haul 2003/08/15 08:55:45
Added: src/java/org/apache/cocoon/components/modules/input
LocateResource.java
Log:
new module to locate files in a hierarchie
Revision Changes Path
1.1
cocoon-2.1/src/java/org/apache/cocoon/components/modules/input/LocateResource.java
Index: LocateResource.java
===================================================================
/*
============================================================================
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 modifica-
tion, 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.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Apache Cocoon" and "Apache Software Foundation" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
[EMAIL PROTECTED]
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
on behalf of the Apache Software Foundation and was originally created by
Stefano Mazzocchi <[EMAIL PROTECTED]>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.components.modules.input;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeSet;
import java.util.Vector;
/**
* Loacte a resource in a resource tree. Any attribute name is interpreted as
a
* URI with the last part being the resource name unless it ends with a
slash.
* The URI is checked if the resource exists and the URI is returned. If the
* resource does not exist, the URI is shortened until the resource name is
found
* and the new URI is returned. If no resource with the given name exists,
null
* is returned.
*
* <p>A use case is to locate the closest menu file or when moving a site from
* a filesystem path == URL system from a httpd to Cocoon and provide similar
* functions to .htaccess files.</p>
*
* <p>Example: for context:/some/path/to/a/file.xml the following URIs
* are tested: context:/some/path/to/a/file.xml,
context:/some/path/to/file.xml,
* context:/some/path/file.xml, context:/some/file.xml, and context:/file.xml.
* For the attribute name context:/some/path/foo/ tests
context:/some/path/foo/,
* context:/some/path/, context:/some/, and context:/ are tested.</p>
*
* <p>The getAttribute() method will return the URI for the first match while
* getAttributeValues() will return an array of all existing paths.
* getAttributeNames() will return an Iterator to an empty collection.</p>
*
* @author <a href="mailto:[EMAIL PROTECTED]">Christian Haul</a>
* @version CVS $Id: LocateResource.java,v 1.1 2003/08/15 15:55:45 haul Exp $
*/
public class LocateResource extends AbstractInputModule implements
Composable, ThreadSafe {
protected static Collection col = null;
static {
col = new TreeSet();
}
protected ComponentManager manager = null;
/**
* Calculate the minimal length of the URL, that is the position
* of the first ":" if a protocol is provided or otherwise 0.
* @param name
* @return
*/
protected int calculateMinLen(String name) {
int minLen = name.indexOf(':');
minLen = (minLen == -1 ? 0 : minLen);
return minLen;
}
/**
* Remove one path element from the URL unless minimum length has
* been reached.
*
* @param urlstring
* @param minLen
* @return
*/
protected String shortenURI(String urlstring, int minLen) {
int idx = urlstring.lastIndexOf('/');
idx = (idx <= minLen + 1) ? minLen : idx;
urlstring = urlstring.substring(0, idx);
return urlstring;
}
/**
* if the url does not end with a "/", keep the last part in
* order to add it later again after traversing up
*/
protected String extractFilename(String urlstring) {
String filename = "";
if (!urlstring.endsWith("/")) {
int idx = urlstring.lastIndexOf('/');
filename = urlstring.substring(idx);
}
return filename;
}
/**
* Locate a resource with the given URL consisting of urlstring +
filename.
* The filename is appended each time the path is shortened. Returns the
first
* existing occurance.
*
* @param urlstring
* @param filename
* @param minLen
* @return
*/
protected String locateResource(String urlstring, String filename, int
minLen) {
String sourcename = null;
Source src = null;
SourceResolver resolver = null;
boolean found = false;
try {
resolver =
(SourceResolver) this.manager.lookup(
org.apache.excalibur.source.SourceResolver.ROLE);
while (!found && urlstring.length() > minLen) {
sourcename = urlstring + filename;
try {
src = resolver.resolveURI(sourcename);
if (src.exists())
found = true;
} catch (Exception e) {
if (this.getLogger().isWarnEnabled())
this.getLogger().warn("Exception resolving URL " +
sourcename, e);
} finally {
resolver.release(src);
}
if (!found) {
urlstring = shortenURI(urlstring, minLen);
}
}
} catch (ComponentException e1) {
if (this.getLogger().isErrorEnabled())
this.getLogger().error("Exception obtaining source resolver
", e1);
} finally {
if (resolver != null) {
this.manager.release(resolver);
}
}
return (found ? urlstring : null);
}
/**
* Set the current <code>ComponentManager</code> instance used by this
* <code>Composable</code>.
*/
public void compose(ComponentManager manager) throws ComponentException {
this.manager = manager;
}
/* (non-Javadoc)
* @see
org.apache.cocoon.components.modules.input.InputModule#getAttribute(java.lang.String,
org.apache.avalon.framework.configuration.Configuration, java.util.Map)
*/
public Object getAttribute(String name, Configuration modeConf, Map
objectModel)
throws ConfigurationException {
String urlstring = name;
String filename = extractFilename(urlstring);
int minLen = calculateMinLen(name);
if (filename != "") {
urlstring = shortenURI(urlstring, minLen);
}
String result = locateResource(urlstring, filename, minLen);
result = (result == null? result : result + filename);
if (this.getLogger().isDebugEnabled())
this.getLogger().debug(
"located " + name + " @ " + result);
return result;
}
/* (non-Javadoc)
* @see
org.apache.cocoon.components.modules.input.InputModule#getAttributeNames(org.apache.avalon.framework.configuration.Configuration,
java.util.Map)
*/
public Iterator getAttributeNames(Configuration modeConf, Map objectModel)
throws ConfigurationException {
// return an iterator to an empty collection
return LocateResource.col.iterator();
}
/* (non-Javadoc)
* @see
org.apache.cocoon.components.modules.input.InputModule#getAttributeValues(java.lang.String,
org.apache.avalon.framework.configuration.Configuration, java.util.Map)
*/
public Object[] getAttributeValues(String name, Configuration modeConf,
Map objectModel)
throws ConfigurationException {
Vector uris = null;
String urlstring = name;
String filename = extractFilename(urlstring);
int minLen = calculateMinLen(name);
if (filename != "") {
urlstring = shortenURI(urlstring, minLen);
}
while (urlstring != null && urlstring.length() > minLen) {
urlstring = this.locateResource(urlstring, filename, minLen);
if (urlstring != null) {
if (uris == null)
uris = new Vector();
if (this.getLogger().isDebugEnabled())
this.getLogger().debug("-> located " + name + " @ " +
urlstring + filename);
uris.add(urlstring + filename);
urlstring = shortenURI(urlstring, minLen);
}
}
return (uris == null ? null : uris.toArray());
}
}
