/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.
*/
package org.apache.cocoon.matching;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.DefaultConfigurationBuilder;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameterizable;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.components.source.SourceUtil;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.sitemap.PatternException;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import org.apache.excalibur.source.SourceValidity;
/**
* A matcher that manages a "mount table", allowing to add subsitemaps to a Cocoon application without
* modifying the main sitemap. This is especially useful for prototypes and demos where installing
* a separate instance of Cocoon is overkill.
* <p>
* The mount table is an xml file which has a format similar to the <code>map:mount</code> syntax:
* <pre>
* <mount-table>
* <mount uri-prefix="foo" src="file://path/to/foo/directory/"/>
* <mount uri-prefix="bar/baz" src="file://path/to/bar-baz/directory/"/>
* </mount-table>
* </pre>
* The matcher will scan the mount table for an "uri-prefix" value matching the beginning of the current
* request URI, and if found, succeed and populate the "src" and "uri-prefix" sitemap variables.
* <p>
* Usage in the sitemap is therefore as follows:
* <pre>
* <map:match type="mount-table" pattern="path/to/mount-table.xml">
* <map:mount uri-prefix="{uri-prefix}" src="{src}"/>
* </map:match>
* </pre>
* <p>
* This matcher accepts a single configuration parameter, indicating if missing mount tables should be
* silently ignored (defaults is <code>false</code>, meaning "don't ignore"):
* <pre>
* <map:matcher type="mount-table" src="org.apache.cocoon.matching.MountTableMatcher">
* <map:parameter name="ignore-missing-tables" value="true"/>
* </map:matcher>
* </pre>
* <p>
* This configuration is used in the main sitemap of Cocoon samples, to allow users to define their own mount
* table, but not fail if it does not exist.
*
* @author <a href="http://www.apache.org/~sylvain/">Sylvain Wallez</a>
* @version CVS $Id: MountTableMatcher.java,v 1.7 2004/03/05 13:02:56 bdelacretaz Exp $
*/
public class MountTableMatcher extends AbstractLogEnabled implements Matcher, ThreadSafe, Serviceable, Parameterizable {
private ServiceManager manager;
private SourceResolver resolver;
private Map mountTables = Collections.synchronizedMap(new HashMap());
private boolean ignoreMissingTables = false;
public void service(ServiceManager manager) throws ServiceException {
this.manager = manager;
this.resolver = (SourceResolver)this.manager.lookup(SourceResolver.ROLE);
}
public void parameterize(Parameters params) throws ParameterException {
this.ignoreMissingTables = params.getParameterAsBoolean("ignore-missing-tables", false);
}
private Map getMountTable(String src) throws Exception {
Source source = resolver.resolveURI(src);
String uri = source.getURI();
// Check if source exists
if (!source.exists()) {
resolver.release(source);
if (this.ignoreMissingTables) {
return Collections.EMPTY_MAP;
} else {
throw new PatternException("Mount table does not exist: '" + uri + "'");
}
}
// Source exists
Object[] values = (Object[])this.mountTables.get(uri);
if (values != null) {
// Check validity
SourceValidity oldValidity = (SourceValidity)values[1];
int valid = oldValidity.isValid();
if (valid == 1) {
// Valid without needing the new validity
return (Map)values[0];
}
if (valid == 0 && oldValidity.isValid(source.getValidity()) == 1) {
// Valid after comparing with the new validity
return (Map)values[0];
}
// Invalid: fallback below to read the mount table
} else {
values = new Object[2];
}
// Read the mount table
Map mounts = new HashMap();
DefaultConfigurationBuilder builder = new DefaultConfigurationBuilder();
Configuration config = builder.build(SourceUtil.getInputSource(source));
this.resolver.release(source);
Configuration[] children = config.getChildren();
for (int i = 0; i < children.length; i++) {
Configuration child = children[i];
if ("mount".equals(child.getName())) {
String prefix = children[i].getAttribute("uri-prefix");
// Append a '/' at the end of the prefix
// this avoids flat uri matching which would cause
// exceptions in the sub sitemap!
if (!prefix.endsWith("/")) {
prefix = prefix + '/';
}
mounts.put(prefix, children[i].getAttribute("src"));
} else {
throw new PatternException(
"Unexpected element '" + child.getName() + "' (awaiting 'mount'), at " + child.getLocation());
}
}
values[0] = mounts;
values[1] = source.getValidity();
// Cache it with the source validity
this.mountTables.put(uri, values);
return mounts;
}
public Map match(String pattern, Map objectModel, Parameters parameters) throws PatternException {
Map mounts;
try {
mounts = getMountTable(pattern);
} catch(PatternException pe) {
throw pe;
} catch(Exception e) {
throw new PatternException(e);
}
// Get the request URI
Request request = ObjectModelHelper.getRequest(objectModel);
String uri = request.getSitemapURI();
// and search for a matching prefix
Iterator iter = mounts.entrySet().iterator();
while(iter.hasNext()) {
Map.Entry entry = (Map.Entry)iter.next();
String prefix = (String)entry.getKey();
if (uri.startsWith(prefix)) {
// Found it
Map result = new HashMap(2);
result.put("uri-prefix", prefix);
result.put("src", entry.getValue());
// Return immediately
return result;
}
}
// Not found
return null;
}
}