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.impl.conn; import java.io.IOException; import java.net.ConnectException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Socket; import java.net.UnknownHostException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpHost; import org.apache.http.annotation.ThreadSafe; import org.apache.http.client.protocol.ClientContext; import org.apache.http.conn.ClientConnectionOperator; import org.apache.http.conn.ConnectTimeoutException; import org.apache.http.conn.DnsResolver; import org.apache.http.conn.HttpInetSocketAddress; import org.apache.http.conn.OperatedClientConnection; import org.apache.http.conn.scheme.Scheme; import org.apache.http.conn.scheme.SchemeLayeredSocketFactory; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.conn.scheme.SchemeSocketFactory; import org.apache.http.params.HttpConnectionParams; import org.apache.http.params.HttpParams; import org.apache.http.protocol.HttpContext; import org.apache.http.util.Args; import org.apache.http.util.Asserts; /** * Default implementation of a {@link ClientConnectionOperator}. It uses a {@link SchemeRegistry} * to look up {@link SchemeSocketFactory} objects. * <p> * This connection operator is multihome network aware and will attempt to retry failed connects * against all known IP addresses sequentially until the connect is successful or all known * addresses fail to respond. Please note the same * {@link org.apache.http.params.CoreConnectionPNames#CONNECTION_TIMEOUT} value will be used * for each connection attempt, so in the worst case the total elapsed time before timeout * can be <code>CONNECTION_TIMEOUT * n</code> where <code>n</code> is the number of IP addresses * of the given host. One can disable multihome support by overriding * the {@link #resolveHostname(String)} method and returning only one IP address for the given * host name. * <p> * The following parameters can be used to customize the behavior of this * class: * <ul> * <li>{@link org.apache.http.params.CoreProtocolPNames#HTTP_ELEMENT_CHARSET}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#SO_TIMEOUT}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#SO_LINGER}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#SO_REUSEADDR}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#TCP_NODELAY}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#SOCKET_BUFFER_SIZE}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#CONNECTION_TIMEOUT}</li> * <li>{@link org.apache.http.params.CoreConnectionPNames#MAX_LINE_LENGTH}</li> * </ul> * * @since 4.0 * * @deprecated (4.3) use {@link PoolingHttpClientConnectionManager}. */ @Deprecated @ThreadSafe public class DefaultClientConnectionOperator implements ClientConnectionOperator { private final Log log = LogFactory.getLog(getClass()); /** The scheme registry for looking up socket factories. */ protected final SchemeRegistry schemeRegistry; // @ThreadSafe /** the custom-configured DNS lookup mechanism. */ protected final DnsResolver dnsResolver; /** * Creates a new client connection operator for the given scheme registry. * * @param schemes the scheme registry * * @since 4.2 */ public DefaultClientConnectionOperator(final SchemeRegistry schemes) { Args.notNull(schemes, "Scheme registry"); this.schemeRegistry = schemes; this.dnsResolver = new SystemDefaultDnsResolver(); } /** * Creates a new client connection operator for the given scheme registry * and the given custom DNS lookup mechanism. * * @param schemes * the scheme registry * @param dnsResolver * the custom DNS lookup mechanism */ public DefaultClientConnectionOperator(final SchemeRegistry schemes, final DnsResolver dnsResolver) { Args.notNull(schemes, "Scheme registry"); Args.notNull(dnsResolver, "DNS resolver"); this.schemeRegistry = schemes; this.dnsResolver = dnsResolver; } public OperatedClientConnection createConnection() { return new DefaultClientConnection(); } private SchemeRegistry getSchemeRegistry(final HttpContext context) { SchemeRegistry reg = (SchemeRegistry) context.getAttribute(ClientContext.SCHEME_REGISTRY); if (reg == null) { reg = this.schemeRegistry; } return reg; } public void openConnection(final OperatedClientConnection conn, final HttpHost target, final InetAddress local, final HttpContext context, final HttpParams params) throws IOException { Args.notNull(conn, "Connection"); Args.notNull(target, "Target host"); Args.notNull(params, "HTTP parameters"); Asserts.check(!conn.isOpen(), "Connection must not be open"); final SchemeRegistry registry = getSchemeRegistry(context); final Scheme schm = registry.getScheme(target.getSchemeName()); final SchemeSocketFactory sf = schm.getSchemeSocketFactory(); final InetAddress[] addresses = resolveHostname(target.getHostName()); final int port = schm.resolvePort(target.getPort()); for (int i = 0; i < addresses.length; i++) { final InetAddress address = addresses[i]; final boolean last = i == addresses.length - 1; Socket sock = sf.createSocket(params); conn.opening(sock, target); final InetSocketAddress remoteAddress = new HttpInetSocketAddress(target, address, port); InetSocketAddress localAddress = null; if (local != null) { localAddress = new InetSocketAddress(local, 0); } if (this.log.isDebugEnabled()) { this.log.debug("Connecting to " + remoteAddress); } try { final Socket connsock = sf.connectSocket(sock, remoteAddress, localAddress, params); if (sock != connsock) { sock = connsock; conn.opening(sock, target); } prepareSocket(sock, context, params); conn.openCompleted(sf.isSecure(sock), params); return; } catch (final ConnectException ex) { if (last) { throw ex; } } catch (final ConnectTimeoutException ex) { if (last) { throw ex; } } if (this.log.isDebugEnabled()) { this.log.debug("Connect to " + remoteAddress + " timed out. " + "Connection will be retried using another IP address"); } } } public void updateSecureConnection(final OperatedClientConnection conn, final HttpHost target, final HttpContext context, final HttpParams params) throws IOException { Args.notNull(conn, "Connection"); Args.notNull(target, "Target host"); Args.notNull(params, "Parameters"); Asserts.check(conn.isOpen(), "Connection must be open"); final SchemeRegistry registry = getSchemeRegistry(context); final Scheme schm = registry.getScheme(target.getSchemeName()); Asserts.check(schm.getSchemeSocketFactory() instanceof SchemeLayeredSocketFactory, "Socket factory must implement SchemeLayeredSocketFactory"); final SchemeLayeredSocketFactory lsf = (SchemeLayeredSocketFactory) schm.getSchemeSocketFactory(); final Socket sock = lsf.createLayeredSocket(conn.getSocket(), target.getHostName(), schm.resolvePort(target.getPort()), params); prepareSocket(sock, context, params); conn.update(sock, target, lsf.isSecure(sock), params); } /** * Performs standard initializations on a newly created socket. * * @param sock the socket to prepare * @param context the context for the connection * @param params the parameters from which to prepare the socket * * @throws IOException in case of an IO problem */ protected void prepareSocket(final Socket sock, final HttpContext context, final HttpParams params) throws IOException { sock.setTcpNoDelay(HttpConnectionParams.getTcpNoDelay(params)); sock.setSoTimeout(HttpConnectionParams.getSoTimeout(params)); final int linger = HttpConnectionParams.getLinger(params); if (linger >= 0) { sock.setSoLinger(linger > 0, linger); } } /** * Resolves the given host name to an array of corresponding IP addresses, based on the * configured name service on the provided DNS resolver. If one wasn't provided, the system * configuration is used. * * @param host host name to resolve * @return array of IP addresses * @exception UnknownHostException if no IP address for the host could be determined. * * @see DnsResolver * @see SystemDefaultDnsResolver * * @since 4.1 */ protected InetAddress[] resolveHostname(final String host) throws UnknownHostException { return dnsResolver.resolve(host); } }