Java tutorial
/* * Copyright 2002-2018 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * 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.http; import java.lang.reflect.Type; import java.net.URI; import java.nio.charset.Charset; import java.time.Instant; import java.time.ZonedDateTime; import java.util.Arrays; import org.springframework.lang.Nullable; import org.springframework.util.MultiValueMap; import org.springframework.util.ObjectUtils; /** * Extension of {@link HttpEntity} that adds a {@linkplain HttpMethod method} and * {@linkplain URI uri}. Used in {@code RestTemplate} and {@code @Controller} methods. * * <p>In {@code RestTemplate}, this class is used as parameter in * {@link org.springframework.web.client.RestTemplate#exchange(RequestEntity, Class) exchange()}: * <pre class="code"> * MyRequest body = ... * RequestEntity<MyRequest> request = RequestEntity * .post(new URI("https://example.com/bar")) * .accept(MediaType.APPLICATION_JSON) * .body(body); * ResponseEntity<MyResponse> response = template.exchange(request, MyResponse.class); * </pre> * * <p>If you would like to provide a URI template with variables, consider using * {@link org.springframework.web.util.UriTemplate}: * <pre class="code"> * URI uri = new UriTemplate("https://example.com/{foo}").expand("bar"); * RequestEntity<MyRequest> request = RequestEntity.post(uri).accept(MediaType.APPLICATION_JSON).body(body); * </pre> * * <p>Can also be used in Spring MVC, as a parameter in a @Controller method: * <pre class="code"> * @RequestMapping("/handle") * public void handle(RequestEntity<String> request) { * HttpMethod method = request.getMethod(); * URI url = request.getUrl(); * String body = request.getBody(); * } * </pre> * * @author Arjen Poutsma * @author Sebastien Deleuze * @since 4.1 * @param <T> the body type * @see #getMethod() * @see #getUrl() */ public class RequestEntity<T> extends HttpEntity<T> { @Nullable private final HttpMethod method; private final URI url; @Nullable private final Type type; /** * Constructor with method and URL but without body nor headers. * @param method the method * @param url the URL */ public RequestEntity(HttpMethod method, URI url) { this(null, null, method, url, null); } /** * Constructor with method, URL and body but without headers. * @param body the body * @param method the method * @param url the URL */ public RequestEntity(@Nullable T body, HttpMethod method, URI url) { this(body, null, method, url, null); } /** * Constructor with method, URL, body and type but without headers. * @param body the body * @param method the method * @param url the URL * @param type the type used for generic type resolution * @since 4.3 */ public RequestEntity(@Nullable T body, HttpMethod method, URI url, Type type) { this(body, null, method, url, type); } /** * Constructor with method, URL and headers but without body. * @param headers the headers * @param method the method * @param url the URL */ public RequestEntity(MultiValueMap<String, String> headers, HttpMethod method, URI url) { this(null, headers, method, url, null); } /** * Constructor with method, URL, headers and body. * @param body the body * @param headers the headers * @param method the method * @param url the URL */ public RequestEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, @Nullable HttpMethod method, URI url) { this(body, headers, method, url, null); } /** * Constructor with method, URL, headers, body and type. * @param body the body * @param headers the headers * @param method the method * @param url the URL * @param type the type used for generic type resolution * @since 4.3 */ public RequestEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers, @Nullable HttpMethod method, URI url, @Nullable Type type) { super(body, headers); this.method = method; this.url = url; this.type = type; } /** * Return the HTTP method of the request. * @return the HTTP method as an {@code HttpMethod} enum value */ @Nullable public HttpMethod getMethod() { return this.method; } /** * Return the URL of the request. * @return the URL as a {@code URI} */ public URI getUrl() { return this.url; } /** * Return the type of the request's body. * @return the request's body type, or {@code null} if not known * @since 4.3 */ @Nullable public Type getType() { if (this.type == null) { T body = getBody(); if (body != null) { return body.getClass(); } } return this.type; } @Override public boolean equals(@Nullable Object other) { if (this == other) { return true; } if (!super.equals(other)) { return false; } RequestEntity<?> otherEntity = (RequestEntity<?>) other; return (ObjectUtils.nullSafeEquals(getMethod(), otherEntity.getMethod()) && ObjectUtils.nullSafeEquals(getUrl(), otherEntity.getUrl())); } @Override public int hashCode() { int hashCode = super.hashCode(); hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.method); hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.url); return hashCode; } @Override public String toString() { StringBuilder builder = new StringBuilder("<"); builder.append(getMethod()); builder.append(' '); builder.append(getUrl()); builder.append(','); T body = getBody(); HttpHeaders headers = getHeaders(); if (body != null) { builder.append(body); builder.append(','); } builder.append(headers); builder.append('>'); return builder.toString(); } // Static builder methods /** * Create a builder with the given method and url. * @param method the HTTP method (GET, POST, etc) * @param url the URL * @return the created builder */ public static BodyBuilder method(HttpMethod method, URI url) { return new DefaultBodyBuilder(method, url); } /** * Create an HTTP GET builder with the given url. * @param url the URL * @return the created builder */ public static HeadersBuilder<?> get(URI url) { return method(HttpMethod.GET, url); } /** * Create an HTTP HEAD builder with the given url. * @param url the URL * @return the created builder */ public static HeadersBuilder<?