001/*
002 * Copyright 2002-2020 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.util;
018
019import java.io.File;
020import java.io.FileNotFoundException;
021import java.util.Collection;
022import java.util.Enumeration;
023import java.util.Map;
024import java.util.StringTokenizer;
025import java.util.TreeMap;
026import javax.servlet.ServletContext;
027import javax.servlet.ServletRequest;
028import javax.servlet.ServletRequestWrapper;
029import javax.servlet.ServletResponse;
030import javax.servlet.ServletResponseWrapper;
031import javax.servlet.http.Cookie;
032import javax.servlet.http.HttpServletRequest;
033import javax.servlet.http.HttpServletResponse;
034import javax.servlet.http.HttpSession;
035
036import org.springframework.http.HttpRequest;
037import org.springframework.http.server.ServletServerHttpRequest;
038import org.springframework.util.Assert;
039import org.springframework.util.CollectionUtils;
040import org.springframework.util.LinkedMultiValueMap;
041import org.springframework.util.MultiValueMap;
042import org.springframework.util.ObjectUtils;
043import org.springframework.util.StringUtils;
044
045/**
046 * Miscellaneous utilities for web applications.
047 * Used by various framework classes.
048 *
049 * @author Rod Johnson
050 * @author Juergen Hoeller
051 * @author Sebastien Deleuze
052 */
053public abstract class WebUtils {
054
055        /**
056         * Standard Servlet 2.3+ spec request attributes for include URI and paths.
057         * <p>If included via a RequestDispatcher, the current resource will see the
058         * originating request. Its own URI and paths are exposed as request attributes.
059         */
060        public static final String INCLUDE_REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri";
061        public static final String INCLUDE_CONTEXT_PATH_ATTRIBUTE = "javax.servlet.include.context_path";
062        public static final String INCLUDE_SERVLET_PATH_ATTRIBUTE = "javax.servlet.include.servlet_path";
063        public static final String INCLUDE_PATH_INFO_ATTRIBUTE = "javax.servlet.include.path_info";
064        public static final String INCLUDE_QUERY_STRING_ATTRIBUTE = "javax.servlet.include.query_string";
065
066        /**
067         * Standard Servlet 2.4+ spec request attributes for forward URI and paths.
068         * <p>If forwarded to via a RequestDispatcher, the current resource will see its
069         * own URI and paths. The originating URI and paths are exposed as request attributes.
070         */
071        public static final String FORWARD_REQUEST_URI_ATTRIBUTE = "javax.servlet.forward.request_uri";
072        public static final String FORWARD_CONTEXT_PATH_ATTRIBUTE = "javax.servlet.forward.context_path";
073        public static final String FORWARD_SERVLET_PATH_ATTRIBUTE = "javax.servlet.forward.servlet_path";
074        public static final String FORWARD_PATH_INFO_ATTRIBUTE = "javax.servlet.forward.path_info";
075        public static final String FORWARD_QUERY_STRING_ATTRIBUTE = "javax.servlet.forward.query_string";
076
077        /**
078         * Standard Servlet 2.3+ spec request attributes for error pages.
079         * <p>To be exposed to JSPs that are marked as error pages, when forwarding
080         * to them directly rather than through the servlet container's error page
081         * resolution mechanism.
082         */
083        public static final String ERROR_STATUS_CODE_ATTRIBUTE = "javax.servlet.error.status_code";
084        public static final String ERROR_EXCEPTION_TYPE_ATTRIBUTE = "javax.servlet.error.exception_type";
085        public static final String ERROR_MESSAGE_ATTRIBUTE = "javax.servlet.error.message";
086        public static final String ERROR_EXCEPTION_ATTRIBUTE = "javax.servlet.error.exception";
087        public static final String ERROR_REQUEST_URI_ATTRIBUTE = "javax.servlet.error.request_uri";
088        public static final String ERROR_SERVLET_NAME_ATTRIBUTE = "javax.servlet.error.servlet_name";
089
090
091        /**
092         * Prefix of the charset clause in a content type String: ";charset="
093         */
094        public static final String CONTENT_TYPE_CHARSET_PREFIX = ";charset=";
095
096        /**
097         * Default character encoding to use when {@code request.getCharacterEncoding}
098         * returns {@code null}, according to the Servlet spec.
099         * @see ServletRequest#getCharacterEncoding
100         */
101        public static final String DEFAULT_CHARACTER_ENCODING = "ISO-8859-1";
102
103        /**
104         * Standard Servlet spec context attribute that specifies a temporary
105         * directory for the current web application, of type {@code java.io.File}.
106         */
107        public static final String TEMP_DIR_CONTEXT_ATTRIBUTE = "javax.servlet.context.tempdir";
108
109        /**
110         * HTML escape parameter at the servlet context level
111         * (i.e. a context-param in {@code web.xml}): "defaultHtmlEscape".
