Java tutorial
package your.microservice.core.util; /* * Copyright 2002-2014 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 * * http://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. */ import org.springframework.util.Assert; import org.springframework.util.StringUtils; import org.springframework.web.context.request.RequestAttributes; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import org.springframework.web.util.UriComponentsBuilder; import org.springframework.web.util.UrlPathHelper; import org.springframework.web.util.WebUtils; import javax.servlet.http.HttpServletRequest; /** * A UriComponentsBuilder that extracts information from an HttpServletRequest. * * @author Rossen Stoyanchev * @since 3.1 */ public class YourServletUriComponentsBuilder extends UriComponentsBuilder { private String servletRequestURI; /** * Default constructor. Protected to prevent direct instantiation. * * @see #fromContextPath(HttpServletRequest) * @see #fromServletMapping(HttpServletRequest) * @see #fromRequest(HttpServletRequest) * @see #fromCurrentContextPath() * @see #fromCurrentServletMapping() * @see #fromCurrentRequest() */ protected YourServletUriComponentsBuilder() { } /** * Prepare a builder from the host, port, scheme, and context path of * an HttpServletRequest. * @param request request to build path from * @return the component builder created from the path */ public static YourServletUriComponentsBuilder fromContextPath(HttpServletRequest request) { YourServletUriComponentsBuilder builder = fromRequest(request); builder.replacePath(request.getContextPath()); builder.replaceQuery(null); return builder; } /** * Prepare a builder from the host, port, scheme, context path, and * servlet mapping of an HttpServletRequest. The results may vary depending * on the type of servlet mapping used. * * <p>If the servlet is mapped by name, e.g. {@code "/main/*"}, the path * will end with "/main". If the servlet is mapped otherwise, e.g. * {@code "/"} or {@code "*.do"}, the result will be the same as * if calling {@link #fromContextPath(HttpServletRequest)}. * @param request request to build path from * @return a URI component builder */ public static YourServletUriComponentsBuilder fromServletMapping(HttpServletRequest request) { YourServletUriComponentsBuilder builder = fromContextPath(request); if (StringUtils.hasText(new UrlPathHelper().getPathWithinServletMapping(request))) { builder.path(request.getServletPath()); } return builder; } /** * Prepare a builder from the host, port, scheme, and path of * an HttpServletRequest. * @param request to build path from * @return a URI component builder */ public static YourServletUriComponentsBuilder fromRequestUri(HttpServletRequest request) { YourServletUriComponentsBuilder builder = fromRequest(request); builder.pathFromRequest(request); builder.replaceQuery(null); return builder; } /** * Prepare a builder by copying the scheme, host, port, path, and * query string of an HttpServletRequest. * @param request to build path from * @return a URI component builder */ public static YourServletUriComponentsBuilder fromRequest(HttpServletRequest request) { String scheme = request.getScheme(); String host = request.getServerName(); int port = request.getServerPort(); String hostHeader = request.getHeader("X-Forwarded-Host"); if (StringUtils.hasText(hostHeader)) { String[] hosts = StringUtils.commaDelimitedListToStringArray(hostHeader); String hostToUse = hosts[0]; if (hostToUse.contains(":")) { String[] hostAndPort = StringUtils.split(hostToUse, ":"); host = hostAndPort[0]; port = Integer.parseInt(hostAndPort[1]); } else { host = hostToUse; port = -1; } } String portHeader = request.getHeader("X-Forwarded-Port"); if (StringUtils.hasText(portHeader)) { port = Integer.parseInt(portHeader); } String protocolHeader = request.getHeader("X-Forwarded-Proto"); if (StringUtils.hasText(protocolHeader)) { scheme = protocolHeader; } YourServletUriComponentsBuilder builder = new YourServletUriComponentsBuilder(); builder.scheme(scheme); builder.host(host); if (scheme.equals("http") && port != 80 || scheme.equals("https") && port != 443) { builder.port(port); } builder.pathFromRequest(request); builder.query(request.getQueryString()); return builder; } /** * Same as {@link #fromContextPath(HttpServletRequest)} except the * request is obtained through {@link RequestContextHolder}. * @return a URI component builder */ public static YourServletUriComponentsBuilder fromCurrentContextPath() { return fromContextPath(getCurrentRequest()); } /** * Same as {@link #fromServletMapping(HttpServletRequest)} except the * request is obtained through {@link RequestContextHolder}. * @return a URI component builder */ public static YourServletUriComponentsBuilder fromCurrentServletMapping() { return fromServletMapping(getCurrentRequest()); } /** * Same as {@link #fromRequestUri(HttpServletRequest)} except the * request is obtained through {@link RequestContextHolder}. * @return a URI component builder */ public static YourServletUriComponentsBuilder fromCurrentRequestUri() { return fromRequestUri(getCurrentRequest()); } /** * Same as {@link #fromRequest(HttpServletRequest)} except the * request is obtained through {@link RequestContextHolder}. * @return a URI component builder */ public static YourServletUriComponentsBuilder fromCurrentRequest() { return fromRequest(getCurrentRequest()); } /** * Obtain the request through {@link RequestContextHolder}. * @return the active servlet request */ protected static HttpServletRequest getCurrentRequest() { RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes(); Assert.state(requestAttributes != null, "Could not find current request via RequestContextHolder"); Assert.isInstanceOf(ServletRequestAttributes.class, requestAttributes); HttpServletRequest servletRequest = ((ServletRequestAttributes) requestAttributes).getRequest(); Assert.state(servletRequest != null, "Could not find current HttpServletRequest"); return servletRequest; } private void pathFromRequest(HttpServletRequest request) { this.servletRequestURI = request.getRequestURI(); replacePath(request.getRequestURI()); } /** * Removes any path extension from the {@link HttpServletRequest#getRequestURI() * requestURI}. This method must be invoked before any calls to {@link #path(String)} * or {@link #pathSegment(String...)}. * <pre> * // GET http://foo.com/rest/books/6.json * * YourServletUriComponentsBuilder builder = YourServletUriComponentsBuilder.fromRequestUri(this.request); * String ext = builder.removePathExtension(); * String uri = builder.path("/pages/1.{ext}").buildAndExpand(ext).toUriString(); * * assertEquals("http://foo.com/rest/books/6/pages/1.json", result); * </pre> * @return the removed path extension for possible re-use, or {@code null} * @since 4.0 */ public String removePathExtension() { String extension = null; if (this.servletRequestURI != null) { String filename = WebUtils.extractFullFilenameFromUrlPath(this.servletRequestURI); extension = StringUtils.getFilenameExtension(filename); if (!StringUtils.isEmpty(extension)) { int end = this.servletRequestURI.length() - extension.length() + 1; replacePath(this.servletRequestURI.substring(0, end)); } this.servletRequestURI = null; } return extension; } }