Java tutorial
/* * Copyright 2002-2019 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.web.servlet.function; import java.io.IOException; import java.net.InetSocketAddress; import java.net.URI; import java.nio.charset.Charset; import java.security.Principal; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Optional; import java.util.OptionalLong; import java.util.function.Consumer; import javax.servlet.ServletException; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import org.springframework.core.ParameterizedTypeReference; import org.springframework.core.io.buffer.DataBuffer; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpMethod; import org.springframework.http.HttpRange; import org.springframework.http.MediaType; import org.springframework.http.converter.HttpMessageConverter; import org.springframework.http.server.PathContainer; import org.springframework.lang.Nullable; import org.springframework.util.CollectionUtils; import org.springframework.util.MultiValueMap; import org.springframework.web.util.UriBuilder; /** * Represents a server-side HTTP request, as handled by a {@code HandlerFunction}. * Access to headers and body is offered by {@link Headers} and * {@link #body(Class)}, respectively. * * @author Arjen Poutsma * @since 5.2 */ public interface ServerRequest { /** * Get the HTTP method. * @return the HTTP method as an HttpMethod enum value, or {@code null} * if not resolvable (e.g. in case of a non-standard HTTP method) */ @Nullable default HttpMethod method() { return HttpMethod.resolve(methodName()); } /** * Get the name of the HTTP method. * @return the HTTP method as a String */ String methodName(); /** * Get the request URI. */ URI uri(); /** * Get a {@code UriBuilderComponents} from the URI associated with this * {@code ServerRequest}. * * @return a URI builder */ UriBuilder uriBuilder(); /** * Get the request path. */ default String path() { return uri().getRawPath(); } /** * Get the request path as a {@code PathContainer}. */ default PathContainer pathContainer() { return PathContainer.parsePath(path()); } /** * Get the headers of this request. */ Headers headers(); /** * Get the cookies of this request. */ MultiValueMap<String, Cookie> cookies(); /** * Get the remote address to which this request is connected, if available. */ Optional<InetSocketAddress> remoteAddress(); /** * Get the readers used to convert the body of this request. */ List<HttpMessageConverter<?>> messageConverters(); /** * Extract the body as an object of the given type. * @param bodyType the type of return value * @param <T> the body type * @return the body */ <T> T body(Class<T> bodyType) throws ServletException, IOException; /** * Extract the body as an object of the given type. * @param bodyType the type of return value * @param <T> the body type * @return the body */ <T> T body(ParameterizedTypeReference<T> bodyType) throws ServletException, IOException; /** * Get the request attribute value if present. * @param name the attribute name * @return the attribute value */ default Optional<Object> attribute(String name) { Map<String, Object> attributes = attributes(); if (attributes.containsKey(name)) { return Optional.of(attributes.get(name)); } else { return Optional.empty(); } } /** * Get a mutable map of request attributes. * @return the request attributes */ Map<String, Object> attributes(); /** * Get the first parameter with the given name, if present. * @param name the parameter name * @return the parameter value * @see HttpServletRequest#getParameter(String) */ default Optional<String> param(String name) { List<String> paramValues = params().get(name); if (CollectionUtils.isEmpty(paramValues)) { return Optional.empty(); } else { String value = paramValues.get(0); if (value == null) { value = ""; } return Optional.of(value); } } /** * Get all parameters for this request. * @see HttpServletRequest#getParameterMap() */ MultiValueMap<String, String> params(); /** * Get the path variable with the given name, if present. * @param name the variable name * @return the variable value * @throws IllegalArgumentException if there is no path variable with the given name */ default String pathVariable(String name) { Map<String, String> pathVariables = pathVariables(); if (pathVariables.containsKey(name)) { return pathVariables().get(name); } else { throw new IllegalArgumentException("No path variable with name \"" + name + "\" available"); } } /** * Get all path variables for this request. */ Map<String, String> pathVariables(); /** * Get the web session for this request. Always guaranteed to * return an instance either matching to the session id requested by the * client, or with a new session id either because the client did not * specify one or because the underlying session had expired. Use of this * method does not automatically create a session. */ HttpSession session(); /** * Get the authenticated user for the request, if any. */ Optional<Principal> principal(); /** * Get the servlet request that this request is based on. */ HttpServletRequest servletRequest(); // Static methods /** * Create a new {@code ServerRequest} based on the given {@code HttpServletRequest} and * message converters. * @param servletRequest the request * @param messageReaders the message readers * @return the created {@code ServerRequest} */ static ServerRequest create(HttpServletRequest servletRequest, List<HttpMessageConverter<?