crafterm 2003/07/03 07:40:49
Modified: sourceresolve/src/java/org/apache/excalibur/source/impl
HTTPClientSourceFactory.java HTTPClientSource.java
Log:
Minor cleanups so that the connection with remote host is only
made when a request for the InputStream is made, rather than
during initialize().
Revision Changes Path
1.3 +2 -16
avalon-excalibur/sourceresolve/src/java/org/apache/excalibur/source/impl/HTTPClientSourceFactory.java
Index: HTTPClientSourceFactory.java
===================================================================
RCS file:
/home/cvs/avalon-excalibur/sourceresolve/src/java/org/apache/excalibur/source/impl/HTTPClientSourceFactory.java,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- HTTPClientSourceFactory.java 3 Jul 2003 09:46:32 -0000 1.2
+++ HTTPClientSourceFactory.java 3 Jul 2003 14:40:48 -0000 1.3
@@ -140,20 +140,6 @@
*/
public void release( final Source source )
{
- if ( source instanceof HTTPClientSource )
- {
- HTTPClientSource src = (HTTPClientSource) source;
-
- ContainerUtil.dispose( src );
- }
- else
- {
- if ( getLogger().isDebugEnabled() )
- {
- getLogger().debug(
- "Ignoring request to release non-HTTPClientSource object"
- );
- }
- }
+ // empty for the moment
}
}
1.3 +221 -92
avalon-excalibur/sourceresolve/src/java/org/apache/excalibur/source/impl/HTTPClientSource.java
Index: HTTPClientSource.java
===================================================================
RCS file:
/home/cvs/avalon-excalibur/sourceresolve/src/java/org/apache/excalibur/source/impl/HTTPClientSource.java,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- HTTPClientSource.java 3 Jul 2003 09:46:32 -0000 1.2
+++ HTTPClientSource.java 3 Jul 2003 14:40:48 -0000 1.3
@@ -56,13 +56,12 @@
import java.io.IOException;
import java.io.InputStream;
+import java.io.OutputStream;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
-import org.apache.avalon.framework.CascadingRuntimeException;
import org.apache.avalon.framework.activity.Initializable;
-import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameterizable;
@@ -75,11 +74,13 @@
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.URIException;
import org.apache.commons.httpclient.methods.GetMethod;
+import org.apache.commons.httpclient.methods.HeadMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceNotFoundException;
import org.apache.excalibur.source.SourceParameters;
import org.apache.excalibur.source.SourceResolver;
+import org.apache.excalibur.source.SourceUtil;
import org.apache.excalibur.source.SourceValidity;
import org.apache.excalibur.source.impl.validity.TimeStampValidity;
@@ -92,7 +93,7 @@
* @version CVS $Id$
*/
public class HTTPClientSource extends AbstractLogEnabled
- implements Source, Initializable, Parameterizable, Disposable
+ implements Source, Initializable, Parameterizable
{
/**
* Constant used for identifying POST requests.
@@ -145,11 +146,6 @@
private HttpClient m_client;
/**
- * The [EMAIL PROTECTED] HttpMethod} being performed on the [EMAIL PROTECTED]
HttpClient}.
- */
- private HttpMethod m_method;
-
- /**
* Proxy port if set via configuration.
*/
private int m_proxyPort;
@@ -160,10 +156,29 @@
private String m_proxyHost;
/**
- * HTTP response returned from server after the [EMAIL PROTECTED] HttpMethod}
- * has been performed.
+ * Whether the data held within this instance is currently accurate.
+ */
+ private boolean m_dataValid;
+
+ /**
+ * Whether the resource exists on the server.
+ */
+ private boolean m_exists;
+
+ /**
+ * The mime type of the resource on the server.
+ */
+ private String m_mimeType;
+
+ /**
+ * The content length of the resource on the server.
*/
- private int m_response;
+ private long m_contentLength;
+
+ /**
+ * The last modified date of the resource on the server.
+ */
+ private long m_lastModified;
/**
* Stored [EMAIL PROTECTED] SourceValidity} object.
@@ -227,8 +242,21 @@
m_client.getHostConfiguration().setProxy( m_proxyHost, m_proxyPort );
}
- m_method = getMethod();
- m_response = m_client.executeMethod( m_method );
+ m_dataValid = false;
+ }
+
+ /**
+ * Method to discover what kind of request is being made from the
+ * parameters map passed in to this Source's constructor.
+ *
+ * @return the method type, or if no method type can be found,
+ * HTTP GET is assumed.
+ */
+ private String findMethodType()
+ {
+ final String method =
+ (String) m_parameters.get( SourceResolver.METHOD );
+ return method == null ? GET : method;
}
/**
@@ -239,31 +267,34 @@
*/
private HttpMethod getMethod()
{
- final SourceParameters params =
- (SourceParameters) m_parameters.get( SourceResolver.URI_PARAMETERS );
- final String method =
- (String) m_parameters.get( SourceResolver.METHOD );
+ final String method = findMethodType();
// create a POST method if requested
if ( POST.equals( method ) )
{
- return createPostMethod( params );
+ return createPostMethod(
+ m_uri,
+ (SourceParameters) m_parameters.get( SourceResolver.URI_PARAMETERS )
+ );
}
// default method is GET
- return new GetMethod( m_uri );
+ return createGetMethod( m_uri );
}
/**
- * Helper method to create a new [EMAIL PROTECTED] PostMethod} with the given
+ * Factory method to create a new [EMAIL PROTECTED] PostMethod} with the given
* [EMAIL PROTECTED] SourceParameters} object.