112         */
113        public static final String HTML_ESCAPE_CONTEXT_PARAM = "defaultHtmlEscape";
114
115        /**
116         * Use of response encoding for HTML escaping parameter at the servlet context level
117         * (i.e. a context-param in {@code web.xml}): "responseEncodedHtmlEscape".
118         * @since 4.1.2
119         */
120        public static final String RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM = "responseEncodedHtmlEscape";
121
122        /**
123         * Web app root key parameter at the servlet context level
124         * (i.e. a context-param in {@code web.xml}): "webAppRootKey".
125         */
126        public static final String WEB_APP_ROOT_KEY_PARAM = "webAppRootKey";
127
128        /** Default web app root key: "webapp.root" */
129        public static final String DEFAULT_WEB_APP_ROOT_KEY = "webapp.root";
130
131        /** Name suffixes in case of image buttons */
132        public static final String[] SUBMIT_IMAGE_SUFFIXES = {".x", ".y"};
133
134        /** Key for the mutex session attribute */
135        public static final String SESSION_MUTEX_ATTRIBUTE = WebUtils.class.getName() + ".MUTEX";
136
137
138        /**
139         * Set a system property to the web application root directory.
140         * The key of the system property can be defined with the "webAppRootKey"
141         * context-param in {@code web.xml}. Default is "webapp.root".
142         * <p>Can be used for tools that support substitution with {@code System.getProperty}
143         * values, like log4j's "${key}" syntax within log file locations.
144         * @param servletContext the servlet context of the web application
145         * @throws IllegalStateException if the system property is already set,
146         * or if the WAR file is not expanded
147         * @see #WEB_APP_ROOT_KEY_PARAM
148         * @see #DEFAULT_WEB_APP_ROOT_KEY
149         * @see WebAppRootListener
150         * @see Log4jWebConfigurer
151         */
152        public static void setWebAppRootSystemProperty(ServletContext servletContext) throws IllegalStateException {
153                Assert.notNull(servletContext, "ServletContext must not be null");
154                String root = servletContext.getRealPath("/");
155                if (root == null) {
156                        throw new IllegalStateException(
157                                        "Cannot set web app root system property when WAR file is not expanded");
158                }
159                String param = servletContext.getInitParameter(WEB_APP_ROOT_KEY_PARAM);
160                String key = (param != null ? param : DEFAULT_WEB_APP_ROOT_KEY);
161                String oldValue = System.getProperty(key);
162                if (oldValue != null && !StringUtils.pathEquals(oldValue, root)) {
163                        throw new IllegalStateException("Web app root system property already set to different value: '" +
164                                        key + "' = [" + oldValue + "] instead of [" + root + "] - " +
165                                        "Choose unique values for the 'webAppRootKey' context-param in your web.xml files!");
166                }
167                System.setProperty(key, root);
168                servletContext.log("Set web app root system property: '" + key + "' = [" + root + "]");
169        }
170
171        /**
172         * Remove the system property that points to the web app root directory.
173         * To be called on shutdown of the web application.
174         * @param servletContext the servlet context of the web application
175         * @see #setWebAppRootSystemProperty
176         */
177        public static void removeWebAppRootSystemProperty(ServletContext servletContext) {
178                Assert.notNull(servletContext, "ServletContext must not be null");
179                String param = servletContext.getInitParameter(WEB_APP_ROOT_KEY_PARAM);
180                String key = (param != null ? param : DEFAULT_WEB_APP_ROOT_KEY);
181                System.getProperties().remove(key);
182        }
183
184        /**
185         * Return whether default HTML escaping is enabled for the web application,
186         * i.e. the value of the "defaultHtmlEscape" context-param in {@code web.xml}
187         * (if any). Falls back to {@code false} in case of no explicit default given.
188         * @param servletContext the servlet context of the web application
189         * @return whether default HTML escaping is enabled (default is {@code false})
190         * @deprecated as of Spring 4.1, in favor of {@link #getDefaultHtmlEscape}
191         */
192        @Deprecated
193        public static boolean isDefaultHtmlEscape(ServletContext servletContext) {
194                if (servletContext == null) {
195                        return false;
196                }
197                String param = servletContext.getInitParameter(HTML_ESCAPE_CONTEXT_PARAM);
198                return Boolean.valueOf(param);
199        }
200
201        /**
202         * Return whether default HTML escaping is enabled for the web application,
203         * i.e. the value of the "defaultHtmlEscape" context-param in {@code web.xml}
204         * (if any).
205         * <p>This method differentiates between no param specified at all and
206         * an actual boolean value specified, allowing to have a context-specific
207         * default in case of no setting at the global level.