> head(URI url) { return method(HttpMethod.HEAD, url); } /** * Create an HTTP POST builder with the given url. * @param url the URL * @return the created builder */ public static BodyBuilder post(URI url) { return method(HttpMethod.POST, url); } /** * Create an HTTP PUT builder with the given url. * @param url the URL * @return the created builder */ public static BodyBuilder put(URI url) { return method(HttpMethod.PUT, url); } /** * Create an HTTP PATCH builder with the given url. * @param url the URL * @return the created builder */ public static BodyBuilder patch(URI url) { return method(HttpMethod.PATCH, url); } /** * Create an HTTP DELETE builder with the given url. * @param url the URL * @return the created builder */ public static HeadersBuilder<?> delete(URI url) { return method(HttpMethod.DELETE, url); } /** * Creates an HTTP OPTIONS builder with the given url. * @param url the URL * @return the created builder */ public static HeadersBuilder<?> options(URI url) { return method(HttpMethod.OPTIONS, url); } /** * Defines a builder that adds headers to the request entity. * @param <B> the builder subclass */ public interface HeadersBuilder<B extends HeadersBuilder<B>> { /** * Add the given, single header value under the given name. * @param headerName the header name * @param headerValues the header value(s) * @return this builder * @see HttpHeaders#add(String, String) */ B header(String headerName, String... headerValues); /** * Set the list of acceptable {@linkplain MediaType media types}, as * specified by the {@code Accept} header. * @param acceptableMediaTypes the acceptable media types */ B accept(MediaType... acceptableMediaTypes); /** * Set the list of acceptable {@linkplain Charset charsets}, as specified * by the {@code Accept-Charset} header. * @param acceptableCharsets the acceptable charsets */ B acceptCharset(Charset... acceptableCharsets); /** * Set the value of the {@code If-Modified-Since} header. * @param ifModifiedSince the new value of the header * @since 5.1.4 */ B ifModifiedSince(ZonedDateTime ifModifiedSince); /** * Set the value of the {@code If-Modified-Since} header. * @param ifModifiedSince the new value of the header * @since 5.1.4 */ B ifModifiedSince(Instant ifModifiedSince); /** * Set the value of the {@code If-Modified-Since} header. * <p>The date should be specified as the number of milliseconds since * January 1, 1970 GMT. * @param ifModifiedSince the new value of the header */ B ifModifiedSince(long ifModifiedSince); /** * Set the values of the {@code If-None-Match} header. * @param ifNoneMatches the new value of the header */ B ifNoneMatch(String... ifNoneMatches); /** * Builds the request entity with no body. * @return the request entity * @see BodyBuilder#body(Object) */ RequestEntity<Void> build(); } /** * Defines a builder that adds a body to the response entity. */ public interface BodyBuilder extends HeadersBuilder<BodyBuilder> { /** * Set the length of the body in bytes, as specified by the * {@code Content-Length} header. * @param contentLength the content length * @return this builder * @see HttpHeaders#setContentLength(long) */ BodyBuilder contentLength(long contentLength); /** * Set the {@linkplain MediaType media type} of the body, as specified * by the {@code Content-Type} header. * @param contentType the content type * @return this builder * @see HttpHeaders#setContentType(MediaType) */ BodyBuilder contentType(MediaType contentType); /** * Set the body of the request entity and build the RequestEntity. * @param <T> the type of the body * @param body the body of the request entity * @return the built request entity */ <T> RequestEntity<T> body(T body); /** * Set the body and type of the request entity and build the RequestEntity. * @param <T> the type of the body * @param body the body of the request entity * @param type the type of the body, useful for generic type resolution * @return the built request entity * @since 4.3 */ <T> RequestEntity<T> body(T body, Type type); } private static class DefaultBodyBuilder implements BodyBuilder { private final HttpMethod method; private final URI url; private final HttpHeaders headers = new HttpHeaders(); public DefaultBodyBuilder(HttpMethod method, URI url) { this.method = method; this.url = url; } @Override public BodyBuilder header(String headerName, String... headerValues) { for (String headerValue : headerValues) { this.headers.add(headerName, headerValue); } return this; } @Override public BodyBuilder accept(MediaType... acceptableMediaTypes) { this.headers.setAccept(Arrays.asList(acceptableMediaTypes)); return this; } @Override public BodyBuilder acceptCharset(Charset... acceptableCharsets) { this.headers.setAcceptCharset(Arrays.asList(acceptableCharsets)); return this; } @Override public BodyBuilder contentLength(long contentLength) { this.headers.setContentLength(contentLength); return this; } @Override public BodyBuilder contentType(MediaType contentType) { this.headers.setContentType(contentType); return this; } @Override public BodyBuilder ifModifiedSince(ZonedDateTime ifModifiedSince) { this.headers.setIfModifiedSince(ifModifiedSince); return this; } @Override public BodyBuilder ifModifiedSince(Instant ifModifiedSince) { this.headers.setIfModifiedSince(ifModifiedSince); return this; } @Override public BodyBuilder ifModifiedSince(long ifModifiedSince) { this.headers.setIfModifiedSince(ifModifiedSince); return this; } @Override public BodyBuilder ifNoneMatch(String... ifNoneMatches) { this.headers.setIfNoneMatch(Arrays.asList(ifNoneMatches)); return this; } @Override public RequestEntity<Void> build() { return new RequestEntity<>(this.headers, this.method, this.url); } @Override public <T> RequestEntity<T> body(T body) { return new RequestEntity<>(body, this.headers, this.method, this.url); } @Override public <T> RequestEntity<T> body(T body, Type type) { return new RequestEntity<>(body, this.headers, this.method, this.url, type); } } }