1 /*
2 * Copyright 2002-2014 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.web.servlet.handler;
18
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.List;
22 import javax.servlet.http.HttpServletRequest;
23
24 import org.springframework.beans.BeansException;
25 import org.springframework.beans.factory.BeanFactoryUtils;
26 import org.springframework.core.Ordered;
27 import org.springframework.util.AntPathMatcher;
28 import org.springframework.util.Assert;
29 import org.springframework.util.PathMatcher;
30 import org.springframework.web.context.request.WebRequestInterceptor;
31 import org.springframework.web.context.support.WebApplicationObjectSupport;
32 import org.springframework.web.servlet.HandlerExecutionChain;
33 import org.springframework.web.servlet.HandlerInterceptor;
34 import org.springframework.web.servlet.HandlerMapping;
35 import org.springframework.web.util.UrlPathHelper;
36
37 /**
38 * Abstract base class for {@link org.springframework.web.servlet.HandlerMapping}
39 * implementations. Supports ordering, a default handler, handler interceptors,
40 * including handler interceptors mapped by path patterns.
41 *
42 * <p>Note: This base class does <i>not</i> support exposure of the
43 * {@link #PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE}. Support for this attribute
44 * is up to concrete subclasses, typically based on request URL mappings.
45 *
46 * @author Juergen Hoeller
47 * @author Rossen Stoyanchev
48 * @since 07.04.2003
49 * @see #getHandlerInternal
50 * @see #setDefaultHandler
51 * @see #setAlwaysUseFullPath
52 * @see #setUrlDecode
53 * @see org.springframework.util.AntPathMatcher
54 * @see #setInterceptors
55 * @see org.springframework.web.servlet.HandlerInterceptor
56 */
57 public abstract class AbstractHandlerMapping extends WebApplicationObjectSupport
58 implements HandlerMapping, Ordered {
59
60 private int order = Integer.MAX_VALUE; // default: same as non-Ordered
61
62 private Object defaultHandler;
63
64 private UrlPathHelper urlPathHelper = new UrlPathHelper();
65
66 private PathMatcher pathMatcher = new AntPathMatcher();
67
68 private final List<Object> interceptors = new ArrayList<Object>();
69
70 private final List<HandlerInterceptor> adaptedInterceptors = new ArrayList<HandlerInterceptor>();
71
72 private final List<MappedInterceptor> mappedInterceptors = new ArrayList<MappedInterceptor>();
73
74
75 /**
76 * Specify the order value for this HandlerMapping bean.
77 * <p>Default value is {@code Integer.MAX_VALUE}, meaning that it's non-ordered.
78 * @see org.springframework.core.Ordered#getOrder()
79 */
80 public final void setOrder(int order) {
81 this.order = order;
82 }
83
84 @Override
85 public final int getOrder() {
86 return this.order;
87 }
88
89 /**
90 * Set the default handler for this handler mapping.
91 * This handler will be returned if no specific mapping was found.
92 * <p>Default is {@code null}, indicating no default handler.
93 */
94 public void setDefaultHandler(Object defaultHandler) {
95 this.defaultHandler = defaultHandler;
96 }
97
98 /**
99 * Return the default handler for this handler mapping,
100 * or {@code null} if none.
101 */
102 public Object getDefaultHandler() {
103 return this.defaultHandler;
104 }
105
106 /**
107 * Set if URL lookup should always use the full path within the current servlet
108 * context. Else, the path within the current servlet mapping is used if applicable
109 * (that is, in the case of a ".../*" servlet mapping in web.xml).
110 * <p>Default is "false".
111 * @see org.springframework.web.util.UrlPathHelper#setAlwaysUseFullPath
112 */
113 public void setAlwaysUseFullPath(boolean alwaysUseFullPath) {
114 this.urlPathHelper.setAlwaysUseFullPath(alwaysUseFullPath);
115 }
116
117 /**
118 * Set if context path and request URI should be URL-decoded. Both are returned
119 * <i>undecoded</i> by the Servlet API, in contrast to the servlet path.
120 * <p>Uses either the request encoding or the default encoding according
121 * to the Servlet spec (ISO-8859-1).
122 * @see org.springframework.web.util.UrlPathHelper#setUrlDecode
123 */
124 public void setUrlDecode(boolean urlDecode) {
125 this.urlPathHelper.setUrlDecode(urlDecode);
126 }
127
128 /**
129 * Set if ";" (semicolon) content should be stripped from the request URI.
130 * <p>The default value is {@code true}.
131 * @see org.springframework.web.util.UrlPathHelper#setRemoveSemicolonContent(boolean)
132 */
133 public void setRemoveSemicolonContent(boolean removeSemicolonContent) {
134 this.urlPathHelper.setRemoveSemicolonContent(removeSemicolonContent);
135 }
136
137 /**
138 * Set the UrlPathHelper to use for resolution of lookup paths.