208         * @param servletContext the servlet context of the web application
209         * @return whether default HTML escaping is enabled for the given application
210         * ({@code null} = no explicit default)
211         */
212        public static Boolean getDefaultHtmlEscape(ServletContext servletContext) {
213                if (servletContext == null) {
214                        return null;
215                }
216                String param = servletContext.getInitParameter(HTML_ESCAPE_CONTEXT_PARAM);
217                return (StringUtils.hasText(param) ? Boolean.valueOf(param) : null);
218        }
219
220        /**
221         * Return whether response encoding should be used when HTML escaping characters,
222         * thus only escaping XML markup significant characters with UTF-* encodings.
223         * This option is enabled for the web application with a ServletContext param,
224         * i.e. the value of the "responseEncodedHtmlEscape" context-param in {@code web.xml}
225         * (if any).
226         * <p>This method differentiates between no param specified at all and
227         * an actual boolean value specified, allowing to have a context-specific
228         * default in case of no setting at the global level.
229         * @param servletContext the servlet context of the web application
230         * @return whether response encoding is to be used for HTML escaping
231         * ({@code null} = no explicit default)
232         * @since 4.1.2
233         */
234        public static Boolean getResponseEncodedHtmlEscape(ServletContext servletContext) {
235                if (servletContext == null) {
236                        return null;
237                }
238                String param = servletContext.getInitParameter(RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM);
239                return (StringUtils.hasText(param) ? Boolean.valueOf(param) : null);
240        }
241
242        /**
243         * Return the temporary directory for the current web application,
244         * as provided by the servlet container.
245         * @param servletContext the servlet context of the web application
246         * @return the File representing the temporary directory
247         */
248        public static File getTempDir(ServletContext servletContext) {
249                Assert.notNull(servletContext, "ServletContext must not be null");
250                return (File) servletContext.getAttribute(TEMP_DIR_CONTEXT_ATTRIBUTE);
251        }
252
253        /**
254         * Return the real path of the given path within the web application,
255         * as provided by the servlet container.
256         * <p>Prepends a slash if the path does not already start with a slash,
257         * and throws a FileNotFoundException if the path cannot be resolved to
258         * a resource (in contrast to ServletContext's {@code getRealPath},
259         * which returns null).
260         * @param servletContext the servlet context of the web application
261         * @param path the path within the web application
262         * @return the corresponding real path
263         * @throws FileNotFoundException if the path cannot be resolved to a resource
264         * @see javax.servlet.ServletContext#getRealPath
265         */
266        public static String getRealPath(ServletContext servletContext, String path) throws FileNotFoundException {
267                Assert.notNull(servletContext, "ServletContext must not be null");
268                // Interpret location as relative to the web application root directory.
269                if (!path.startsWith("/")) {
270                        path = "/" + path;
271                }
272                String realPath = servletContext.getRealPath(path);
273                if (realPath == null) {
274                        throw new FileNotFoundException(
275                                        "ServletContext resource [" + path + "] cannot be resolved to absolute file path - " +
276                                        "web application archive not expanded?");
277                }
278                return realPath;
279        }
280
281        /**
282         * Determine the session id of the given request, if any.
283         * @param request current HTTP request
284         * @return the session id, or {@code null} if none
285         */
286        public static String getSessionId(HttpServletRequest request) {
287                Assert.notNull(request, "Request must not be null");
288                HttpSession session = request.getSession(false);
289                return (session != null ? session.getId() : null);
290        }
291
292        /**
293         * Check the given request for a session attribute of the given name.
294         * Returns null if there is no session or if the session has no such attribute.
295         * Does not create a new session if none has existed before!
296         * @param request current HTTP request
297         * @param name the name of the session attribute
298         * @return the value of the session attribute, or {@code null} if not found
299         */
300        public static Object getSessionAttribute(HttpServletRequest request, String name) {
301                Assert.notNull(request, "Request must not be null");
302                HttpSession session = request.getSession(false);
303                return (session != null ? session.getAttribute(name) : null);
304        }
305
306        /**
307         * Check the given request for a session attribute of the given name.
308         * Throws an exception if there is no session or if the session has no such
309         * attribute. Does not create a new session if none has existed before!
310         * @param request current HTTP request
311         * @param name the name of the session attribute
312         * @return the value of the session attribute, or {@code null} if not found
313         * @throws IllegalStateException if the session attribute could not be found
314         */
315        public static Object getRequiredSessionAttribute(HttpServletRequest request, String name)
316                        throws IllegalStateException {
317
318                Object attr = getSessionAttribute(request, name);
319                if (attr == null) {
320                        throw new IllegalStateException("No session attribute '" + name + "' found");
321                }
322                return attr;
323        }
324
325        /**
326         * Set the session attribute with the given name to the given value.
327         * Removes the session attribute if value is null, if a session existed at all.
328         * Does not create a new session if not necessary!
