/*
* $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.
The HTTP HEAD method is defined in section 9.4 of
RFC2616:
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.
Author: Remy Maucherat, Mike Bowler, Jeff Dever, oleg Kalnichevski Version: $Revision: 480424 $ Since: 1.0
/**
* 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. /** Log object for this class. */
private static final Log LOG = LogFactory.getLog(HeadMethod.class);
//~ Constructors
No-arg constructor.
Since: 1.0
/**
* No-arg constructor.
*
* @since 1.0
*/
public HeadMethod() {
setFollowRedirects(true);
}
Constructor specifying a URI.
Params: - uri – either an absolute or relative URI
Since: 1.0
/**
* 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 "HEAD".
Returns: "HEAD" Since: 2.0
/**
* 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 Also: - releaseConnection()
Since: 1.0 Deprecated: no longer supported and will be removed in the future
version of HttpClient
/**
* 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 HttpMethodBase method to not read a response
body, despite the presence of a Content-Length or
Transfer-Encoding header.
Params: - state – the
state information associated with this method - conn – the
connection used to execute this HTTP method
Throws: - IOException – if an I/O (transport) error occurs. Some transport exceptions
can be recovered from.
- HttpException – if a protocol exception occurs. Usually protocol exceptions
cannot be recovered from.
See Also: Since: 2.0
/**
* 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.
See Also: Returns: The period of time in milliseconds to wait for a response
body from a non-compliant server. -1 returned when
non-compliant response body check is disabled Deprecated: Use HttpMethodParams
/**
* 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.
Params: - timeout – The period of time in milliseconds to wait for a response
body from a non-compliant server. -1 can be used to
disable non-compliant response body check
See Also: Deprecated: Use HttpMethodParams
/**
* 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);
}
}