>> messageReaders) { return new DefaultServerRequest(servletRequest, messageReaders); } /** * Create a builder with the status, headers, and cookies of the given request. * @param other the response to copy the status, headers, and cookies from * @return the created builder */ static Builder from(ServerRequest other) { return new DefaultServerRequestBuilder(other); } /** * Represents the headers of the HTTP request. * @see ServerRequest#headers() */ interface Headers { /** * Get the list of acceptable media types, as specified by the {@code Accept} * header. * <p>Returns an empty list if the acceptable media types are unspecified. */ List<MediaType> accept(); /** * Get the list of acceptable charsets, as specified by the * {@code Accept-Charset} header. */ List<Charset> acceptCharset(); /** * Get the list of acceptable languages, as specified by the * {@code Accept-Language} header. */ List<Locale.LanguageRange> acceptLanguage(); /** * Get the length of the body in bytes, as specified by the * {@code Content-Length} header. */ OptionalLong contentLength(); /** * Get the media type of the body, as specified by the * {@code Content-Type} header. */ Optional<MediaType> contentType(); /** * Get the value of the {@code Host} header, if available. * <p>If the header value does not contain a port, the * {@linkplain InetSocketAddress#getPort() port} in the returned address will * be {@code 0}. */ @Nullable InetSocketAddress host(); /** * Get the value of the {@code Range} header. * <p>Returns an empty list when the range is unknown. */ List<HttpRange> range(); /** * Get the header value(s), if any, for the header of the given name. * <p>Returns an empty list if no header values are found. * @param headerName the header name */ List<String> header(String headerName); /** * Get the headers as an instance of {@link HttpHeaders}. */ HttpHeaders asHttpHeaders(); } /** * Defines a builder for a request. */ interface Builder { /** * Set the method of the request. * @param method the new method * @return this builder */ Builder method(HttpMethod method); /** * Set the URI of the request. * @param uri the new URI * @return this builder */ Builder uri(URI uri); /** * Add the given header value(s) under the given name. * @param headerName the header name * @param headerValues the header value(s) * @return this builder * @see HttpHeaders#add(String, String) */ Builder header(String headerName, String... headerValues); /** * Manipulate this request's headers with the given consumer. * <p>The headers provided to the consumer are "live", so that the consumer can be used to * {@linkplain HttpHeaders#set(String, String) overwrite} existing header values, * {@linkplain HttpHeaders#remove(Object) remove} values, or use any of the other * {@link HttpHeaders} methods. * @param headersConsumer a function that consumes the {@code HttpHeaders} * @return this builder */ Builder headers(Consumer<HttpHeaders> headersConsumer); /** * Add a cookie with the given name and value(s). * @param name the cookie name * @param values the cookie value(s) * @return this builder */ Builder cookie(String name, String... values); /** * Manipulate this request's cookies with the given consumer. * <p>The map provided to the consumer is "live", so that the consumer can be used to * {@linkplain MultiValueMap#set(Object, Object) overwrite} existing cookies, * {@linkplain MultiValueMap#remove(Object) remove} cookies, or use any of the other * {@link MultiValueMap} methods. * @param cookiesConsumer a function that consumes the cookies map * @return this builder */ Builder cookies(Consumer<MultiValueMap<String, Cookie>> cookiesConsumer); /** * Set the body of the request. * <p>Calling this methods will * {@linkplain org.springframework.core.io.buffer.DataBufferUtils#release(DataBuffer) release} * the existing body of the builder. * @param body the new body * @return this builder */ Builder body(byte[] body); /** * Set the body of the request to the UTF-8 encoded bytes of the given string. * <p>Calling this methods will * {@linkplain org.springframework.core.io.buffer.DataBufferUtils#release(DataBuffer) release} * the existing body of the builder. * @param body the new body * @return this builder */ Builder body(String body); /** * Add an attribute with the given name and value. * @param name the attribute name * @param value the attribute value * @return this builder */ Builder attribute(String name, Object value); /** * Manipulate this request's attributes with the given consumer. * <p>The map provided to the consumer is "live", so that the consumer can be used * to {@linkplain Map#put(Object, Object) overwrite} existing attributes, * {@linkplain Map#remove(Object) remove} attributes, or use any of the other * {@link Map} methods. * @param attributesConsumer a function that consumes the attributes map * @return this builder */ Builder attributes(Consumer<Map<String, Object>> attributesConsumer); /** * Build the request. * @return the built request */ ServerRequest build(); } }