329         * @param request current HTTP request
330         * @param name the name of the session attribute
331         * @param value the value of the session attribute
332         */
333        public static void setSessionAttribute(HttpServletRequest request, String name, Object value) {
334                Assert.notNull(request, "Request must not be null");
335                if (value != null) {
336                        request.getSession().setAttribute(name, value);
337                }
338                else {
339                        HttpSession session = request.getSession(false);
340                        if (session != null) {
341                                session.removeAttribute(name);
342                        }
343                }
344        }
345
346        /**
347         * Get the specified session attribute, creating and setting a new attribute if
348         * no existing found. The given class needs to have a public no-arg constructor.
349         * Useful for on-demand state objects in a web tier, like shopping carts.
350         * @param session current HTTP session
351         * @param name the name of the session attribute
352         * @param clazz the class to instantiate for a new attribute
353         * @return the value of the session attribute, newly created if not found
354         * @throws IllegalArgumentException if the session attribute could not be instantiated
355         * @deprecated as of Spring 4.3.2, in favor of custom code for such purposes
356         */
357        @Deprecated
358        public static Object getOrCreateSessionAttribute(HttpSession session, String name, Class<?> clazz)
359                        throws IllegalArgumentException {
360
361                Assert.notNull(session, "Session must not be null");
362                Object sessionObject = session.getAttribute(name);
363                if (sessionObject == null) {
364                        try {
365                                sessionObject = clazz.newInstance();
366                        }
367                        catch (InstantiationException ex) {
368                                throw new IllegalArgumentException(
369                                        "Could not instantiate class [" + clazz.getName() +
370                                        "] for session attribute '" + name + "': " + ex.getMessage());
371                        }
372                        catch (IllegalAccessException ex) {
373                                throw new IllegalArgumentException(
374                                        "Could not access default constructor of class [" + clazz.getName() +
375                                        "] for session attribute '" + name + "': " + ex.getMessage());
376                        }
377                        session.setAttribute(name, sessionObject);
378                }
379                return sessionObject;
380        }
381
382        /**
383         * Return the best available mutex for the given session:
384         * that is, an object to synchronize on for the given session.
385         * <p>Returns the session mutex attribute if available; usually,
386         * this means that the HttpSessionMutexListener needs to be defined
387         * in {@code web.xml}. Falls back to the HttpSession itself
388         * if no mutex attribute found.
389         * <p>The session mutex is guaranteed to be the same object during
390         * the entire lifetime of the session, available under the key defined
391         * by the {@code SESSION_MUTEX_ATTRIBUTE} constant. It serves as a
392         * safe reference to synchronize on for locking on the current session.
393         * <p>In many cases, the HttpSession reference itself is a safe mutex
394         * as well, since it will always be the same object reference for the
395         * same active logical session. However, this is not guaranteed across
396         * different servlet containers; the only 100% safe way is a session mutex.
397         * @param session the HttpSession to find a mutex for
398         * @return the mutex object (never {@code null})
399         * @see #SESSION_MUTEX_ATTRIBUTE
400         * @see HttpSessionMutexListener
401         */
402        public static Object getSessionMutex(HttpSession session) {
403                Assert.notNull(session, "Session must not be null");
404                Object mutex = session.getAttribute(SESSION_MUTEX_ATTRIBUTE);
405                if (mutex == null) {
406                        mutex = session;
407                }
408                return mutex;
409        }
410
411
412        /**
413         * Return an appropriate request object of the specified type, if available,
414         * unwrapping the given request as far as necessary.
415         * @param request the servlet request to introspect
416         * @param requiredType the desired type of request object
417         * @return the matching request object, or {@code null} if none
418         * of that type is available
419         */
420        @SuppressWarnings("unchecked")
421        public static <T> T getNativeRequest(ServletRequest request, Class<T> requiredType) {
422                if (requiredType != null) {
423                        if (requiredType.isInstance(request)) {
424                                return (T) request;
425                        }
426                        else if (request instanceof ServletRequestWrapper) {
427                                return getNativeRequest(((ServletRequestWrapper) request).getRequest(), requiredType);
428                        }
429                }
430                return null;
431        }
432
433        /**
434         * Return an appropriate response object of the specified type, if available,
435         * unwrapping the given response as far as necessary.
436         * @param response the servlet response to introspect
437         * @param requiredType the desired type of response object
438         * @return the matching response object, or {@code null} if none
439         * of that type is available
440         */
441        @SuppressWarnings("unchecked")
442        public static <T> T getNativeResponse(ServletResponse response, Class<T> requiredType) {
443                if (requiredType != null) {
444                        if (requiredType.isInstance(response)) {
445                                return (T) response;
446                        }
447                        else if (response instanceof ServletResponseWrapper) {
448                                return getNativeResponse(((ServletResponseWrapper) response).getResponse(), requiredType);
449                        }
450                }
451                return null;
452        }
453
454        /**
455         * Determine whether the given request is an include request,
456         * that is, not a top-level HTTP request coming in from the outside.
