Java tutorial
/* * ==================================================================== * 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.apache.http.impl.client.cache; import java.util.concurrent.ExecutionException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpHost; import org.apache.http.HttpResponse; import org.apache.http.ProtocolException; import org.apache.http.client.cache.HttpCacheContext; import org.apache.http.client.cache.HttpCacheEntry; import org.apache.http.client.methods.HttpRequestWrapper; import org.apache.http.concurrent.BasicFuture; import org.apache.http.concurrent.FutureCallback; /** * Class used to represent an asynchronous revalidation event, such as with * "stale-while-revalidate" */ class AsynchronousAsyncValidationRequest implements Runnable { private final AsynchronousAsyncValidator parent; private final CachingHttpAsyncClient cachingAsyncClient; private final HttpHost target; private final HttpRequestWrapper request; private final HttpCacheContext clientContext; private final HttpCacheEntry cacheEntry; private final String identifier; private final Log log = LogFactory.getLog(getClass()); /** * Used internally by {@link AsynchronousValidator} to schedule a * revalidation. */ AsynchronousAsyncValidationRequest(final AsynchronousAsyncValidator parent, final CachingHttpAsyncClient cachingClient, final HttpHost target, final HttpRequestWrapper request, final HttpCacheContext clientContext, final HttpCacheEntry cacheEntry, final String identifier) { this.parent = parent; this.cachingAsyncClient = cachingClient; this.target = target; this.request = request; this.clientContext = clientContext; this.cacheEntry = cacheEntry; this.identifier = identifier; } @Override public void run() { try { final FutureCallback<HttpResponse> callback = new FutureCallback<HttpResponse>() { @Override public void cancelled() { } @Override public void completed(final HttpResponse httpResponse) { } @Override public void failed(final Exception e) { log.debug("Asynchronous revalidation failed", e); } }; final BasicFuture<HttpResponse> future = new BasicFuture<HttpResponse>(callback); this.cachingAsyncClient.revalidateCacheEntry(future, this.target, this.request, this.clientContext, this.cacheEntry); future.get(); } catch (final ProtocolException pe) { this.log.error("ProtocolException thrown during asynchronous revalidation", pe); } catch (final ExecutionException e) { this.log.error("Exception thrown during asynchronous revalidation", e.getCause()); } catch (final InterruptedException e) { Thread.currentThread().interrupt(); } finally { this.parent.markComplete(this.identifier); } } String getIdentifier() { return this.identifier; } }