/* * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/methods/HeadMethod.java,v 1.29 2004/06/13 20:22:19 olegk Exp $ * $Revision: 480424 $ * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $ * * ==================================================================== * *  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.commons.httpclient.methods;import java.io.IOException;import org.apache.commons.httpclient.HttpConnection;import org.apache.commons.httpclient.HttpException;import org.apache.commons.httpclient.HttpMethodBase;import org.apache.commons.httpclient.HttpState;import org.apache.commons.httpclient.ProtocolException;import org.apache.commons.httpclient.params.HttpMethodParams;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;/** * Implements the HTTP HEAD method. * <p> * The HTTP HEAD method is defined in section 9.4 of  * <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>: * <blockquote> * The HEAD method is identical to GET except that the server MUST NOT * return a message-body in the response. The metainformation contained * in the HTTP headers in response to a HEAD request SHOULD be identical * to the information sent in response to a GET request. This method can * be used for obtaining metainformation about the entity implied by the * request without transferring the entity-body itself. This method is * often used for testing hypertext links for validity, accessibility, * and recent modification. * </blockquote> * </p> *  * @author <a href="mailto:remm@apache.org">Remy Maucherat</a> * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a> * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a> * @author <a href="mailto:oleg@ural.ru">oleg Kalnichevski</a> * * @version $Revision: 480424 $ * @since 1.0 */public class HeadMethod extends HttpMethodBase {    //~ Static variables/initializers    /** Log object for this class. */    private static final Log LOG = LogFactory.getLog(HeadMethod.class);    //~ Constructors    /**     * No-arg constructor.     *      * @since 1.0     */    public HeadMethod() {        setFollowRedirects(true);    }    /**     * Constructor specifying a URI.     *     * @param uri either an absolute or relative URI     *      * @since 1.0     */    public HeadMethod(String uri) {        super(uri);        setFollowRedirects(true);    }    //~ Methods    /**     * Returns <tt>"HEAD"</tt>.     *      * @return <tt>"HEAD"</tt>     *      * @since 2.0     */    public String getName() {        return "HEAD";    }    /**     * Recycles the HTTP method so that it can be used again.     * Note that all of the instance variables will be reset     * once this method has been called. This method will also     * release the connection being used by this HTTP method.     *      * @see #releaseConnection()     *      * @since 1.0     *      * @deprecated no longer supported and will be removed in the future     *             version of HttpClient     */    public void recycle() {        super.recycle();        setFollowRedirects(true);    }    /**     * Overrides {@link HttpMethodBase} method to <i>not</i> read a response     * body, despite the presence of a <tt>Content-Length</tt> or     * <tt>Transfer-Encoding</tt> header.     *      * @param state the {@link HttpState state} information associated with this method     * @param conn the {@link HttpConnection connection} used to execute     *        this HTTP method     *     * @throws IOException if an I/O (transport) error occurs. Some transport exceptions     *                     can be recovered from.     * @throws HttpException  if a protocol exception occurs. Usually protocol exceptions      *                    cannot be recovered from.     *     * @see #readResponse     * @see #processResponseBody     *      * @since 2.0     */    protected void readResponseBody(HttpState state, HttpConnection conn)    throws HttpException, IOException {        LOG.trace(            "enter HeadMethod.readResponseBody(HttpState, HttpConnection)");                int bodyCheckTimeout =             getParams().getIntParameter(HttpMethodParams.HEAD_BODY_CHECK_TIMEOUT, -1);        if (bodyCheckTimeout < 0) {            responseBodyConsumed();        } else {            if (LOG.isDebugEnabled()) {                LOG.debug("Check for non-compliant response body. Timeout in "                  + bodyCheckTimeout + " ms");                }            boolean responseAvailable = false;            try {                responseAvailable = conn.isResponseAvailable(bodyCheckTimeout);            } catch (IOException e) {                LOG.debug("An IOException occurred while testing if a response was available,"                    + " we will assume one is not.",                     e);                responseAvailable = false;            }            if (responseAvailable) {                if (getParams().isParameterTrue(HttpMethodParams.REJECT_HEAD_BODY)) {                    throw new ProtocolException(                        "Body content may not be sent in response to HTTP HEAD request");                } else {                    LOG.warn("Body content returned in response to HTTP HEAD");                    }                super.readResponseBody(state, conn);            }        }    }        /**     * Returns non-compliant response body check timeout.     *      * @return The period of time in milliseconds to wait for a response      *         body from a non-compliant server. <tt>-1</tt> returned when      *         non-compliant response body check is disabled     *      * @deprecated Use {@link HttpMethodParams}     *      * @see #getParams()     * @see HttpMethodParams     * @see HttpMethodParams#HEAD_BODY_CHECK_TIMEOUT     */    public int getBodyCheckTimeout() {        return getParams().getIntParameter(HttpMethodParams.HEAD_BODY_CHECK_TIMEOUT, -1);    }    /**     * Sets non-compliant response body check timeout.     *      * @param timeout The period of time in milliseconds to wait for a response      *         body from a non-compliant server. <tt>-1</tt> can be used to      *         disable non-compliant response body check     *       * @deprecated Use {@link HttpMethodParams}     *      * @see #getParams()     * @see HttpMethodParams     * @see HttpMethodParams#HEAD_BODY_CHECK_TIMEOUT     */    public void setBodyCheckTimeout(int timeout) {        getParams().setIntParameter(HttpMethodParams.HEAD_BODY_CHECK_TIMEOUT, timeout);    }}