457         * <p>Checks the presence of the "javax.servlet.include.request_uri"
458         * request attribute. Could check any request attribute that is only
459         * present in an include request.
460         * @param request current servlet request
461         * @return whether the given request is an include request
462         */
463        public static boolean isIncludeRequest(ServletRequest request) {
464                return (request.getAttribute(INCLUDE_REQUEST_URI_ATTRIBUTE) != null);
465        }
466
467        /**
468         * Expose the Servlet spec's error attributes as {@link javax.servlet.http.HttpServletRequest}
469         * attributes under the keys defined in the Servlet 2.3 specification, for error pages that
470         * are rendered directly rather than through the Servlet container's error page resolution:
471         * {@code javax.servlet.error.status_code},
472         * {@code javax.servlet.error.exception_type},
473         * {@code javax.servlet.error.message},
474         * {@code javax.servlet.error.exception},
475         * {@code javax.servlet.error.request_uri},
476         * {@code javax.servlet.error.servlet_name}.
477         * <p>Does not override values if already present, to respect attribute values
478         * that have been exposed explicitly before.
479         * <p>Exposes status code 200 by default. Set the "javax.servlet.error.status_code"
480         * attribute explicitly (before or after) in order to expose a different status code.
481         * @param request current servlet request
482         * @param ex the exception encountered
483         * @param servletName the name of the offending servlet
484         */
485        public static void exposeErrorRequestAttributes(HttpServletRequest request, Throwable ex, String servletName) {
486                exposeRequestAttributeIfNotPresent(request, ERROR_STATUS_CODE_ATTRIBUTE, HttpServletResponse.SC_OK);
487                exposeRequestAttributeIfNotPresent(request, ERROR_EXCEPTION_TYPE_ATTRIBUTE, ex.getClass());
488                exposeRequestAttributeIfNotPresent(request, ERROR_MESSAGE_ATTRIBUTE, ex.getMessage());
489                exposeRequestAttributeIfNotPresent(request, ERROR_EXCEPTION_ATTRIBUTE, ex);
490                exposeRequestAttributeIfNotPresent(request, ERROR_REQUEST_URI_ATTRIBUTE, request.getRequestURI());
491                exposeRequestAttributeIfNotPresent(request, ERROR_SERVLET_NAME_ATTRIBUTE, servletName);
492        }
493
494        /**
495         * Expose the specified request attribute if not already present.
496         * @param request current servlet request
497         * @param name the name of the attribute
498         * @param value the suggested value of the attribute
499         */
500        private static void exposeRequestAttributeIfNotPresent(ServletRequest request, String name, Object value) {
501                if (request.getAttribute(name) == null) {
502                        request.setAttribute(name, value);
503                }
504        }
505
506        /**
507         * Clear the Servlet spec's error attributes as {@link javax.servlet.http.HttpServletRequest}
508         * attributes under the keys defined in the Servlet 2.3 specification:
509         * {@code javax.servlet.error.status_code},
510         * {@code javax.servlet.error.exception_type},
511         * {@code javax.servlet.error.message},
512         * {@code javax.servlet.error.exception},
513         * {@code javax.servlet.error.request_uri},
514         * {@code javax.servlet.error.servlet_name}.
515         * @param request current servlet request
516         */
517        public static void clearErrorRequestAttributes(HttpServletRequest request) {
518                request.removeAttribute(ERROR_STATUS_CODE_ATTRIBUTE);
519                request.removeAttribute(ERROR_EXCEPTION_TYPE_ATTRIBUTE);
520                request.removeAttribute(ERROR_MESSAGE_ATTRIBUTE);
521                request.removeAttribute(ERROR_EXCEPTION_ATTRIBUTE);
522                request.removeAttribute(ERROR_REQUEST_URI_ATTRIBUTE);
523                request.removeAttribute(ERROR_SERVLET_NAME_ATTRIBUTE);
524        }
525
526        /**
527         * Expose the given Map as request attributes, using the keys as attribute names
528         * and the values as corresponding attribute values. Keys need to be Strings.
529         * @param request current HTTP request
530         * @param attributes the attributes Map
531         * @deprecated as of Spring 4.3.2, in favor of custom code for such purposes
532         */
533        @Deprecated
534        public static void exposeRequestAttributes(ServletRequest request, Map<String, ?> attributes) {
535                Assert.notNull(request, "Request must not be null");
536                Assert.notNull(attributes, "Attributes Map must not be null");
537                for (Map.Entry<String, ?> entry : attributes.entrySet()) {
538                        request.setAttribute(entry.getKey(), entry.getValue());
539                }
540        }
541
542        /**
543         * Retrieve the first cookie with the given name. Note that multiple
544         * cookies can have the same name but different paths or domains.
