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/*
* ====================================================================
* 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 ch.boye.httpclientandroidlib.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 ch.boye.httpclientandroidlib.Header;
import ch.boye.httpclientandroidlib.HttpResponse;
import ch.boye.httpclientandroidlib.HttpStatus;
import ch.boye.httpclientandroidlib.annotation.Immutable;
import ch.boye.httpclientandroidlib.client.cache.HeaderConstants;
import ch.boye.httpclientandroidlib.client.cache.HttpCacheEntry;
import ch.boye.httpclientandroidlib.client.cache.Resource;
import ch.boye.httpclientandroidlib.client.cache.ResourceFactory;
import ch.boye.httpclientandroidlib.client.utils.DateUtils;
import ch.boye.httpclientandroidlib.protocol.HTTP;
import ch.boye.httpclientandroidlib.util.Args;
/**
* 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(
final String requestId,
final HttpCacheEntry entry,
final Date requestDate,
final Date responseDate,
final HttpResponse response) throws IOException {
Args.check(response.getStatusLine().getStatusCode() == HttpStatus.SC_NOT_MODIFIED,
"Response must have 304 status code");
final Header[] mergedHeaders = mergeHeaders(entry, response);
Resource resource = null;
if (entry.getResource() != null) {
resource = resourceFactory.copy(requestId, entry.getResource());
}
return new HttpCacheEntry(
requestDate,
responseDate,
entry.getStatusLine(),
mergedHeaders,
resource);
}
protected Header[] mergeHeaders(final HttpCacheEntry entry, final 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();
}
final 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(final List<Header> cacheEntryHeaderList,
final HttpResponse response) {
for (final Header responseHeader : response.getAllHeaders()) {
final ListIterator<Header> cacheEntryHeaderListIter = cacheEntryHeaderList.listIterator();
while (cacheEntryHeaderListIter.hasNext()) {
final String cacheEntryHeaderName = cacheEntryHeaderListIter.next().getName();
if (cacheEntryHeaderName.equals(responseHeader.getName())) {
cacheEntryHeaderListIter.remove();
}
}
}
}
private void removeCacheEntry1xxWarnings(final List<Header> cacheEntryHeaderList, final HttpCacheEntry entry) {
final ListIterator<Header> cacheEntryHeaderListIter = cacheEntryHeaderList.listIterator();
while (cacheEntryHeaderListIter.hasNext()) {
final String cacheEntryHeaderName = cacheEntryHeaderListIter.next().getName();
if (HeaderConstants.WARNING.equals(cacheEntryHeaderName)) {
for (final Header cacheEntryWarning : entry.getHeaders(HeaderConstants.WARNING)) {
if (cacheEntryWarning.getValue().startsWith("1")) {
cacheEntryHeaderListIter.remove();
}
}
}
}
}
private boolean entryDateHeaderNewerThenResponse(final HttpCacheEntry entry, final HttpResponse response) {
final Date entryDate = DateUtils.parseDate(entry.getFirstHeader(HTTP.DATE_HEADER)
.getValue());
final Date responseDate = DateUtils.parseDate(response.getFirstHeader(HTTP.DATE_HEADER)
.getValue());
if (entryDate == null || responseDate == null) {
return false;
}
if (!entryDate.after(responseDate)) {
return false;
}
return true;
}
private boolean entryAndResponseHaveDateHeader(final HttpCacheEntry entry, final HttpResponse response) {
if (entry.getFirstHeader(HTTP.DATE_HEADER) != null
&& response.getFirstHeader(HTTP.DATE_HEADER) != null) {
return true;
}
return false;
}
}
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