Java tutorial
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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.HC4.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.HC4.ConnectionReuseStrategy; import org.apache.http.HC4.HttpClientConnection; import org.apache.http.HC4.HttpEntity; import org.apache.http.HC4.HttpException; import org.apache.http.HC4.HttpHost; import org.apache.http.HC4.HttpRequest; import org.apache.http.HC4.HttpResponse; import org.apache.http.HC4.ProtocolException; import org.apache.http.HC4.annotation.Immutable; import org.apache.http.HC4.client.config.RequestConfig; import org.apache.http.HC4.client.methods.CloseableHttpResponse; import org.apache.http.HC4.client.methods.HttpExecutionAware; import org.apache.http.HC4.client.methods.HttpRequestWrapper; import org.apache.http.HC4.client.protocol.HttpClientContext; import org.apache.http.HC4.client.protocol.RequestClientConnControl; import org.apache.http.HC4.conn.ConnectionRequest; import org.apache.http.HC4.conn.HttpClientConnectionManager; import org.apache.http.HC4.impl.conn.ConnectionShutdownException; import org.apache.http.HC4.protocol.HttpCoreContext; import org.apache.http.HC4.protocol.ImmutableHttpProcessor; import org.apache.http.HC4.util.Args; import org.apache.http.HC4.client.methods.HttpUriRequest; import org.apache.http.HC4.client.utils.URIUtils; import org.apache.http.HC4.conn.ConnectionKeepAliveStrategy; import org.apache.http.HC4.conn.routing.HttpRoute; import org.apache.http.HC4.protocol.HttpProcessor; import org.apache.http.HC4.protocol.HttpRequestExecutor; import org.apache.http.HC4.protocol.RequestContent; import org.apache.http.HC4.protocol.RequestTargetHost; import org.apache.http.HC4.protocol.RequestUserAgent; import org.apache.http.HC4.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 */ @Immutable 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"); } else { 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"); } else { 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); } else { 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; } } }