545         * @param request current servlet request
546         * @param name cookie name
547         * @return the first cookie with the given name, or {@code null} if none is found
548         */
549        public static Cookie getCookie(HttpServletRequest request, String name) {
550                Assert.notNull(request, "Request must not be null");
551                Cookie[] cookies = request.getCookies();
552                if (cookies != null) {
553                        for (Cookie cookie : cookies) {
554                                if (name.equals(cookie.getName())) {
555                                        return cookie;
556                                }
557                        }
558                }
559                return null;
560        }
561
562        /**
563         * Check if a specific input type="submit" parameter was sent in the request,
564         * either via a button (directly with name) or via an image (name + ".x" or
565         * name + ".y").
566         * @param request current HTTP request
567         * @param name name of the parameter
568         * @return if the parameter was sent
569         * @see #SUBMIT_IMAGE_SUFFIXES
570         */
571        public static boolean hasSubmitParameter(ServletRequest request, String name) {
572                Assert.notNull(request, "Request must not be null");
573                if (request.getParameter(name) != null) {
574                        return true;
575                }
576                for (String suffix : SUBMIT_IMAGE_SUFFIXES) {
577                        if (request.getParameter(name + suffix) != null) {
578                                return true;
579                        }
580                }
581                return false;
582        }
583
584        /**
585         * Obtain a named parameter from the given request parameters.
586         * <p>See {@link #findParameterValue(java.util.Map, String)}
587         * for a description of the lookup algorithm.
588         * @param request current HTTP request
589         * @param name the <i>logical</i> name of the request parameter
590         * @return the value of the parameter, or {@code null}
591         * if the parameter does not exist in given request
592         */
593        public static String findParameterValue(ServletRequest request, String name) {
594                return findParameterValue(request.getParameterMap(), name);
595        }
596
597        /**
598         * Obtain a named parameter from the given request parameters.
599         * <p>This method will try to obtain a parameter value using the
600         * following algorithm:
601         * <ol>
602         * <li>Try to get the parameter value using just the given <i>logical</i> name.
603         * This handles parameters of the form <tt>logicalName = value</tt>. For normal
604         * parameters, e.g. submitted using a hidden HTML form field, this will return
605         * the requested value.</li>
606         * <li>Try to obtain the parameter value from the parameter name, where the
607         * parameter name in the request is of the form <tt>logicalName_value = xyz</tt>
608         * with "_" being the configured delimiter. This deals with parameter values
609         * submitted using an HTML form submit button.</li>
610         * <li>If the value obtained in the previous step has a ".x" or ".y" suffix,
611         * remove that. This handles cases where the value was submitted using an
612         * HTML form image button. In this case the parameter in the request would
613         * actually be of the form <tt>logicalName_value.x = 123</tt>. </li>
614         * </ol>
615         * @param parameters the available parameter map
616         * @param name the <i>logical</i> name of the request parameter
617         * @return the value of the parameter, or {@code null}
618         * if the parameter does not exist in given request
619         */
620        public static String findParameterValue(Map<String, ?> parameters, String name) {
621                // First try to get it as a normal name=value parameter
622                Object value = parameters.get(name);
623                if (value instanceof String[]) {
624                        String[] values = (String[]) value;
625                        return (values.length > 0 ? values[0] : null);
626                }
627                else if (value != null) {
628                        return value.toString();
629                }
630                // If no value yet, try to get it as a name_value=xyz parameter
631                String prefix = name + "_";
632                for (String paramName : parameters.keySet()) {
633                        if (paramName.startsWith(prefix)) {
634                                // Support images buttons, which would submit parameters as name_value.x=123
635                                for (String suffix : SUBMIT_IMAGE_SUFFIXES) {
636                                        if (paramName.endsWith(suffix)) {
637                                                return paramName.substring(prefix.length(), paramName.length() - suffix.length());
638                                        }
639                                }
640                                return paramName.substring(prefix.length());
641                        }
642                }
643                // We couldn't find the parameter value...
644                return null;
645        }
646
647        /**
648         * Return a map containing all parameters with the given prefix.
649         * Maps single values to String and multiple values to String array.
650         * <p>For example, with a prefix of "spring_", "spring_param1" and
651         * "spring_param2" result in a Map with "param1" and "param2" as keys.