139 * <p>Use this to override the default UrlPathHelper with a custom subclass,
140 * or to share common UrlPathHelper settings across multiple HandlerMappings
141 * and MethodNameResolvers.
142 */
143 public void setUrlPathHelper(UrlPathHelper urlPathHelper) {
144 Assert.notNull(urlPathHelper, "UrlPathHelper must not be null");
145 this.urlPathHelper = urlPathHelper;
146 }
147
148 /**
149 * Return the UrlPathHelper implementation to use for resolution of lookup paths.
150 */
151 public UrlPathHelper getUrlPathHelper() {
152 return urlPathHelper;
153 }
154
155 /**
156 * Set the PathMatcher implementation to use for matching URL paths
157 * against registered URL patterns. Default is AntPathMatcher.
158 * @see org.springframework.util.AntPathMatcher
159 */
160 public void setPathMatcher(PathMatcher pathMatcher) {
161 Assert.notNull(pathMatcher, "PathMatcher must not be null");
162 this.pathMatcher = pathMatcher;
163 }
164
165 /**
166 * Return the PathMatcher implementation to use for matching URL paths
167 * against registered URL patterns.
168 */
169 public PathMatcher getPathMatcher() {
170 return this.pathMatcher;
171 }
172
173 /**
174 * Set the interceptors to apply for all handlers mapped by this handler mapping.
175 * <p>Supported interceptor types are HandlerInterceptor, WebRequestInterceptor, and MappedInterceptor.
176 * Mapped interceptors apply only to request URLs that match its path patterns.
177 * Mapped interceptor beans are also detected by type during initialization.
178 * @param interceptors array of handler interceptors, or {@code null} if none
179 * @see #adaptInterceptor
180 * @see org.springframework.web.servlet.HandlerInterceptor
181 * @see org.springframework.web.context.request.WebRequestInterceptor
182 */
183 public void setInterceptors(Object[] interceptors) {
184 this.interceptors.addAll(Arrays.asList(interceptors));
185 }
186
187
188 /**
189 * Initializes the interceptors.
190 * @see #extendInterceptors(java.util.List)
191 * @see #initInterceptors()
192 */
193 @Override
194 protected void initApplicationContext() throws BeansException {
195 extendInterceptors(this.interceptors);
196 detectMappedInterceptors(this.mappedInterceptors);
197 initInterceptors();
198 }
199
200 /**
201 * Extension hook that subclasses can override to register additional interceptors,
202 * given the configured interceptors (see {@link #setInterceptors}).
203 * <p>Will be invoked before {@link #initInterceptors()} adapts the specified
204 * interceptors into {@link HandlerInterceptor} instances.
205 * <p>The default implementation is empty.
206 * @param interceptors the configured interceptor List (never {@code null}), allowing
207 * to add further interceptors before as well as after the existing interceptors
208 */
209 protected void extendInterceptors(List<Object> interceptors) {
210 }
211
212 /**
213 * Detect beans of type {@link MappedInterceptor} and add them to the list of mapped interceptors.
214 * <p>This is called in addition to any {@link MappedInterceptor}s that may have been provided
215 * via {@link #setInterceptors}, by default adding all beans of type {@link MappedInterceptor}
216 * from the current context and its ancestors. Subclasses can override and refine this policy.
217 * @param mappedInterceptors an empty list to add {@link MappedInterceptor} instances to
218 */
219 protected void detectMappedInterceptors(List<MappedInterceptor> mappedInterceptors) {
220 mappedInterceptors.addAll(
221 BeanFactoryUtils.beansOfTypeIncludingAncestors(
222 getApplicationContext(), MappedInterceptor.class, true, false).values());
223 }
224
225 /**
226 * Initialize the specified interceptors, checking for {@link MappedInterceptor}s and
227 * adapting {@link HandlerInterceptor}s and {@link WebRequestInterceptor}s if necessary.
228 * @see #setInterceptors
229 * @see #adaptInterceptor
230 */
231 protected void initInterceptors() {
232 if (!this.interceptors.isEmpty()) {
233 for (int i = 0; i < this.interceptors.size(); i++) {
234 Object interceptor = this.interceptors.get(i);
235 if (interceptor == null) {
236 throw new IllegalArgumentException("Entry number " + i + " in interceptors array is null");
237 }
238 if (interceptor instanceof MappedInterceptor) {
239 this.mappedInterceptors.add((MappedInterceptor) interceptor);
240 }
241 else {
242 this.adaptedInterceptors.add(adaptInterceptor(interceptor));
243 }
244 }
245 }
246 }
247
248 /**
249 * Adapt the given interceptor object to the {@link HandlerInterceptor} interface.
250 * <p>By default, the supported interceptor types are {@link HandlerInterceptor}
251 * and {@link WebRequestInterceptor}. Each given {@link WebRequestInterceptor}
252 * will be wrapped in a {@link WebRequestHandlerInterceptorAdapter}.
