/*
* $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/methods/HeadMethod.java,v 1.19.2.2 2003/09/10 21:34:11 mbecke Exp $
* $Revision: 1.19.2.2 $
* $Date: 2003/09/10 21:34:11 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
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* distribution.
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* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
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* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
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* 5. Products derived from this software may not be called "Apache"
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* This software consists of voluntary contributions made by many
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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.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
* @author Mike Bowler
* @author Jeff Dever
* @author oleg Kalnichevski
*
* @version $Revision: 1.19.2.2 $
* @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);
private int bodyCheckTimeout = -1; /* Disabled per default */
//~ 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 "HEAD".
*
* @return "HEAD"
*
* @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
*/
public void recycle() {
super.recycle();
setFollowRedirects(true);
}
/**
* Overrides {@link HttpMethodBase} method to not read a response
* body, despite the presence of a Content-Length or
* Transfer-Encoding 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
* @throws HttpException if a protocol exception occurs.
* @throws HttpRecoverableException if a recoverable transport error occurs.
* Usually this kind of exceptions can be recovered from by
* retrying the HTTP method
*
* @see #readResponse
* @see #processResponseBody
*
* @since 2.0
*/
protected void readResponseBody(HttpState state, HttpConnection conn)
throws IOException {
LOG.trace(
"enter HeadMethod.readResponseBody(HttpState, HttpConnection)");
if (this.bodyCheckTimeout < 0) {
responseBodyConsumed();
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Check for non-compliant response body. Timeout in "
+ this.bodyCheckTimeout + " ms");
}
boolean responseAvailable = false;
try {
responseAvailable = conn.isResponseAvailable(this.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 (isStrictMode()) {
throw new HttpException(
"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);
}
}
}
/**
* Return non-compliant response body check timeout.
*
* @return 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
*/
public int getBodyCheckTimeout() {
return this.bodyCheckTimeout;
}
/**
* Set 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. -1 can be used to
* disable non-compliant response body check
*/
public void setBodyCheckTimeout(int timeout) {
this.bodyCheckTimeout = timeout;
}
}