652         * @param request HTTP request in which to look for parameters
653         * @param prefix the beginning of parameter names
654         * (if this is null or the empty string, all parameters will match)
655         * @return map containing request parameters <b>without the prefix</b>,
656         * containing either a String or a String array as values
657         * @see javax.servlet.ServletRequest#getParameterNames
658         * @see javax.servlet.ServletRequest#getParameterValues
659         * @see javax.servlet.ServletRequest#getParameterMap
660         */
661        public static Map<String, Object> getParametersStartingWith(ServletRequest request, String prefix) {
662                Assert.notNull(request, "Request must not be null");
663                Enumeration<String> paramNames = request.getParameterNames();
664                Map<String, Object> params = new TreeMap<String, Object>();
665                if (prefix == null) {
666                        prefix = "";
667                }
668                while (paramNames != null && paramNames.hasMoreElements()) {
669                        String paramName = paramNames.nextElement();
670                        if ("".equals(prefix) || paramName.startsWith(prefix)) {
671                                String unprefixed = paramName.substring(prefix.length());
672                                String[] values = request.getParameterValues(paramName);
673                                if (values == null || values.length == 0) {
674                                        // Do nothing, no values found at all.
675                                }
676                                else if (values.length > 1) {
677                                        params.put(unprefixed, values);
678                                }
679                                else {
680                                        params.put(unprefixed, values[0]);
681                                }
682                        }
683                }
684                return params;
685        }
686
687        /**
688         * Return the target page specified in the request.
689         * @param request current servlet request
690         * @param paramPrefix the parameter prefix to check for
691         * (e.g. "_target" for parameters like "_target1" or "_target2")
692         * @param currentPage the current page, to be returned as fallback
693         * if no target page specified
694         * @return the page specified in the request, or current page if not found
695         * @deprecated as of Spring 4.3.2, in favor of custom code for such purposes
696         */
697        @Deprecated
698        public static int getTargetPage(ServletRequest request, String paramPrefix, int currentPage) {
699                Enumeration<String> paramNames = request.getParameterNames();
700                while (paramNames.hasMoreElements()) {
701                        String paramName = paramNames.nextElement();
702                        if (paramName.startsWith(paramPrefix)) {
703                                for (int i = 0; i < WebUtils.SUBMIT_IMAGE_SUFFIXES.length; i++) {
704                                        String suffix = WebUtils.SUBMIT_IMAGE_SUFFIXES[i];
705                                        if (paramName.endsWith(suffix)) {
706                                                paramName = paramName.substring(0, paramName.length() - suffix.length());
707                                        }
708                                }
709                                return Integer.parseInt(paramName.substring(paramPrefix.length()));
710                        }
711                }
712                return currentPage;
713        }
714
715
716        /**
717         * Extract the URL filename from the given request URL path.
718         * Correctly resolves nested paths such as "/products/view.html" as well.
719         * @param urlPath the request URL path (e.g. "/index.html")
720         * @return the extracted URI filename (e.g. "index")
721         * @deprecated as of Spring 4.3.2, in favor of custom code for such purposes
722         */
723        @Deprecated
724        public static String extractFilenameFromUrlPath(String urlPath) {
725                String filename = extractFullFilenameFromUrlPath(urlPath);
726                int dotIndex = filename.lastIndexOf('.');
727                if (dotIndex != -1) {
728                        filename = filename.substring(0, dotIndex);
729                }
730                return filename;
731        }
732
733        /**
734         * Extract the full URL filename (including file extension) from the given
735         * request URL path. Correctly resolve nested paths such as
736         * "/products/view.html" and remove any path and or query parameters.
737         * @param urlPath the request URL path (e.g. "/products/index.html")
738         * @return the extracted URI filename (e.g. "index.html")
739         * @deprecated as of Spring 4.3.2, in favor of custom code for such purposes
740         * (or {@link UriUtils#extractFileExtension} for the file extension use case)
741         */
742        @Deprecated
743        public static String extractFullFilenameFromUrlPath(String urlPath) {
744                int end = urlPath.indexOf('?');
745                if (end == -1) {
746                        end = urlPath.indexOf('#');
747                        if (end == -1) {
748                                end = urlPath.length();
749                        }
750                }
751                int begin = urlPath.lastIndexOf('/', end) + 1;
752                int paramIndex = urlPath.indexOf(';', begin);
753                end = (paramIndex != -1 && paramIndex < end ? paramIndex : end);
754                return urlPath.substring(begin, end);
755        }
756
757        /**
758         * Parse the given string with matrix variables. An example string would look
759         * like this {@code "q1=a;q1=b;q2=a,b,c"}. The resulting map would contain
760         * keys {@code "q1"} and {@code "q2"} with values {@code ["a","b"]} and
761         * {@code ["a","b","c"]} respectively.
