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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/>.
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package org.apache.http.impl.execchain;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpClientConnection;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.ProtocolException;
import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpExecutionAware;
import org.apache.http.client.methods.HttpRequestWrapper;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.client.protocol.RequestClientConnControl;
import org.apache.http.client.utils.URIUtils;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.conn.ConnectionRequest;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.impl.conn.ConnectionShutdownException;
import org.apache.http.protocol.HttpCoreContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.HttpRequestExecutor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.RequestContent;
import org.apache.http.protocol.RequestTargetHost;
import org.apache.http.protocol.RequestUserAgent;
import org.apache.http.util.Args;
import org.apache.http.util.VersionInfo;

Request executor that implements the most fundamental aspects of the HTTP specification and the most straight-forward request / response exchange with the target server. This executor does not support execution via proxy and will make no attempts to retry the request in case of a redirect, authentication challenge or I/O error.
Since:4.3
/** * Request executor that implements the most fundamental aspects of * the HTTP specification and the most straight-forward request / response * exchange with the target server. This executor does not support * execution via proxy and will make no attempts to retry the request * in case of a redirect, authentication challenge or I/O error. * * @since 4.3 */
@Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL) public class MinimalClientExec implements ClientExecChain { private final Log log = LogFactory.getLog(getClass()); private final HttpRequestExecutor requestExecutor; private final HttpClientConnectionManager connManager; private final ConnectionReuseStrategy reuseStrategy; private final ConnectionKeepAliveStrategy keepAliveStrategy; private final HttpProcessor httpProcessor; public MinimalClientExec( final HttpRequestExecutor requestExecutor, final HttpClientConnectionManager connManager, final ConnectionReuseStrategy reuseStrategy, final ConnectionKeepAliveStrategy keepAliveStrategy) { Args.notNull(requestExecutor, "HTTP request executor"); Args.notNull(connManager, "Client connection manager"); Args.notNull(reuseStrategy, "Connection reuse strategy"); Args.notNull(keepAliveStrategy, "Connection keep alive strategy"); this.httpProcessor = new ImmutableHttpProcessor( new RequestContent(), new RequestTargetHost(), new RequestClientConnControl(), new RequestUserAgent(VersionInfo.getUserAgent( "Apache-HttpClient", "org.apache.http.client", getClass()))); this.requestExecutor = requestExecutor; this.connManager = connManager; this.reuseStrategy = reuseStrategy; this.keepAliveStrategy = keepAliveStrategy; } static void rewriteRequestURI( final HttpRequestWrapper request, final HttpRoute route) throws ProtocolException { try { URI uri = request.getURI(); if (uri != null) { // Make sure the request URI is relative if (uri.isAbsolute()) { uri = URIUtils.rewriteURI(uri, null, true); } else { uri = URIUtils.rewriteURI(uri); } request.setURI(uri); } } catch (final URISyntaxException ex) { throw new ProtocolException("Invalid URI: " + request.getRequestLine().getUri(), ex); } } @Override public CloseableHttpResponse execute( final HttpRoute route, final HttpRequestWrapper request, final HttpClientContext context, final HttpExecutionAware execAware) throws IOException, HttpException { Args.notNull(route, "HTTP route"); Args.notNull(request, "HTTP request"); Args.notNull(context, "HTTP context"); rewriteRequestURI(request, route); final ConnectionRequest connRequest = connManager.requestConnection(route, null); if (execAware != null) { if (execAware.isAborted()) { connRequest.cancel(); throw new RequestAbortedException("Request aborted"); } execAware.setCancellable(connRequest); } final RequestConfig config = context.getRequestConfig(); final HttpClientConnection managedConn; try { final int timeout = config.getConnectionRequestTimeout(); managedConn = connRequest.get(timeout > 0 ? timeout : 0, TimeUnit.MILLISECONDS); } catch(final InterruptedException interrupted) { Thread.currentThread().interrupt(); throw new RequestAbortedException("Request aborted", interrupted); } catch(final ExecutionException ex) { Throwable cause = ex.getCause(); if (cause == null) { cause = ex; } throw new RequestAbortedException("Request execution failed", cause); } final ConnectionHolder releaseTrigger = new ConnectionHolder(log, connManager, managedConn); try { if (execAware != null) { if (execAware.isAborted()) { releaseTrigger.close(); throw new RequestAbortedException("Request aborted"); } execAware.setCancellable(releaseTrigger); } if (!managedConn.isOpen()) { final int timeout = config.getConnectTimeout(); this.connManager.connect( managedConn, route, timeout > 0 ? timeout : 0, context); this.connManager.routeComplete(managedConn, route, context); } final int timeout = config.getSocketTimeout(); if (timeout >= 0) { managedConn.setSocketTimeout(timeout); } HttpHost target = null; final HttpRequest original = request.getOriginal(); if (original instanceof HttpUriRequest) { final URI uri = ((HttpUriRequest) original).getURI(); if (uri.isAbsolute()) { target = new HttpHost(uri.getHost(), uri.getPort(), uri.getScheme()); } } if (target == null) { target = route.getTargetHost(); } context.setAttribute(HttpCoreContext.HTTP_TARGET_HOST, target); context.setAttribute(HttpCoreContext.HTTP_REQUEST, request); context.setAttribute(HttpCoreContext.HTTP_CONNECTION, managedConn); context.setAttribute(HttpClientContext.HTTP_ROUTE, route); httpProcessor.process(request, context); final HttpResponse response = requestExecutor.execute(request, managedConn, context); httpProcessor.process(response, context); // The connection is in or can be brought to a re-usable state. if (reuseStrategy.keepAlive(response, context)) { // Set the idle duration of this connection final long duration = keepAliveStrategy.getKeepAliveDuration(response, context); releaseTrigger.setValidFor(duration, TimeUnit.MILLISECONDS); releaseTrigger.markReusable(); } else { releaseTrigger.markNonReusable(); } // check for entity, release connection if possible final HttpEntity entity = response.getEntity(); if (entity == null || !entity.isStreaming()) { // connection not needed and (assumed to be) in re-usable state releaseTrigger.releaseConnection(); return new HttpResponseProxy(response, null); } return new HttpResponseProxy(response, releaseTrigger); } catch (final ConnectionShutdownException ex) { final InterruptedIOException ioex = new InterruptedIOException( "Connection has been shut down"); ioex.initCause(ex); throw ioex; } catch (final HttpException ex) { releaseTrigger.abortConnection(); throw ex; } catch (final IOException ex) { releaseTrigger.abortConnection(); throw ex; } catch (final RuntimeException ex) { releaseTrigger.abortConnection(); throw ex; } catch (final Error error) { connManager.shutdown(); throw error; } } }