org.springframework.web.servlet.resource.ResourceUrlEncodingFilter Maven / Gradle / Ivy
/*
* Copyright 2002-2019 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.resource;
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.lang.Nullable;
import org.springframework.web.filter.GenericFilterBean;
import org.springframework.web.util.UrlPathHelper;
/**
* A filter that wraps the {@link HttpServletResponse} and overrides its
* {@link HttpServletResponse#encodeURL(String) encodeURL} method in order to
* translate internal resource request URLs into public URL paths for external use.
*
* @author Jeremy Grelle
* @author Rossen Stoyanchev
* @author Sam Brannen
* @author Brian Clozel
* @since 4.1
*/
public class ResourceUrlEncodingFilter extends GenericFilterBean {
private static final Log logger = LogFactory.getLog(ResourceUrlEncodingFilter.class);
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
if (!(request instanceof HttpServletRequest) || !(response instanceof HttpServletResponse)) {
throw new ServletException("ResourceUrlEncodingFilter only supports HTTP requests");
}
ResourceUrlEncodingRequestWrapper wrappedRequest =
new ResourceUrlEncodingRequestWrapper((HttpServletRequest) request);
ResourceUrlEncodingResponseWrapper wrappedResponse =
new ResourceUrlEncodingResponseWrapper(wrappedRequest, (HttpServletResponse) response);
filterChain.doFilter(wrappedRequest, wrappedResponse);
}
private static class ResourceUrlEncodingRequestWrapper extends HttpServletRequestWrapper {
@Nullable
private ResourceUrlProvider resourceUrlProvider;
@Nullable
private Integer indexLookupPath;
private String prefixLookupPath = "";
ResourceUrlEncodingRequestWrapper(HttpServletRequest request) {
super(request);
}
@Override
public void setAttribute(String name, Object value) {
super.setAttribute(name, value);
if (ResourceUrlProviderExposingInterceptor.RESOURCE_URL_PROVIDER_ATTR.equals(name)) {
if (value instanceof ResourceUrlProvider) {
initLookupPath((ResourceUrlProvider) value);
}
}
}
private void initLookupPath(ResourceUrlProvider urlProvider) {
this.resourceUrlProvider = urlProvider;
if (this.indexLookupPath == null) {
UrlPathHelper pathHelper = this.resourceUrlProvider.getUrlPathHelper();
String requestUri = pathHelper.getRequestUri(this);
String lookupPath = pathHelper.getLookupPathForRequest(this);
this.indexLookupPath = requestUri.lastIndexOf(lookupPath);
if (this.indexLookupPath == -1) {
throw new LookupPathIndexException(lookupPath, requestUri);
}
this.prefixLookupPath = requestUri.substring(0, this.indexLookupPath);
if ("/".equals(lookupPath) && !"/".equals(requestUri)) {
String contextPath = pathHelper.getContextPath(this);
if (requestUri.equals(contextPath)) {
this.indexLookupPath = requestUri.length();
this.prefixLookupPath = requestUri;
}
}
}
}
@Nullable
public String resolveUrlPath(String url) {
if (this.resourceUrlProvider == null) {
logger.trace("ResourceUrlProvider not available via request attribute " +
ResourceUrlProviderExposingInterceptor.RESOURCE_URL_PROVIDER_ATTR);
return null;
}
if (this.indexLookupPath != null && url.startsWith(this.prefixLookupPath)) {
int suffixIndex = getEndPathIndex(url);
String suffix = url.substring(suffixIndex);
String lookupPath = url.substring(this.indexLookupPath, suffixIndex);
lookupPath = this.resourceUrlProvider.getForLookupPath(lookupPath);
if (lookupPath != null) {
return this.prefixLookupPath + lookupPath + suffix;
}
}
return null;
}
private int getEndPathIndex(String path) {
int end = path.indexOf('?');
int fragmentIndex = path.indexOf('#');
if (fragmentIndex != -1 && (end == -1 || fragmentIndex < end)) {
end = fragmentIndex;
}
if (end == -1) {
end = path.length();
}
return end;
}
}
private static class ResourceUrlEncodingResponseWrapper extends HttpServletResponseWrapper {
private final ResourceUrlEncodingRequestWrapper request;
ResourceUrlEncodingResponseWrapper(ResourceUrlEncodingRequestWrapper request, HttpServletResponse wrapped) {
super(wrapped);
this.request = request;
}
@Override
public String encodeURL(String url) {
String urlPath = this.request.resolveUrlPath(url);
if (urlPath != null) {
return super.encodeURL(urlPath);
}
return super.encodeURL(url);
}
}
/**
* Runtime exception to get far enough (to ResourceUrlProviderExposingInterceptor)
* where it can be re-thrown as ServletRequestBindingException to result in
* a 400 response.
*/
@SuppressWarnings("serial")
static class LookupPathIndexException extends IllegalArgumentException {
LookupPathIndexException(String lookupPath, String requestUri) {
super("Failed to find lookupPath '" + lookupPath + "' within requestUri '" + requestUri + "'. " +
"This could be because the path has invalid encoded characters or isn't normalized.");
}
}
}