/*
* 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.mvc;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.http.CacheControl;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.Assert;
import org.springframework.util.PathMatcher;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.support.WebContentGenerator;
import org.springframework.web.util.UrlPathHelper;
/**
* Handler interceptor that checks the request and prepares the response.
* Checks for supported methods and a required session, and applies the
* specified {@link org.springframework.http.CacheControl} builder.
* See superclass bean properties for configuration options.
*
* <p>All the settings supported by this interceptor can also be set on
* {@link AbstractController}. This interceptor is mainly intended for applying
* checks and preparations to a set of controllers mapped by a HandlerMapping.
*
* @author Juergen Hoeller
* @author Brian Clozel
* @since 27.11.2003
* @see AbstractController
*/
public class WebContentInterceptor extends WebContentGenerator implements HandlerInterceptor {
private UrlPathHelper urlPathHelper = new UrlPathHelper();
private PathMatcher pathMatcher = new AntPathMatcher();
private Map<String, Integer> cacheMappings = new HashMap<>();
private Map<String, CacheControl> cacheControlMappings = new HashMap<>();
public WebContentInterceptor() {
// No restriction of HTTP methods by default,
// in particular for use with annotated controllers...
super(false);
}
/**
* Set if URL lookup should always use full path within current servlet
* context. Else, the path within the current servlet mapping is used
* if applicable (i.e. in the case of a ".../*" servlet mapping in web.xml).
* Default is "false".
* <p>Only relevant for the "cacheMappings" setting.
* @see #setCacheMappings
* @see org.springframework.web.util.UrlPathHelper#setAlwaysUseFullPath
*/
public void setAlwaysUseFullPath(boolean alwaysUseFullPath) {
this.urlPathHelper.setAlwaysUseFullPath(alwaysUseFullPath);
}
/**
* Set if context path and request URI should be URL-decoded.
* Both are returned <i>undecoded</i> by the Servlet API,
* in contrast to the servlet path.
* <p>Uses either the request encoding or the default encoding according
* to the Servlet spec (ISO-8859-1).
* <p>Only relevant for the "cacheMappings" setting.
* @see #setCacheMappings
* @see org.springframework.web.util.UrlPathHelper#setUrlDecode
*/
public void setUrlDecode(boolean urlDecode) {
this.urlPathHelper.setUrlDecode(urlDecode);
}
/**
* Set the UrlPathHelper to use for resolution of lookup paths.
* <p>Use this to override the default UrlPathHelper with a custom subclass,
* or to share common UrlPathHelper settings across multiple HandlerMappings
* and MethodNameResolvers.
* <p>Only relevant for the "cacheMappings" setting.
* @see #setCacheMappings
* @see org.springframework.web.servlet.handler.AbstractUrlHandlerMapping#setUrlPathHelper
*/
public void setUrlPathHelper(UrlPathHelper urlPathHelper) {
Assert.notNull(urlPathHelper, "UrlPathHelper must not be null");
this.urlPathHelper = urlPathHelper;
}
/**
* Map specific URL paths to specific cache seconds.
* <p>Overrides the default cache seconds setting of this interceptor.
* Can specify "-1" to exclude a URL path from default caching.
* <p>Supports direct matches, e.g. a registered "/test" matches "/test",
* and a various Ant-style pattern matches, e.g. a registered "/t*" matches
* both "/test" and "/team". For details, see the AntPathMatcher javadoc.
* <p><b>NOTE:</b> Path patterns are not supposed to overlap. If a request
* matches several mappings, it is effectively undefined which one will apply
* (due to the lack of key ordering in {@code java.util.Properties}).
* @param cacheMappings a mapping between URL paths (as keys) and
* cache seconds (as values, need to be integer-parsable)
* @see #setCacheSeconds
* @see org.springframework.util.AntPathMatcher
*/
public void setCacheMappings(Properties cacheMappings) {
this.cacheMappings.clear();
Enumeration<?> propNames = cacheMappings.propertyNames();
while (propNames.hasMoreElements()) {
String path = (String) propNames.nextElement();
int cacheSeconds = Integer.valueOf(cacheMappings.getProperty(path));
this.cacheMappings.put(path, cacheSeconds);
}
}
/**
* Map specific URL paths to a specific {@link org.springframework.http.CacheControl}.
* <p>Overrides the default cache seconds setting of this interceptor.
