/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 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;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* 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 $Id$
*/
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;
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 = null;
try {
source = this.resolver.resolveURI(src);
final String uri = source.getURI();
// Check if source exists
if (!source.exists()) {
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 != null ? oldValidity.isValid() : SourceValidity.INVALID;
if (valid == SourceValidity.VALID) {
// Valid without needing the new validity
return (Map) values[0];
}
if (valid == SourceValidity.UNKNOWN &&
oldValidity.isValid(source.getValidity()) == SourceValidity.VALID) {
// 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));
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 a not-empty prefix
// this avoids flat uri matching which would cause
// exceptions in the sub sitemap!
if (!prefix.endsWith("/") && prefix.length() != 0) {
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;
} catch (SecurityException e) {
if (this.ignoreMissingTables) {
return Collections.EMPTY_MAP;
} else {
throw new PatternException("Mount table is not accessible: '" + src + "' (" + e + ")");
}
} finally {
if (source != null) {
this.resolver.release(source);
}
}
}
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;
}
}