/*
* Copyright 2002-2016 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.config.annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletContext;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.context.ApplicationContext;
import org.springframework.util.Assert;
import org.springframework.web.HttpRequestHandler;
import org.springframework.web.accept.ContentNegotiationManager;
import org.springframework.web.servlet.HandlerMapping;
import org.springframework.web.servlet.handler.AbstractHandlerMapping;
import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
/**
* Stores registrations of resource handlers for serving static resources such as images, css files and others
* through Spring MVC including setting cache headers optimized for efficient loading in a web browser.
* Resources can be served out of locations under web application root, from the classpath, and others.
*
* <p>To create a resource handler, use {@link #addResourceHandler(String...)} providing the URL path patterns
* for which the handler should be invoked to serve static resources (e.g. {@code "/resources/**"}).
*
* <p>Then use additional methods on the returned {@link ResourceHandlerRegistration} to add one or more
* locations from which to serve static content from (e.g. {{@code "/"},
* {@code "classpath:/META-INF/public-web-resources/"}}) or to specify a cache period for served resources.
*
* @author Rossen Stoyanchev
* @since 3.1
* @see DefaultServletHandlerConfigurer
*/
public class ResourceHandlerRegistry {
private final ServletContext servletContext;
private final ApplicationContext applicationContext;
private final ContentNegotiationManager contentNegotiationManager;
private final List<ResourceHandlerRegistration> registrations = new ArrayList<>();
private int order = Integer.MAX_VALUE -1;
/**
* Create a new resource handler registry for the given application context.
* @param applicationContext the Spring application context
* @param servletContext the corresponding Servlet context
*/
public ResourceHandlerRegistry(ApplicationContext applicationContext, ServletContext servletContext) {
this(applicationContext, servletContext, null);
}
/**
* Create a new resource handler registry for the given application context.
* @param applicationContext the Spring application context
* @param servletContext the corresponding Servlet context
* @param contentNegotiationManager the content negotiation manager to use
* @since 4.3
*/
public ResourceHandlerRegistry(ApplicationContext applicationContext, ServletContext servletContext,
ContentNegotiationManager contentNegotiationManager) {
Assert.notNull(applicationContext, "ApplicationContext is required");
this.applicationContext = applicationContext;
this.servletContext = servletContext;
this.contentNegotiationManager = contentNegotiationManager;
}
/**
* Add a resource handler for serving static resources based on the specified URL path
* patterns. The handler will be invoked for every incoming request that matches to
* one of the specified path patterns.
* <p>Patterns like {@code "/static/**"} or {@code "/css/{filename:\\w+\\.css}"}
* are allowed. See {@link org.springframework.util.AntPathMatcher} for more details on the
* syntax.
* @return A {@link ResourceHandlerRegistration} to use to further configure the
* registered resource handler
*/
public ResourceHandlerRegistration addResourceHandler(String... pathPatterns) {
ResourceHandlerRegistration registration =
new ResourceHandlerRegistration(this.applicationContext, pathPatterns);
this.registrations.add(registration);
return registration;
}
/**
* Whether a resource handler has already been registered for the given path pattern.
*/
public boolean hasMappingForPattern(String pathPattern) {
for (ResourceHandlerRegistration registration : this.registrations) {
if (Arrays.asList(registration.getPathPatterns()).contains(pathPattern)) {
return true;
}
}
return false;
}
/**
* Specify the order to use for resource handling relative to other {@link HandlerMapping}s
* configured in the Spring MVC application context.
* <p>The default value used is {@code Integer.MAX_VALUE-1}.
*/
public ResourceHandlerRegistry setOrder(int order) {
this.order = order;
return this;
}
/**
* Return a handler mapping with the mapped resource handlers; or {@code null} in case
* of no registrations.
*/
protected AbstractHandlerMapping getHandlerMapping() {
if (this.registrations.isEmpty()) {
return null;
}
Map<String, HttpRequestHandler> urlMap = new LinkedHashMap<>();
for (ResourceHandlerRegistration registration : this.registrations) {
for (String pathPattern : registration.getPathPatterns()) {
ResourceHttpRequestHandler handler = registration.getRequestHandler();
handler.setServletContext(this.servletContext);
handler.setApplicationContext(this.applicationContext);
handler.setContentNegotiationManager(this.contentNegotiationManager);
try {
handler.afterPropertiesSet();
}
catch (Throwable ex) {
throw new BeanInitializationException("Failed to init ResourceHttpRequestHandler", ex);
}
urlMap.put(pathPattern, handler);
}
}
SimpleUrlHandlerMapping handlerMapping = new SimpleUrlHandlerMapping();
handlerMapping.setOrder(order);
handlerMapping.setUrlMap(urlMap);
return handlerMapping;
}
}