*
+ * @param uri URI
* @param params [EMAIL PROTECTED] SourceParameters}
* @return a [EMAIL PROTECTED] PostMethod} instance
*/
- private PostMethod createPostMethod( final SourceParameters params )
+ private PostMethod createPostMethod(
+ final String uri, final SourceParameters params
+ )
{
- final PostMethod post = new PostMethod( m_uri );
+ final PostMethod post = new PostMethod( uri );
if ( params == null )
{
@@ -289,6 +320,108 @@
}
/**
+ * Factory method to create a [EMAIL PROTECTED] GetMethod} object.
+ *
+ * @param uri URI
+ * @return a [EMAIL PROTECTED] GetMethod} instance
+ */
+ private GetMethod createGetMethod( final String uri )
+ {
+ return new GetMethod( uri );
+ }
+
+ /**
+ * Factory method to create a [EMAIL PROTECTED] HeadMethod} object.
+ *
+ * @param uri URI
+ * @return a [EMAIL PROTECTED] HeadMethod} instance
+ */
+ private HeadMethod createHeadMethod( final String uri )
+ {
+ return new HeadMethod( uri );
+ }
+
+ /**
+ * Method to make response data available if possible without
+ * actually making an actual request (ie. via HTTP HEAD).
+ */
+ private void updateData()
+ {
+ // no request made so far, attempt to get some response data.
+ if ( !m_dataValid )
+ {
+ if ( GET.equals( findMethodType() ) )
+ {
+ try
+ {
+ final HttpMethod head = createHeadMethod( m_uri );
+ executeMethod( head );
+ head.releaseConnection();
+ return;
+ }
+ catch ( final IOException e )
+ {
+ if ( getLogger().isDebugEnabled() )
+ {
+ getLogger().debug(
+ "Unable to determine response data, using defaults", e
+ );
+ }
+ }
+ }
+
+ // default values when response data is not available
+ m_exists = false;
+ m_mimeType = null;
+ m_contentLength = -1;
+ m_lastModified = 0;
+ m_dataValid = true;
+ }
+ }
+
+ /**
+ * Executes a particular [EMAIL PROTECTED] HttpMethod} and updates internal
+ * data storage.
+ *
+ * @param method [EMAIL PROTECTED] HttpMethod} to execute
+ * @return response code from server
+ * @exception IOException if an error occurs
+ */
+ private int executeMethod( final HttpMethod method )
+ throws IOException
+ {
+ final int response = m_client.executeMethod( method );
+
+ updateExists( method );
+ updateMimeType( method );
+ updateContentLength( method );
+ updateLastModified( method );
+
+ // all finished, return response code to the caller.
+ return response;
+ }
+
+ /**
+ * Method to update whether a referenced resource exists, after
+ * executing a particular [EMAIL PROTECTED] HttpMethod}.
+ *
+ * @param method [EMAIL PROTECTED] HttpMethod} executed.
+ */
+ private void updateExists( final HttpMethod method )
+ {
+ final int response = method.getStatusCode();
+
+ // REVISIT(MC): should this return true if the server does
+ // not return a 404, or a 410, or should it only return true
+ // if the user can successfully get an InputStream from
+ // it without getting errors.
+
+ // resource does not exist if HttpClient returns a 404 or a 410
+ m_exists = !( response == HttpStatus.SC_GONE ||
+ response == HttpStatus.SC_NOT_FOUND );
+ }
+
+ /**
* Method to ascertain whether the given resource actually exists.
*
* @return <code>true</code> if the resource pointed to by the
@@ -297,15 +430,10 @@
*/
public boolean exists()
{
- // REVISIT(MC): should this return true if the server does not return
- // a 404, or a 410, or should it only return true if the user can
- // successfully get an InputStream from it without getting errors.
-
- // resource does not exist if HttpClient returns a 404 or a 410
- return !( m_response == HttpStatus.SC_GONE ||
- m_response == HttpStatus.SC_NOT_FOUND );
+ updateData();
+ return m_exists;
}
-
+
/**
* Method to obtain an [EMAIL PROTECTED] InputStream} to read the response
* from the server.