* Can specify a empty {@link org.springframework.http.CacheControl} instance
* to exclude a URL path from default caching.
* <p>Supports direct matches, e.g. a registered "/test" matches "/test",
* and a various Ant-style pattern matches, e.g. a registered "/t*" matches
* both "/test" and "/team". For details, see the AntPathMatcher javadoc.
* <p><b>NOTE:</b> Path patterns are not supposed to overlap. If a request
* matches several mappings, it is effectively undefined which one will apply
* (due to the lack of key ordering in the underlying {@code java.util.HashMap}).
* @param cacheControl the {@code CacheControl} to use
* @param paths URL paths that will map to the given {@code CacheControl}
* @since 4.2
* @see #setCacheSeconds
* @see org.springframework.util.AntPathMatcher
*/
public void addCacheMapping(CacheControl cacheControl, String... paths) {
for (String path : paths) {
this.cacheControlMappings.put(path, cacheControl);
}
}
/**
* Set the PathMatcher implementation to use for matching URL paths
* against registered URL patterns, for determining cache mappings.
* Default is AntPathMatcher.
* @see #addCacheMapping
* @see #setCacheMappings
* @see org.springframework.util.AntPathMatcher
*/
public void setPathMatcher(PathMatcher pathMatcher) {
Assert.notNull(pathMatcher, "PathMatcher must not be null");
this.pathMatcher = pathMatcher;
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws ServletException {
checkRequest(request);
String lookupPath = this.urlPathHelper.getLookupPathForRequest(request);
if (logger.isDebugEnabled()) {
logger.debug("Looking up cache seconds for [" + lookupPath + "]");
}
CacheControl cacheControl = lookupCacheControl(lookupPath);
Integer cacheSeconds = lookupCacheSeconds(lookupPath);
if (cacheControl != null) {
if (logger.isDebugEnabled()) {
logger.debug("Applying CacheControl to [" + lookupPath + "]");
}
applyCacheControl(response, cacheControl);
}
else if (cacheSeconds != null) {
if (logger.isDebugEnabled()) {
logger.debug("Applying CacheControl to [" + lookupPath + "]");
}
applyCacheSeconds(response, cacheSeconds);
}
else {
if (logger.isDebugEnabled()) {
logger.debug("Applying default cache seconds to [" + lookupPath + "]");
}
prepareResponse(response);
}
return true;
}
/**
* Look up a {@link org.springframework.http.CacheControl} instance for the given URL path.
* <p>Supports direct matches, e.g. a registered "/test" matches "/test",
* and various Ant-style pattern matches, e.g. a registered "/t*" matches
* both "/test" and "/team". For details, see the AntPathMatcher class.
* @param urlPath URL the bean is mapped to
* @return the associated {@code CacheControl}, or {@code null} if not found
* @see org.springframework.util.AntPathMatcher
*/
protected CacheControl lookupCacheControl(String urlPath) {
// Direct match?
CacheControl cacheControl = this.cacheControlMappings.get(urlPath);
if (cacheControl != null) {
return cacheControl;
}
// Pattern match?
for (String registeredPath : this.cacheControlMappings.keySet()) {
if (this.pathMatcher.match(registeredPath, urlPath)) {
return this.cacheControlMappings.get(registeredPath);
}
}
return null;
}
/**
* Look up a cacheSeconds integer value for the given URL path.
* <p>Supports direct matches, e.g. a registered "/test" matches "/test",
* and various Ant-style pattern matches, e.g. a registered "/t*" matches
* both "/test" and "/team". For details, see the AntPathMatcher class.
* @param urlPath URL the bean is mapped to
* @return the cacheSeconds integer value, or {@code null} if not found
* @see org.springframework.util.AntPathMatcher
*/
protected Integer lookupCacheSeconds(String urlPath) {
// Direct match?
Integer cacheSeconds = this.cacheMappings.get(urlPath);
if (cacheSeconds != null) {
return cacheSeconds;
}
// Pattern match?
for (String registeredPath : this.cacheMappings.keySet()) {
if (this.pathMatcher.match(registeredPath, urlPath)) {
return this.cacheMappings.get(registeredPath);
}
}
return null;
}
/**
* This implementation is empty.
*/
@Override
public void postHandle(
HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
throws Exception {
}
/**
* This implementation is empty.
*/
@Override
public void afterCompletion(
HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
throws Exception {
}
}