org.springframework.web.servlet.config.annotation.ResourceHandlerRegistration Maven / Gradle / Ivy
/*
* Copyright 2002-2021 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
*
* https://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.List;
import org.springframework.cache.Cache;
import org.springframework.core.io.Resource;
import org.springframework.http.CacheControl;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.servlet.resource.PathResourceResolver;
import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
/**
* Encapsulates information required to create a resource handler.
*
* @author Rossen Stoyanchev
* @author Keith Donald
* @author Brian Clozel
* @since 3.1
*/
public class ResourceHandlerRegistration {
private final String[] pathPatterns;
private final List locationValues = new ArrayList<>();
private final List locationsResources = new ArrayList<>();
@Nullable
private Integer cachePeriod;
@Nullable
private CacheControl cacheControl;
@Nullable
private ResourceChainRegistration resourceChainRegistration;
private boolean useLastModified = true;
private boolean optimizeLocations = false;
/**
* Create a {@link ResourceHandlerRegistration} instance.
* @param pathPatterns one or more resource URL path patterns
*/
public ResourceHandlerRegistration(String... pathPatterns) {
Assert.notEmpty(pathPatterns, "At least one path pattern is required for resource handling.");
this.pathPatterns = pathPatterns;
}
/**
* Add one or more resource locations from which to serve static content.
* Each location must point to a valid directory. Multiple locations may
* be specified as a comma-separated list, and the locations will be checked
* for a given resource in the order specified.
* For example, {{@code "/"}, {@code "classpath:/META-INF/public-web-resources/"}}
* allows resources to be served both from the web application root and
* from any JAR on the classpath that contains a
* {@code /META-INF/public-web-resources/} directory, with resources in the
* web application root taking precedence.
*
For {@link org.springframework.core.io.UrlResource URL-based resources}
* (e.g. files, HTTP URLs, etc) this method supports a special prefix to
* indicate the charset associated with the URL so that relative paths
* appended to it can be encoded correctly, e.g.
* {@code [charset=Windows-31J]https://example.org/path}.
* @return the same {@link ResourceHandlerRegistration} instance, for
* chained method invocation
*/
public ResourceHandlerRegistration addResourceLocations(String... locations) {
this.locationValues.addAll(Arrays.asList(locations));
return this;
}
/**
* Configure locations to serve static resources from based on pre-resolved
* {@code Resource} references.
* @param locations the resource locations to use
* @return the same {@link ResourceHandlerRegistration} instance, for
* chained method invocation
* @since 5.3.3
*/
public ResourceHandlerRegistration addResourceLocations(Resource... locations) {
this.locationsResources.addAll(Arrays.asList(locations));
return this;
}
/**
* Specify the cache period for the resources served by the resource handler, in seconds. The default is to not
* send any cache headers but to rely on last-modified timestamps only. Set to 0 in order to send cache headers
* that prevent caching, or to a positive number of seconds to send cache headers with the given max-age value.
* @param cachePeriod the time to cache resources in seconds
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
*/
public ResourceHandlerRegistration setCachePeriod(Integer cachePeriod) {
this.cachePeriod = cachePeriod;
return this;
}
/**
* Specify the {@link org.springframework.http.CacheControl} which should be used
* by the resource handler.
*
Setting a custom value here will override the configuration set with {@link #setCachePeriod}.
* @param cacheControl the CacheControl configuration to use
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
* @since 4.2
*/
public ResourceHandlerRegistration setCacheControl(CacheControl cacheControl) {
this.cacheControl = cacheControl;
return this;
}
/**
* Set whether the {@link Resource#lastModified()} information should be used to drive HTTP responses.
*
This configuration is set to {@code true} by default.
* @param useLastModified whether the "last modified" resource information should be used
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
* @since 5.3
* @see ResourceHttpRequestHandler#setUseLastModified
*/
public ResourceHandlerRegistration setUseLastModified(boolean useLastModified) {
this.useLastModified = useLastModified;
return this;
}
/**
* Set whether to optimize the specified locations through an existence check on startup,
* filtering non-existing directories upfront so that they do not have to be checked
* on every resource access.
*
The default is {@code false}, for defensiveness against zip files without directory
* entries which are unable to expose the existence of a directory upfront. Switch this flag to
* {@code true} for optimized access in case of a consistent jar layout with directory entries.
* @param optimizeLocations whether to optimize the locations through an existence check on startup
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
* @since 5.3.13
* @see ResourceHttpRequestHandler#setOptimizeLocations
*/
public ResourceHandlerRegistration setOptimizeLocations(boolean optimizeLocations) {
this.optimizeLocations = optimizeLocations;
return this;
}
/**
* Configure a chain of resource resolvers and transformers to use. This
* can be useful, for example, to apply a version strategy to resource URLs.
*
If this method is not invoked, by default only a simple
* {@link PathResourceResolver} is used in order to match URL paths to
* resources under the configured locations.
* @param cacheResources whether to cache the result of resource resolution;
* setting this to "true" is recommended for production (and "false" for
* development, especially when applying a version strategy)
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
* @since 4.1
*/
public ResourceChainRegistration resourceChain(boolean cacheResources) {
this.resourceChainRegistration = new ResourceChainRegistration(cacheResources);
return this.resourceChainRegistration;
}
/**
* Configure a chain of resource resolvers and transformers to use. This
* can be useful, for example, to apply a version strategy to resource URLs.
*
If this method is not invoked, by default only a simple
* {@link PathResourceResolver} is used in order to match URL paths to
* resources under the configured locations.
* @param cacheResources whether to cache the result of resource resolution;
* setting this to "true" is recommended for production (and "false" for
* development, especially when applying a version strategy
* @param cache the cache to use for storing resolved and transformed resources;
* by default a {@link org.springframework.cache.concurrent.ConcurrentMapCache}
* is used. Since Resources aren't serializable and can be dependent on the
* application host, one should not use a distributed cache but rather an
* in-memory cache.
* @return the same {@link ResourceHandlerRegistration} instance, for chained method invocation
* @since 4.1
*/
public ResourceChainRegistration resourceChain(boolean cacheResources, Cache cache) {
this.resourceChainRegistration = new ResourceChainRegistration(cacheResources, cache);
return this.resourceChainRegistration;
}
/**
* Return the URL path patterns for the resource handler.
*/
protected String[] getPathPatterns() {
return this.pathPatterns;
}
/**
* Return a {@link ResourceHttpRequestHandler} instance.
*/
protected ResourceHttpRequestHandler getRequestHandler() {
ResourceHttpRequestHandler handler = new ResourceHttpRequestHandler();
if (this.resourceChainRegistration != null) {
handler.setResourceResolvers(this.resourceChainRegistration.getResourceResolvers());
handler.setResourceTransformers(this.resourceChainRegistration.getResourceTransformers());
}
handler.setLocationValues(this.locationValues);
handler.setLocations(this.locationsResources);
if (this.cacheControl != null) {
handler.setCacheControl(this.cacheControl);
}
else if (this.cachePeriod != null) {
handler.setCacheSeconds(this.cachePeriod);
}
handler.setUseLastModified(this.useLastModified);
handler.setOptimizeLocations(this.optimizeLocations);
return handler;
}
}