@@ -317,21 +445,25 @@
public InputStream getInputStream()
throws IOException, SourceNotFoundException
{
+ final HttpMethod method = getMethod();
+ final int response = executeMethod( method );
+ m_dataValid = true;
+
// throw SourceNotFoundException - according to Source API we
// need to throw this if the source doesn't exist.
if ( !exists() )
{
final StringBuffer error = new StringBuffer();
error.append( "Unable to retrieve URI: " );
- error.append( m_method.getURI() );
+ error.append( m_uri );
error.append( " (" );
- error.append( m_response );
+ error.append( response );
error.append( ")" );
throw new SourceNotFoundException( error.toString() );
}
- return m_method.getResponseBodyAsStream();
+ return method.getResponseBodyAsStream();
}
/**
@@ -341,14 +473,7 @@
*/
public String getURI()
{
- try
- {
- return m_method.getURI().getURI();
- }
- catch ( final URIException e )
- {
- throw new CascadingRuntimeException( "Unable to determine URI", e );
- }
+ return m_uri;
}
/**
@@ -359,14 +484,7 @@
*/
public String getScheme()
{
- try
- {
- return m_method.getURI().getScheme();
- }
- catch ( final URIException e )
- {
- throw new CascadingRuntimeException( "Unable to determine URI Scheme",
e );
- }
+ return SourceUtil.getScheme( m_uri );
}
/**
@@ -392,6 +510,7 @@
m_cachedValidity = new TimeStampValidity( lm );
return m_cachedValidity;
}
+
return null;
}
@@ -400,23 +519,20 @@
*/
public void refresh()
{
- try
- {
- recycle();
- initialize();
- }
- catch ( final Exception e )
- {
- final StringBuffer buf = new StringBuffer();
- buf.append( "Refresh on " );
- buf.append( m_uri );
- buf.append( " failed" );
+ recycle();
+ }
- if ( getLogger().isWarnEnabled() )
- {
- getLogger().warn( buf.toString(), e );
- }
- }
+ /**
+ * Method to update the mime type of a resource after
+ * executing a particular [EMAIL PROTECTED] HttpMethod}.
+ *
+ * @param method [EMAIL PROTECTED] HttpMethod} executed
+ */
+ private void updateMimeType( final HttpMethod method )
+ {
+ // REVISIT: should this be the mime-type, or the content-type -> URLSource
+ // returns the Content-Type, so we'll follow that for now.
+ m_mimeType = method.getResponseHeader( CONTENT_TYPE ).getValue();
}
/**
@@ -426,24 +542,24 @@
*/
public String getMimeType()
{
- // REVISIT: should this be the mime-type, or the content-type -> URLSource
- // returns the Content-Type, so we'll follow that for now.
- return m_method.getResponseHeader( CONTENT_TYPE ).getValue();
+ updateData();
+ return m_mimeType;
}
/**
- * Obtain the content length of the referenced resource.
- *
- * @return content length of the referenced resource, or
- * -1 if unknown/uncalculatable
+ * Method to update the content length of a resource after
+ * executing a particular [EMAIL PROTECTED] HttpMethod}.
+ *
+ * @param method [EMAIL PROTECTED] HttpMethod} executed
*/
- public long getContentLength()
+ private void updateContentLength( final HttpMethod method )
{
try
{
final Header length =
- m_method.getResponseHeader( CONTENT_LENGTH );
- return length == null ? -1 : Long.parseLong( length.getValue() );
+ method.getResponseHeader( CONTENT_LENGTH );
+ m_contentLength =
+ length == null ? -1 : Long.parseLong( length.getValue() );
}
catch ( final NumberFormatException e )
{
@@ -454,40 +570,53 @@
);
}
- return -1;
+ m_contentLength = -1;
}
}
/**
- * Get the last modification date of this source. This date is
- * measured in milliseconds since the Epoch (00:00:00 GMT, January 1, 1970).
+ * Obtain the content length of the referenced resource.
*
- * @return the last modification date or <code>0</code> if unknown.
+ * @return content length of the referenced resource, or
+ * -1 if unknown/uncalculatable
*/
- public long getLastModified()
+ public long getContentLength()
{
- final Header lastModified = m_method.getResponseHeader( LAST_MODIFIED );
- return lastModified == null ? 0 : Date.parse( lastModified.getValue() );
+ updateData();
+ return m_contentLength;
}
/**
- * Disposes this [EMAIL PROTECTED] HTTPClientSource} instance.
+ * Method to update the last modified date of a resource after
+ * executing a particular [EMAIL PROTECTED] HttpMethod}.
+ *
+ * @param method [EMAIL PROTECTED] HttpMethod} executed
*/
- public void dispose()
+ private void updateLastModified( final HttpMethod method )
{
- if ( m_method != null )
- {
- m_method.releaseConnection();
- }
+ final Header lastModified = method.getResponseHeader( LAST_MODIFIED );
+ m_lastModified =
+ lastModified == null ? 0 : Date.parse( lastModified.getValue() );
+ }
+
+ /**
+ * Get the last modification date of this source. This date is
+ * measured in milliseconds since the Epoch (00:00:00 GMT, January 1, 1970).
+ *
+ * @return the last modification date or <code>0</code> if unknown.
+ */
+ public long getLastModified()
+ {
+ updateData();
+ return m_lastModified;
}
/**
* Recycles this [EMAIL PROTECTED] HTTPClientSource} object so that it may be
reused
- * to refresh it's content. Note, after this method is called,
- * [EMAIL PROTECTED] HTTPClientSource}.invoke should be invoked.
+ * to refresh it's content.
*/
private void recycle()
{
- m_method.recycle();
+ m_dataValid = false;
}
}
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