762         * @param matrixVariables the unparsed matrix variables string
763         * @return a map with matrix variable names and values (never {@code null})
764         * @since 3.2
765         */
766        public static MultiValueMap<String, String> parseMatrixVariables(String matrixVariables) {
767                MultiValueMap<String, String> result = new LinkedMultiValueMap<String, String>();
768                if (!StringUtils.hasText(matrixVariables)) {
769                        return result;
770                }
771                StringTokenizer pairs = new StringTokenizer(matrixVariables, ";");
772                while (pairs.hasMoreTokens()) {
773                        String pair = pairs.nextToken();
774                        int index = pair.indexOf('=');
775                        if (index != -1) {
776                                String name = pair.substring(0, index);
777                                if (name.equalsIgnoreCase("jsessionid")) {
778                                        continue;
779                                }
780                                String rawValue = pair.substring(index + 1);
781                                for (String value : StringUtils.commaDelimitedListToStringArray(rawValue)) {
782                                        result.add(name, value);
783                                }
784                        }
785                        else {
786                                result.add(pair, "");
787                        }
788                }
789                return result;
790        }
791
792        /**
793         * Check the given request origin against a list of allowed origins.
794         * A list containing "*" means that all origins are allowed.
795         * An empty list means only same origin is allowed.
796         * <p><strong>Note:</strong> this method may use values from "Forwarded"
797         * (<a href="https://tools.ietf.org/html/rfc7239">RFC 7239</a>),
798         * "X-Forwarded-Host", "X-Forwarded-Port", and "X-Forwarded-Proto" headers,
799         * if present, in order to reflect the client-originated address.
800         * Consider using the {@code ForwardedHeaderFilter} in order to choose from a
801         * central place whether to extract and use, or to discard such headers.
802         * See the Spring Framework reference for more on this filter.
803         * @return {@code true} if the request origin is valid, {@code false} otherwise
804         * @since 4.1.5
805         * @see <a href="https://tools.ietf.org/html/rfc6454">RFC 6454: The Web Origin Concept</a>
806         */
807        public static boolean isValidOrigin(HttpRequest request, Collection<String> allowedOrigins) {
808                Assert.notNull(request, "Request must not be null");
809                Assert.notNull(allowedOrigins, "Allowed origins must not be null");
810
811                String origin = request.getHeaders().getOrigin();
812                if (origin == null || allowedOrigins.contains("*")) {
813                        return true;
814                }
815                else if (CollectionUtils.isEmpty(allowedOrigins)) {
816                        return isSameOrigin(request);
817                }
818                else {
819                        return allowedOrigins.contains(origin);
820                }
821        }
822
823        /**
824         * Check if the request is a same-origin one, based on {@code Origin}, {@code Host},
825         * {@code Forwarded}, {@code X-Forwarded-Proto}, {@code X-Forwarded-Host} and
826         * @code X-Forwarded-Port} headers.
827         * <p><strong>Note:</strong> this method uses values from "Forwarded"
828         * (<a href="https://tools.ietf.org/html/rfc7239">RFC 7239</a>),
829         * "X-Forwarded-Host", "X-Forwarded-Port", and "X-Forwarded-Proto" headers,
830         * if present, in order to reflect the client-originated address.
831         * Consider using the {@code ForwardedHeaderFilter} in order to choose from a
832         * central place whether to extract and use, or to discard such headers.
833         * See the Spring Framework reference for more on this filter.
834         * @return {@code true} if the request is a same-origin one, {@code false} in case
835         * of cross-origin request
836         * @since 4.2
837         */
838        public static boolean isSameOrigin(HttpRequest request) {
839                String origin = request.getHeaders().getOrigin();
840                if (origin == null) {
841                        return true;
842                }
843                UriComponentsBuilder urlBuilder;
844                if (request instanceof ServletServerHttpRequest) {
845                        // Build more efficiently if we can: we only need scheme, host, port for origin comparison
846                        HttpServletRequest servletRequest = ((ServletServerHttpRequest) request).getServletRequest();
847                        urlBuilder = new UriComponentsBuilder().
848                                        scheme(servletRequest.getScheme()).
849                                        host(servletRequest.getServerName()).
850                                        port(servletRequest.getServerPort()).
851                                        adaptFromForwardedHeaders(request.getHeaders());
852                }
853                else {
854                        urlBuilder = UriComponentsBuilder.fromHttpRequest(request);
855                }
856                UriComponents actualUrl = urlBuilder.build();
857                UriComponents originUrl = UriComponentsBuilder.fromOriginHeader(origin).build();
858                return (ObjectUtils.nullSafeEquals(actualUrl.getHost(), originUrl.getHost()) &&
859                                getPort(actualUrl) == getPort(originUrl));
860        }
861
862        private static int getPort(UriComponents uri) {
863                int port = uri.getPort();
864                if (port == -1) {
865                        if ("http".equals(uri.getScheme()) || "ws".equals(uri.getScheme())) {
866                                port = 80;
867                        }
868                        else if ("https".equals(uri.getScheme()) || "wss".equals(uri.getScheme())) {
869                                port = 443;
870                        }
871                }
872                return port;
873        }
874
875}