/*
* Copyright (C) 2010 Google Inc.
*
* 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 com.google.greaze.server;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.greaze.definition.ErrorReason;
import com.google.greaze.definition.WebServiceSystemException;
import com.google.greaze.server.filters.GreazeFilter;
import com.google.greaze.server.filters.GreazeFilterChain;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.ProvisionException;
import com.google.inject.Singleton;
import com.google.inject.name.Named;
/**
* An dispatcher servlet that receives JSON web-service requests
*
* @author Inderjeet Singh
*/
@Singleton
@SuppressWarnings("serial")
public class GreazeDispatcherServlet extends HttpServlet {
private static final Logger log = Logger.getLogger(GreazeDispatcherServlet.class.getSimpleName());
private GreazeFilterChain filters;
@Inject
public GreazeDispatcherServlet(Injector injector, @Named("resource-prefix") String resourcePrefix,
GreazeFilterChain filtersToBeInstalled) {
this.filters = filtersToBeInstalled == null
? new GreazeFilterChain() : filtersToBeInstalled.copyOf();
this.filters.install(new RequestServicingFilter());
for (GreazeFilter filter : this.filters.getFilters()) {
filter.init(injector, resourcePrefix);
}
}
@Override
public void service(HttpServletRequest req, HttpServletResponse res) throws IOException {
try {
try {
try {
for (GreazeFilter filter : filters.getFilters()) {
boolean continueFilterChain = filter.service(req, res);
if (!continueFilterChain) {
break;
}
}
} catch (ProvisionException e) {
Exception cause = (Exception) e.getCause();
throw cause;
}
} catch (Exception e) {
if (e instanceof WebServiceSystemException) {
throw (WebServiceSystemException) e;
} else {
throw new WebServiceSystemException(ErrorReason.SERVER_UNAVAILABLE, e);
}
}
} catch (WebServiceSystemException e) {
ErrorReason reason = e.getReason();
String reasonStr = reason.toString();
log.log(Level.WARNING, reasonStr, e);
res.setHeader(ErrorReason.HTTP_RESPONSE_HEADER_NAME, reasonStr);
res.sendError(reason.getResponseCode(), e.getLocalizedMessage());
}
}
}