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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 ch.boye.httpclientandroidlib.androidextra.HttpClientAndroidLog;
/* LogFactory removed by HttpClient for Android script. */
import ch.boye.httpclientandroidlib.Header;
import ch.boye.httpclientandroidlib.HttpException;
import ch.boye.httpclientandroidlib.HttpResponse;
import ch.boye.httpclientandroidlib.client.cache.HeaderConstants;
import ch.boye.httpclientandroidlib.client.cache.HttpCacheEntry;
import ch.boye.httpclientandroidlib.client.methods.HttpExecutionAware;
import ch.boye.httpclientandroidlib.client.methods.HttpRequestWrapper;
import ch.boye.httpclientandroidlib.client.methods.CloseableHttpResponse;
import ch.boye.httpclientandroidlib.client.protocol.HttpClientContext;
import ch.boye.httpclientandroidlib.conn.routing.HttpRoute;
/**
* Class used to represent an asynchronous revalidation event, such as with
* "stale-while-revalidate"
*/
class AsynchronousValidationRequest implements Runnable {
private final AsynchronousValidator parent;
private final CachingExec cachingExec;
private final HttpRoute route;
private final HttpRequestWrapper request;
private final HttpClientContext context;
private final HttpExecutionAware execAware;
private final HttpCacheEntry cacheEntry;
private final String identifier;
private final int consecutiveFailedAttempts;
public HttpClientAndroidLog log = new HttpClientAndroidLog(getClass());
/**
* Used internally by {@link AsynchronousValidator} to schedule a
* revalidation.
* @param request
* @param context
* @param cacheEntry
* @param identifier
* @param consecutiveFailedAttempts
*/
AsynchronousValidationRequest(
final AsynchronousValidator parent,
final CachingExec cachingExec,
final HttpRoute route,
final HttpRequestWrapper request,
final HttpClientContext context,
final HttpExecutionAware execAware,
final HttpCacheEntry cacheEntry,
final String identifier,
final int consecutiveFailedAttempts) {
this.parent = parent;
this.cachingExec = cachingExec;
this.route = route;
this.request = request;
this.context = context;
this.execAware = execAware;
this.cacheEntry = cacheEntry;
this.identifier = identifier;
this.consecutiveFailedAttempts = consecutiveFailedAttempts;
}
public void run() {
try {
if (revalidateCacheEntry()) {
parent.jobSuccessful(identifier);
} else {
parent.jobFailed(identifier);
}
} finally {
parent.markComplete(identifier);
}
}
/**
* Revalidate the cache entry and return if the operation was successful.
* Success means a connection to the server was established and replay did
* not indicate a server error.
* @return <code>true</code> if the cache entry was successfully validated;
* otherwise <code>false</code>
*/
protected boolean revalidateCacheEntry() {
try {
final CloseableHttpResponse httpResponse = cachingExec.revalidateCacheEntry(route, request, context, execAware, cacheEntry);
try {
final int statusCode = httpResponse.getStatusLine().getStatusCode();
return isNotServerError(statusCode) && isNotStale(httpResponse);
} finally {
httpResponse.close();
}
} catch (final IOException ioe) {
log.debug("Asynchronous revalidation failed due to I/O error", ioe);
return false;
} catch (final HttpException pe) {
log.error("HTTP protocol exception during asynchronous revalidation", pe);
return false;
} catch (final RuntimeException re) {
log.error("RuntimeException thrown during asynchronous revalidation: " + re);
return false;
}
}
/**
* Return whether the status code indicates a server error or not.
* @param statusCode the status code to be checked
* @return if the status code indicates a server error or not
*/
private boolean isNotServerError(final int statusCode) {
return statusCode < 500;
}
/**
* Try to detect if the returned response is generated from a stale cache entry.
* @param httpResponse the response to be checked
* @return whether the response is stale or not
*/
private boolean isNotStale(final HttpResponse httpResponse) {
final Header[] warnings = httpResponse.getHeaders(HeaderConstants.WARNING);
if (warnings != null)
{
for (final Header warning : warnings)
{
/**
* warn-codes
* 110 = Response is stale
* 111 = Revalidation failed
*/
final String warningValue = warning.getValue();
if (warningValue.startsWith("110") || warningValue.startsWith("111"))
{
return false;
}
}
}
return true;
}
String getIdentifier() {
return identifier;
}
/**
* The number of consecutively failed revalidation attempts.
* @return the number of consecutively failed revalidation attempts.
*/
public int getConsecutiveFailedAttempts() {
return consecutiveFailedAttempts;
}
}
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