/**
* 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
* <p/>
* http://www.apache.org/licenses/LICENSE-2.0
* <p/>
* 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.hadoop.gateway.filter;
import java.io.IOException;
import java.util.Collection;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import org.apache.hadoop.gateway.GatewayMessages;
import org.apache.hadoop.gateway.config.GatewayConfig;
import org.apache.hadoop.gateway.i18n.messages.MessagesFactory;
import org.apache.hadoop.gateway.services.GatewayServices;
import org.apache.hadoop.gateway.services.topology.TopologyService;
import org.apache.hadoop.gateway.topology.Topology;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.handler.HandlerWrapper;
public class DefaultTopologyHandler extends HandlerWrapper {
private static final GatewayMessages LOG = MessagesFactory.get(GatewayMessages.class);
private GatewayConfig config;
private GatewayServices services;
private String staticRedirectContext = null;
public DefaultTopologyHandler( GatewayConfig config, GatewayServices services, Handler delegate ) {
if( config == null ) {
throw new IllegalArgumentException( "config==null" );
}
if( services == null ) {
throw new IllegalArgumentException( "services==null" );
}
this.config = config;
this.services = services;
String defaultTopologyName = config.getDefaultTopologyName();
if( defaultTopologyName != null ) {
staticRedirectContext = config.getDefaultAppRedirectPath();
if( staticRedirectContext != null && staticRedirectContext.trim().isEmpty() ) {
staticRedirectContext = null;
}
}
if( staticRedirectContext != null ) {
LOG.defaultTopologySetup( defaultTopologyName, staticRedirectContext );
}
setHandler( delegate );
}
@Override
public void handle( String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response ) throws IOException, ServletException {
if( !baseRequest.isHandled() ) {
String redirectContext = staticRedirectContext;
if( redirectContext == null ) {
TopologyService topologies = services.getService( GatewayServices.TOPOLOGY_SERVICE );
if( topologies != null ) {
Collection<Topology> candidates = topologies.getTopologies();
if( candidates != null && candidates.size() == 1 ) {
Topology topology = candidates.iterator().next();
redirectContext = "/" + config.getGatewayPath() + "/" + topology.getName();
}
}
}
if( redirectContext != null ) {
String newTarget = redirectContext + target;
ForwardedRequest newRequest = new ForwardedRequest( request, newTarget );
LOG.defaultTopologyForward( target, newTarget );
super.handle( newTarget, baseRequest, newRequest, response );
}
}
}
private static class ForwardedRequest extends HttpServletRequestWrapper {
private String contextPath;
public ForwardedRequest( HttpServletRequest request, String contextPath ) {
super( request );
this.contextPath = contextPath;
}
public String getContextPath() {
return contextPath;
}
}
}