/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apach3.http.impl.client.cache;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.ListIterator;
import org.apach3.http.Header;
import org.apach3.http.HttpResponse;
import org.apach3.http.HttpStatus;
import org.apach3.http.annotation.Immutable;
import org.apach3.http.client.cache.HeaderConstants;
import org.apach3.http.client.cache.HttpCacheEntry;
import org.apach3.http.client.cache.Resource;
import org.apach3.http.client.cache.ResourceFactory;
import org.apach3.http.impl.cookie.DateParseException;
import org.apach3.http.impl.cookie.DateUtils;
import org.apach3.http.protocol.HTTP;
/**
* Update a {@link HttpCacheEntry} with new or updated information based on the latest
* 304 status response from the Server. Use the {@link HttpResponse} to perform
* the update.
*
* @since 4.1
*/
@Immutable
class CacheEntryUpdater {
private final ResourceFactory resourceFactory;
CacheEntryUpdater() {
this(new HeapResourceFactory());
}
CacheEntryUpdater(final ResourceFactory resourceFactory) {
super();
this.resourceFactory = resourceFactory;
}
/**
* Update the entry with the new information from the response. Should only be used for
* 304 responses.
*
* @param requestId
* @param entry The cache Entry to be updated
* @param requestDate When the request was performed
* @param responseDate When the response was gotten
* @param response The HttpResponse from the backend server call
* @return HttpCacheEntry an updated version of the cache entry
* @throws java.io.IOException if something bad happens while trying to read the body from the original entry
*/
public HttpCacheEntry updateCacheEntry(
String requestId,
HttpCacheEntry entry,
Date requestDate,
Date responseDate,
HttpResponse response) throws IOException {
if (response.getStatusLine().getStatusCode() != HttpStatus.SC_NOT_MODIFIED)
throw new IllegalArgumentException("Response must have 304 status code");
Header[] mergedHeaders = mergeHeaders(entry, response);
Resource resource = resourceFactory.copy(requestId, entry.getResource());
return new HttpCacheEntry(
requestDate,
responseDate,
entry.getStatusLine(),
mergedHeaders,
resource);
}
protected Header[] mergeHeaders(HttpCacheEntry entry, HttpResponse response) {
if (entryAndResponseHaveDateHeader(entry, response)
&& entryDateHeaderNewerThenResponse(entry, response)) {
// Don't merge headers, keep the entry's headers as they are newer.
return entry.getAllHeaders();
}
List<Header> cacheEntryHeaderList = new ArrayList<Header>(Arrays.asList(entry
.getAllHeaders()));
removeCacheHeadersThatMatchResponse(cacheEntryHeaderList, response);
removeCacheEntry1xxWarnings(cacheEntryHeaderList, entry);
cacheEntryHeaderList.addAll(Arrays.asList(response.getAllHeaders()));
return cacheEntryHeaderList.toArray(new Header[cacheEntryHeaderList.size()]);
}
private void removeCacheHeadersThatMatchResponse(List<Header> cacheEntryHeaderList,
HttpResponse response) {
for (Header responseHeader : response.getAllHeaders()) {
ListIterator<Header> cacheEntryHeaderListIter = cacheEntryHeaderList.listIterator();
while (cacheEntryHeaderListIter.hasNext()) {
String cacheEntryHeaderName = cacheEntryHeaderListIter.next().getName();
if (cacheEntryHeaderName.equals(responseHeader.getName())) {
cacheEntryHeaderListIter.remove();
}
}
}
}
private void removeCacheEntry1xxWarnings(List<Header> cacheEntryHeaderList, HttpCacheEntry entry) {
ListIterator<Header> cacheEntryHeaderListIter = cacheEntryHeaderList.listIterator();
while (cacheEntryHeaderListIter.hasNext()) {
String cacheEntryHeaderName = cacheEntryHeaderListIter.next().getName();
if (HeaderConstants.WARNING.equals(cacheEntryHeaderName)) {
for (Header cacheEntryWarning : entry.getHeaders(HeaderConstants.WARNING)) {
if (cacheEntryWarning.getValue().startsWith("1")) {
cacheEntryHeaderListIter.remove();
}
}
}
}
}
private boolean entryDateHeaderNewerThenResponse(HttpCacheEntry entry, HttpResponse response) {
try {
Date entryDate = DateUtils.parseDate(entry.getFirstHeader(HTTP.DATE_HEADER)
.getValue());
Date responseDate = DateUtils.parseDate(response.getFirstHeader(HTTP.DATE_HEADER)
.getValue());
if (!entryDate.after(responseDate)) {
return false;
}
} catch (DateParseException e) {
return false;
}
return true;
}
private boolean entryAndResponseHaveDateHeader(HttpCacheEntry entry, HttpResponse response) {
if (entry.getFirstHeader(HTTP.DATE_HEADER) != null
&& response.getFirstHeader(HTTP.DATE_HEADER) != null) {
return true;
}
return false;
}
}