/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. 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. For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.roller.weblogger.ui.rendering.filters;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.roller.weblogger.config.WebloggerConfig;
import org.apache.roller.weblogger.ui.rendering.RequestMapper;
/**
* Provides generalized request mapping capablilites.
*
* Incoming requests can be inspected by a series of RequestMappers and can
* potentially be re-routed to different places within the application.
*
* @web.filter name="RequestMappingFilter"
*/
public class RequestMappingFilter implements Filter {
private static Log log = LogFactory.getLog(RequestMappingFilter.class);
// list of RequestMappers that want to inspect the request
private final List requestMappers = new ArrayList();
public void init(FilterConfig filterConfig) {
// lookup set of request mappers we are going to use
String rollerMappers = WebloggerConfig.getProperty("rendering.rollerRequestMappers");
String userMappers = WebloggerConfig.getProperty("rendering.userRequestMappers");
// instantiate user defined request mapper classes
if(userMappers != null && userMappers.trim().length() > 0) {
RequestMapper requestMapper = null;
String[] uMappers = userMappers.split(",");
for(int i=0; i < uMappers.length; i++) {
try {
Class mapperClass = Class.forName(uMappers[i]);
requestMapper = (RequestMapper) mapperClass.newInstance();
requestMappers.add(requestMapper);
} catch(ClassCastException cce) {
log.error("It appears that your mapper does not implement "+
"the RequestMapper interface", cce);
} catch(Exception e) {
log.error("Unable to instantiate request mapper ["+uMappers[i]+"]", e);
}
}
}
// instantiate roller standard request mapper classes
if(rollerMappers != null && rollerMappers.trim().length() > 0) {
RequestMapper requestMapper = null;
String[] rMappers = rollerMappers.split(",");
for(int i=0; i < rMappers.length; i++) {
try {
Class mapperClass = Class.forName(rMappers[i]);
requestMapper = (RequestMapper) mapperClass.newInstance();
requestMappers.add(requestMapper);
} catch(ClassCastException cce) {
log.error("It appears that your mapper does not implement "+
"the RequestMapper interface", cce);
} catch(Exception e) {
log.error("Unable to instantiate request mapper ["+rMappers[i]+"]", e);
}
}
}
if(requestMappers.size() < 1) {
// hmm ... failed to load any request mappers?
log.warn("Failed to load any request mappers. "+
"Weblog urls probably won't function as you expect.");
}
log.info("Request mapping filter initialized, "+requestMappers.size()+
" mappers configured.");
}
/**
* Inspect incoming urls and see if they should be routed.
*/
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
log.debug("entering");
// give each mapper a chance to handle the request
RequestMapper mapper = null;
Iterator mappersIT = this.requestMappers.iterator();
while(mappersIT.hasNext()) {
mapper = (RequestMapper) mappersIT.next();
log.debug("trying mapper "+mapper.getClass().getName());
boolean wasHandled = mapper.handleRequest(request, response);
if(wasHandled) {
// if mapper has handled the request then we are done
log.debug("request handled by "+mapper.getClass().getName());
log.debug("exiting");
return;
}
}
log.debug("request not mapped");
// nobody handled the request, so let it continue as usual
chain.doFilter(request, response);
log.debug("exiting");
}
public void destroy() {}
}