/*
* Copyright 2011 <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
* 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.ocpsoft.rewrite.servlet.config;
import java.net.MalformedURLException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import org.ocpsoft.common.pattern.WeightedComparator;
import org.ocpsoft.common.services.ServiceLoader;
import org.ocpsoft.common.util.Iterators;
import org.ocpsoft.logging.Logger;
import org.ocpsoft.rewrite.config.Condition;
import org.ocpsoft.rewrite.config.ConfigurationRuleParameterBuilder;
import org.ocpsoft.rewrite.context.EvaluationContext;
import org.ocpsoft.rewrite.param.ParameterStore;
import org.ocpsoft.rewrite.param.Parameterized;
import org.ocpsoft.rewrite.param.ParameterizedPattern;
import org.ocpsoft.rewrite.param.ParameterizedPatternBuilder;
import org.ocpsoft.rewrite.param.RegexParameterizedPatternBuilder;
import org.ocpsoft.rewrite.servlet.ServletRegistration;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
import org.ocpsoft.rewrite.servlet.spi.ServletRegistrationProvider;
import org.ocpsoft.rewrite.util.Transpositions;
import org.ocpsoft.urlbuilder.Address;
/**
* A {@link Condition} responsible for comparing the current {@link Address} to Servlet Mappings defined in the current
* {@link ServletContext}.
*
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*/
public abstract class ServletMapping extends HttpCondition implements Parameterized
{
private static final Logger log = Logger.getLogger(Resource.class);
private final RegexParameterizedPatternBuilder resource;
private List<ServletRegistrationProvider> servletRegistrationProviders = null;
private ServletMapping(final String resource)
{
this.resource = new RegexParameterizedPatternBuilder(resource);
}
/**
* Create a {@link Condition} that returns <code>true</code> if the given resource is mapped by any {@link Servlet}
* instances registered within the current application, and returns <code>false</code> if no {@link Servlet} will
* handle the specified resource pattern.
*
* <p>
* The given resource path may be parameterized:
* <p>
* <code>
* /example/{param}.html <br>
* /css/{value}.css <br>
* ...
* </code>
* <p>
*
* @param location {@link ParameterizedPattern} specifying the {@link Address} of the internal resource.
*
* @see {@link ConfigurationRuleParameterBuilder#where(String)}
*/
public static ServletMapping includes(final String resource)
{
return new ServletMapping(resource) {
@Override
public String toString()
{
return "ServletMapping.includes(\"" + resource + "\")";
}
};
}
@Override
public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
{
if (resource != null && resource.isParameterComplete(event, context))
{
String path = resource.build(event, context, Transpositions.encodePath());
try
{
for (ServletRegistration registration : getServletRegistration(event.getServletContext()))
{
Collection<String> mappings = registration.getMappings();
for (String mapping : mappings)
{
if (path.startsWith("/") && !mapping.startsWith("/"))
{
mapping = "/" + mapping;
}
if (mapping.contains("*"))
{
mapping = mapping.replaceAll("\\*", ".*");
}
if (path.matches(mapping))
{
return true;
}
}
}
return event.getServletContext().getResource(path) != null;
}
catch (MalformedURLException e)
{
log.debug("Invalid file format [{}]", path);
}
}
return false;
}
/**
* Obtains the list of registered {@link Servlet} instances using the {@link ServletRegistrationProvider} SPI.
*/
private List<ServletRegistration> getServletRegistration(ServletContext context)
{
for (ServletRegistrationProvider provider : getServletRegistrationProviders())
{
List<ServletRegistration> registrations = provider.getServletRegistrations(context);
if (registrations != null)
{
return registrations;
}
}
throw new IllegalStateException("Unable to find the Servlet registrations of the application");
}
/**
* Returns the list of {@link ServletRegistrationProvider} implementations.
*/
private List<ServletRegistrationProvider> getServletRegistrationProviders()
{
if (servletRegistrationProviders == null)
{
servletRegistrationProviders = Iterators.asList(
ServiceLoader.loadTypesafe(ServletRegistrationProvider.class).iterator());
Collections.sort(servletRegistrationProviders, new WeightedComparator());
}
return servletRegistrationProviders;
}
/**
* Return the underlying {@link ParameterizedPatternBuilder} for this {@link ServletMapping}.
*/
public ParameterizedPatternBuilder getResourceExpression()
{
return resource;
}
@Override
public Set<String> getRequiredParameterNames()
{
return resource.getRequiredParameterNames();
}
@Override
public void setParameterStore(ParameterStore store)
{
resource.setParameterStore(store);
}
}