org.apache.excalibur.source.impl
Class HTTPClientSource

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.excalibur.source.impl.HTTPClientSource

All Implemented Interfaces:

org.apache.avalon.framework.activity.Initializable, LogEnabled, org.apache.avalon.framework.parameters.Parameterizable, ModifiableSource, Source

public class HTTPClientSource
extends AbstractLogEnabled
implements ModifiableSource, org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.parameters.Parameterizable

HTTP URL Source object, based on the Jakarta Commons HttpClient project.

Version:

CVS $Id: HTTPClientSource.java,v 1.4 2004/02/28 11:47:24 cziegeler Exp $

Author:

Avalon Development Team

Field Summary

static String	CONTENT_LENGTH Constant used when obtaining the Content-Length from HTTP Headers
static String	CONTENT_TYPE Constant used when obtaining the Content-Type from HTTP Headers
static String	GET Constant used for identifying GET requests.
static String	LAST_MODIFIED Constant used when obtaining the Last-Modified date from HTTP Headers
static String	POST Constant used for identifying POST requests.
static String	PROXY_HOST Constant used for configuring the proxy hostname.
static String	PROXY_PORT Constant used for configuring the proxy port number.

Constructor Summary

HTTPClientSource(String uri, Map parameters, org.apache.commons.httpclient.HttpState httpState)
Constructor, creates a new HTTPClientSource instance.

Method Summary

boolean	canCancel(OutputStream stream) Method to determine whether writing to the supplied OutputStream (which must be that returned from getOutputStream()) can be cancelled
void	cancel(OutputStream stream) Cancels any data sent to the OutputStream returned by getOutputStream().
void	delete() Deletes the referenced resource.
protected int	executeMethod(org.apache.commons.httpclient.HttpMethod method) Executes a particular HttpMethod and updates internal data storage.
boolean	exists() Method to ascertain whether the given resource actually exists.
long	getContentLength() Obtain the content length of the referenced resource.
InputStream	getInputStream() Method to obtain an InputStream to read the response from the server.
long	getLastModified() Get the last modification date of this source.
String	getMimeType() Obtain the mime-type for the referenced resource.
OutputStream	getOutputStream() Obtain an OutputStream to write to.
String	getScheme() Return the URI scheme identifier, ie.
String	getURI() Obtain the absolute URI this Source object references.
SourceValidity	getValidity() Obtain a SourceValidity object.
void	initialize() Initializes this HTTPClientSource instance.
void	parameterize(org.apache.avalon.framework.parameters.Parameters params) Parameterizes this HTTPClientSource instance.
void	refresh() Refreshes this Source object.

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

POST

public static final String POST

Constant used for identifying POST requests.

See Also:

Constant Field Values

GET

public static final String GET

Constant used for identifying GET requests.

See Also:

Constant Field Values

PROXY_HOST

public static final String PROXY_HOST

Constant used for configuring the proxy hostname.

See Also:

Constant Field Values

PROXY_PORT

public static final String PROXY_PORT

Constant used for configuring the proxy port number.

See Also:

Constant Field Values

CONTENT_TYPE

public static final String CONTENT_TYPE

Constant used when obtaining the Content-Type from HTTP Headers

See Also:

Constant Field Values

CONTENT_LENGTH

public static final String CONTENT_LENGTH

Constant used when obtaining the Content-Length from HTTP Headers

See Also:

Constant Field Values

LAST_MODIFIED

public static final String LAST_MODIFIED

Constant used when obtaining the Last-Modified date from HTTP Headers

See Also:

Constant Field Values

Constructor Detail

HTTPClientSource

public HTTPClientSource(String uri,
                        Map parameters,
                        org.apache.commons.httpclient.HttpState httpState)
                 throws Exception

Constructor, creates a new HTTPClientSource instance.

Parameters:

uri - URI

parameters - contextual parameters passed to this instance

Throws:

Exception - if an error occurs

Method Detail

parameterize

public void parameterize(org.apache.avalon.framework.parameters.Parameters params)
                  throws org.apache.avalon.framework.parameters.ParameterException

Parameterizes this HTTPClientSource instance.

Specified by:

parameterize in interface org.apache.avalon.framework.parameters.Parameterizable

Parameters:

params - a Parameters instance.

Throws:

org.apache.avalon.framework.parameters.ParameterException - if an error occurs

initialize

public void initialize()
                throws Exception

Initializes this HTTPClientSource instance.

Specified by:

initialize in interface org.apache.avalon.framework.activity.Initializable

Throws:

Exception - if an error occurs

executeMethod

protected int executeMethod(org.apache.commons.httpclient.HttpMethod method)
                     throws IOException

Executes a particular HttpMethod and updates internal data storage.

Parameters:

method - HttpMethod to execute

Returns:

response code from server

Throws:

IOException - if an error occurs

exists

public boolean exists()

Method to ascertain whether the given resource actually exists.

Specified by:

exists in interface Source

Returns:

true if the resource pointed to by the URI during construction exists, false otherwise.

getInputStream

public InputStream getInputStream()
                           throws IOException,
                                  SourceNotFoundException

Method to obtain an InputStream to read the response from the server.

Specified by:

getInputStream in interface Source

Returns:

InputStream containing data sent from the server.

Throws:

IOException - if some I/O problem occurs.

SourceNotFoundException - if the source doesn't exist.

getURI

public String getURI()

Obtain the absolute URI this Source object references.

Specified by:

getURI in interface Source

Returns:

the absolute URI this String object references.

getScheme

public String getScheme()

Return the URI scheme identifier, ie. the part preceding the fist ':' in the URI (see RFC 2396).

Specified by:

getScheme in interface Source

Returns:

the URI scheme identifier

getValidity

public SourceValidity getValidity()

Obtain a SourceValidity object.

Specified by:

getValidity in interface Source

Returns:

a SourceValidity object, or null if this is not possible.

refresh

public void refresh()

Refreshes this Source object.

Specified by:

refresh in interface Source

getMimeType

public String getMimeType()

Obtain the mime-type for the referenced resource.

Specified by:

getMimeType in interface Source

Returns:

mime-type for the referenced resource.

getContentLength

public long getContentLength()

Obtain the content length of the referenced resource.

Specified by:

getContentLength in interface Source

Returns:

content length of the referenced resource, or -1 if unknown/uncalculatable

getLastModified

public long getLastModified()

Get the last modification date of this source. This date is measured in milliseconds since the Epoch (00:00:00 GMT, January 1, 1970).

Specified by:

getLastModified in interface Source

Returns:

the last modification date or 0 if unknown.

getOutputStream

public OutputStream getOutputStream()
                             throws IOException

Obtain an OutputStream to write to. The OutputStream returned actually references a temporary local file, which will be written to the server upon closing. The returned stream must be closed or cancelled by the calling code.

Specified by:

getOutputStream in interface ModifiableSource

Returns:

an OutputStream instance

Throws:

IOException - if an error occurs

delete

public void delete()
            throws SourceException

Deletes the referenced resource.

Specified by:

delete in interface ModifiableSource

Throws:

SourceException - if an error occurs

canCancel

public boolean canCancel(OutputStream stream)

Method to determine whether writing to the supplied OutputStream (which must be that returned from getOutputStream()) can be cancelled

Specified by:

canCancel in interface ModifiableSource

Returns:

true if writing to the stream can be cancelled, false otherwise

cancel

public void cancel(OutputStream stream)
            throws IOException

Cancels any data sent to the OutputStream returned by getOutputStream(). After calling this method, the supplied OutputStream should no longer be used.

Specified by:

cancel in interface ModifiableSource

Throws:

IOException