253 * Can be overridden in subclasses.
254 * @param interceptor the specified interceptor object
255 * @return the interceptor wrapped as HandlerInterceptor
256 * @see org.springframework.web.servlet.HandlerInterceptor
257 * @see org.springframework.web.context.request.WebRequestInterceptor
258 * @see WebRequestHandlerInterceptorAdapter
259 */
260 protected HandlerInterceptor adaptInterceptor(Object interceptor) {
261 if (interceptor instanceof HandlerInterceptor) {
262 return (HandlerInterceptor) interceptor;
263 }
264 else if (interceptor instanceof WebRequestInterceptor) {
265 return new WebRequestHandlerInterceptorAdapter((WebRequestInterceptor) interceptor);
266 }
267 else {
268 throw new IllegalArgumentException("Interceptor type not supported: " + interceptor.getClass().getName());
269 }
270 }
271
272 /**
273 * Return the adapted interceptors as {@link HandlerInterceptor} array.
274 * @return the array of {@link HandlerInterceptor}s, or {@code null} if none
275 */
276 protected final HandlerInterceptor[] getAdaptedInterceptors() {
277 int count = this.adaptedInterceptors.size();
278 return (count > 0 ? this.adaptedInterceptors.toArray(new HandlerInterceptor[count]) : null);
279 }
280
281 /**
282 * Return all configured {@link MappedInterceptor}s as an array.
283 * @return the array of {@link MappedInterceptor}s, or {@code null} if none
284 */
285 protected final MappedInterceptor[] getMappedInterceptors() {
286 int count = this.mappedInterceptors.size();
287 return (count > 0 ? this.mappedInterceptors.toArray(new MappedInterceptor[count]) : null);
288 }
289
290 /**
291 * Look up a handler for the given request, falling back to the default
292 * handler if no specific one is found.
293 * @param request current HTTP request
294 * @return the corresponding handler instance, or the default handler
295 * @see #getHandlerInternal
296 */
297 @Override
298 public final HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
299 Object handler = getHandlerInternal(request);
300 if (handler == null) {
301 handler = getDefaultHandler();
302 }
303 if (handler == null) {
304 return null;
305 }
306 // Bean name or resolved handler?
307 if (handler instanceof String) {
308 String handlerName = (String) handler;
309 handler = getApplicationContext().getBean(handlerName);
310 }
311 return getHandlerExecutionChain(handler, request);
312 }
313
314 /**
315 * Look up a handler for the given request, returning {@code null} if no
316 * specific one is found. This method is called by {@link #getHandler};
317 * a {@code null} return value will lead to the default handler, if one is set.
318 * <p>Note: This method may also return a pre-built {@link HandlerExecutionChain},
319 * combining a handler object with dynamically determined interceptors.
320 * Statically specified interceptors will get merged into such an existing chain.
321 * @param request current HTTP request
322 * @return the corresponding handler instance, or {@code null} if none found
323 * @throws Exception if there is an internal error
324 */
325 protected abstract Object getHandlerInternal(HttpServletRequest request) throws Exception;
326
327 /**
328 * Build a {@link HandlerExecutionChain} for the given handler, including
329 * applicable interceptors.
330 * <p>The default implementation builds a standard {@link HandlerExecutionChain}
331 * with the given handler, the handler mapping's common interceptors, and any
332 * {@link MappedInterceptor}s matching to the current request URL. Subclasses
333 * may override this in order to extend/rearrange the list of interceptors.
334 * <p><b>NOTE:</b> The passed-in handler object may be a raw handler or a
335 * pre-built {@link HandlerExecutionChain}. This method should handle those
336 * two cases explicitly, either building a new {@link HandlerExecutionChain}
337 * or extending the existing chain.
338 * <p>For simply adding an interceptor in a custom subclass, consider calling
339 * {@code super.getHandlerExecutionChain(handler, request)} and invoking
340 * {@link HandlerExecutionChain#addInterceptor} on the returned chain object.
341 * @param handler the resolved handler instance (never {@code null})
342 * @param request current HTTP request
343 * @return the HandlerExecutionChain (never {@code null})
344 * @see #getAdaptedInterceptors()
345 */
346 protected HandlerExecutionChain getHandlerExecutionChain(Object handler, HttpServletRequest request) {
347 HandlerExecutionChain chain = (handler instanceof HandlerExecutionChain ?
348 (HandlerExecutionChain) handler : new HandlerExecutionChain(handler));
349 chain.addInterceptors(getAdaptedInterceptors());
350
351 String lookupPath = this.urlPathHelper.getLookupPathForRequest(request);
352 for (MappedInterceptor mappedInterceptor : this.mappedInterceptors) {
353 if (mappedInterceptor.matches(lookupPath, this.pathMatcher)) {
354 chain.addInterceptor(mappedInterceptor.getInterceptor());
355 }
356 }
357
358 return chain;
359 }
360
361 }