BodyBuilder)builder.location(location);
        }
    
        static ServerResponse.BodyBuilder badRequest() {
            return status(HttpStatus.BAD_REQUEST);
        }
    
        static ServerResponse.HeadersBuilder<?> notFound() {
            return status(HttpStatus.NOT_FOUND);
        }
    
        static ServerResponse.BodyBuilder unprocessableEntity() {
            return status(HttpStatus.UNPROCESSABLE_ENTITY);
        }
    
        public interface Context {
            List<HttpMessageWriter<?>> messageWriters();
    
            List<ViewResolver> viewResolvers();
        }
    
        public interface BodyBuilder extends ServerResponse.HeadersBuilder<ServerResponse.BodyBuilder> {
            ServerResponse.BodyBuilder contentLength(long var1);
            ServerResponse.BodyBuilder contentType(MediaType var1);
    
            ServerResponse.BodyBuilder hint(String var1, Object var2);
            ServerResponse.BodyBuilder hints(Consumer<Map<String, Object>> var1);
    
            Mono<ServerResponse> bodyValue(Object var1);
    
            <T, P extends Publisher<T>> Mono<ServerResponse> body(P var1, Class<T> var2);
            <T, P extends Publisher<T>> Mono<ServerResponse> body(P var1, ParameterizedTypeReference<T> var2);
    
            Mono<ServerResponse> body(Object var1, Class<?> var2);
            Mono<ServerResponse> body(Object var1, ParameterizedTypeReference<?> var2);
            Mono<ServerResponse> body(BodyInserter<?, ? super ServerHttpResponse> var1);
    
            /** @deprecated */
            @Deprecated
            Mono<ServerResponse> syncBody(Object var1);
    
            Mono<ServerResponse> render(String var1, Object... var2);
            Mono<ServerResponse> render(String var1, Map<String, ?> var2);
        }
    
        public interface HeadersBuilder<B extends ServerResponse.HeadersBuilder<B>> {
            B header(String var1, String... var2);
            B headers(Consumer<HttpHeaders> var1);
    
            B cookie(ResponseCookie var1);
            B cookies(Consumer<MultiValueMap<String, ResponseCookie>> var1);
    
            B allow(HttpMethod... var1);
            B allow(Set<HttpMethod> var1);
    
            B eTag(String var1);
    
            B lastModified(ZonedDateTime var1);
            B lastModified(Instant var1);
    
            B location(URI var1);
    
            B cacheControl(CacheControl var1);
    
            B varyBy(String... var1);
    
            Mono<ServerResponse> build();
            Mono<ServerResponse> build(Publisher<Void> var1);
            Mono<ServerResponse> build(BiFunction<ServerWebExchange, ServerResponse.Context, Mono<Void>> var1);
        }
    }

[https_docs.spring.io_spring-boot_docs_2.3.0.RELEASE_reference_html_spring-boot-features.html_boot-features-webflux]: https://docs.spring.io/spring-boot/docs/2.3.0.RELEASE/reference/html/spring-boot-features.html#boot-features-webflux
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