/*
* Copyright 2002-2017 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.
*/
package org.springframework.web.servlet.support;
import java.util.Enumeration;
import javax.servlet.http.HttpServletRequest;
import org.springframework.http.HttpRequest;
import org.springframework.http.server.ServletServerHttpRequest;
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.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;
import org.springframework.web.util.UriUtils;
import org.springframework.web.util.UrlPathHelper;
/**
* A UriComponentsBuilder that extracts information from the HttpServletRequest.
*
* @author Rossen Stoyanchev
* @since 3.1
*/
public class ServletUriComponentsBuilder extends UriComponentsBuilder {
private String originalPath;
/**
* Default constructor. Protected to prevent direct instantiation.
* @see #fromContextPath(HttpServletRequest)
* @see #fromServletMapping(HttpServletRequest)
* @see #fromRequest(HttpServletRequest)
* @see #fromCurrentContextPath()
* @see #fromCurrentServletMapping()
* @see #fromCurrentRequest()
*/
protected ServletUriComponentsBuilder() {
}
/**
* Create a deep copy of the given ServletUriComponentsBuilder.
* @param other the other builder to copy from
*/
protected ServletUriComponentsBuilder(ServletUriComponentsBuilder other) {
super(other);
this.originalPath = other.originalPath;
}
// Factory methods based on a HttpServletRequest
/**
* Prepare a builder from the host, port, scheme, and context path of the
* given HttpServletRequest.
*/
public static ServletUriComponentsBuilder fromContextPath(HttpServletRequest request) {
ServletUriComponentsBuilder builder = initFromRequest(request);
builder.replacePath(prependForwardedPrefix(request, request.getContextPath()));
return builder;
}
/**
* Prepare a builder from the host, port, scheme, context path, and
* servlet mapping of the given HttpServletRequest.
* <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)}.
*/
public static ServletUriComponentsBuilder fromServletMapping(HttpServletRequest request) {
ServletUriComponentsBuilder 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 (but not the query)
* of the HttpServletRequest.
*/
public static ServletUriComponentsBuilder fromRequestUri(HttpServletRequest request) {
ServletUriComponentsBuilder builder = initFromRequest(request);
builder.initPath(prependForwardedPrefix(request, request.getRequestURI()));
return builder;
}
/**
* Prepare a builder by copying the scheme, host, port, path, and
* query string of an HttpServletRequest.
*/
public static ServletUriComponentsBuilder fromRequest(HttpServletRequest request) {
ServletUriComponentsBuilder builder = initFromRequest(request);
builder.initPath(prependForwardedPrefix(request, request.getRequestURI()));
builder.query(request.getQueryString());
return builder;
}
/**
* Initialize a builder with a scheme, host,and port (but not path and query).
*/
private static ServletUriComponentsBuilder initFromRequest(HttpServletRequest request) {
HttpRequest httpRequest = new ServletServerHttpRequest(request);
UriComponents uriComponents = UriComponentsBuilder.fromHttpRequest(httpRequest).build();
String scheme = uriComponents.getScheme();
String host = uriComponents.getHost();
int port = uriComponents.getPort();
ServletUriComponentsBuilder builder = new ServletUriComponentsBuilder();
builder.scheme(scheme);
builder.host(host);
if (("http".equals(scheme) && port != 80) || ("https".equals(scheme) && port != 443)) {
builder.port(port);
}
return builder;
}
private static String prependForwardedPrefix(HttpServletRequest request, String path) {
String prefix = null;
Enumeration<String> names = request.getHeaderNames();
while (names.hasMoreElements()) {
String name = names.nextElement();
if ("X-Forwarded-Prefix".equalsIgnoreCase(name)) {
prefix = request.getHeader(name);
}
}
if (prefix != null) {
path = prefix + path;
}
return path;
}
// Alternative methods relying on RequestContextHolder to find the request
/**
* Same as {@link #fromContextPath(HttpServletRequest)} except the
* request is obtained through {@link RequestContextHolder}.
*/
public static ServletUriComponentsBuilder fromCurrentContextPath() {
return fromContextPath(getCurrentRequest());
}
/**
* Same as {@link #fromServletMapping(HttpServletRequest)} except the
* request is obtained through {@link RequestContextHolder}.
*/
public static ServletUriComponentsBuilder fromCurrentServletMapping() {
return fromServletMapping(getCurrentRequest());
}
/**
* Same as {@link #fromRequestUri(HttpServletRequest)} except the
* request is obtained through {@link RequestContextHolder}.
*/
public static ServletUriComponentsBuilder fromCurrentRequestUri() {
return fromRequestUri(getCurrentRequest());
}
/**
* Same as {@link #fromRequest(HttpServletRequest)} except the
* request is obtained through {@link RequestContextHolder}.
*/
public static ServletUriComponentsBuilder fromCurrentRequest() {
return fromRequest(getCurrentRequest());
}
/**
* Obtain current request through {@link RequestContextHolder}.
*/
protected static HttpServletRequest getCurrentRequest() {
RequestAttributes attrs = RequestContextHolder.getRequestAttributes();
Assert.state(attrs instanceof ServletRequestAttributes, "No current ServletRequestAttributes");
return ((ServletRequestAttributes) attrs).getRequest();
}
private void initPath(String path) {
this.originalPath = path;
replacePath(path);
}
/**
* Remove 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
*
* ServletUriComponentsBuilder builder = ServletUriComponentsBuilder.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.originalPath != null) {
extension = UriUtils.extractFileExtension(this.originalPath);
if (!StringUtils.isEmpty(extension)) {
int end = this.originalPath.length() - (extension.length() + 1);
replacePath(this.originalPath.substring(0, end));
}
this.originalPath = null;
}
return extension;
}
@Override
public ServletUriComponentsBuilder cloneBuilder() {
return new ServletUriComponentsBuilder(this);
}
}