/*
* 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.Set;
import javax.servlet.ServletContext;
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.ParameterizedPatternParser;
import org.ocpsoft.rewrite.param.RegexParameterizedPatternParser;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
import org.ocpsoft.rewrite.util.Transpositions;
import org.ocpsoft.urlbuilder.Address;
/**
* A {@link Condition} responsible for determining existence of resources within the
* {@link ServletContext#getResourcePaths(String)} of the servlet container.
*
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*/
public abstract class Resource extends HttpCondition implements Parameterized
{
private static final Logger log = Logger.getLogger(Resource.class);
private final ParameterizedPatternParser resource;
private Resource(final String resource)
{
this.resource = new RegexParameterizedPatternParser(resource);
}
@Override
public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
{
if (resource != null)
{
ParameterizedPatternBuilder builder = resource.getBuilder();
if (builder.isParameterComplete(event, context))
{
String file = builder.build(event, context, Transpositions.encodePath());
try
{
return (event.getServletContext().getResource(file) != null);
}
catch (MalformedURLException e)
{
log.debug("Invalid file format [{}]", file);
}
}
else
{
/*
* Parameter didn't exist, that's OK, switch to parsing mode.
*/
@SuppressWarnings("unchecked")
Set<String> paths = event.getServletContext().getResourcePaths("/");
for (String path : paths)
{
if (resource.parse(path).matches())
{
return true;
}
}
}
}
return false;
}
/**
* Create a {@link Condition} that returns <code>true</code> if the given resource exists in the
* {@link ServletContext#getResourcePaths(String)} of the current application.
*
* <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 Resource exists(final String resource)
{
return new Resource(resource) {
@Override
public String toString()
{
return "Resource.exists(\"" + resource + "\")";
}
};
}
/**
* Get the {@link ParameterizedPattern} of this {@link Resource}.
*/
public ParameterizedPatternParser getExpression()
{
return resource;
}
@Override
public Set<String> getRequiredParameterNames()
{
return resource.getRequiredParameterNames();
}
@Override
public void setParameterStore(ParameterStore store)
{
resource.setParameterStore(store);
}
}