/**
* Copyright (C) 2011-2013 Barchart, Inc. <http://www.barchart.com/>
*
* All rights reserved. Licensed under the OSI BSD License.
*
* http://www.opensource.org/licenses/bsd-license.php
*/
package com.barchart.http.server;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.util.AttributeKey;
import com.barchart.http.request.RequestHandler;
import com.barchart.http.request.RequestHandlerMapping;
/**
* Netty channel handler for routing inbound requests to the proper
* RequestHandler.
*/
@Sharable
public class HttpRequestChannelHandler extends
ChannelInboundMessageHandlerAdapter<FullHttpRequest> {
public static final AttributeKey<PooledServerResponse> ATTR_RESPONSE =
new AttributeKey<PooledServerResponse>("response");
private final HttpServerConfig config;
private final ServerMessagePool messagePool;
public HttpRequestChannelHandler(final HttpServerConfig config_) {
super();
config = config_;
messagePool = new ServerMessagePool(config.maxConnections());
}
@Override
public void messageReceived(final ChannelHandlerContext ctx,
final FullHttpRequest msg) throws Exception {
// Create request handler
final RequestHandlerMapping mapping =
config.getRequestMapping(msg.getUri());
if (mapping == null) {
sendNotFound(ctx, msg);
return;
}
final String relativePath =
msg.getUri().substring(mapping.path().length());
// Create request/response
final PooledServerRequest request = messagePool.getRequest();
request.init(ctx.channel(), msg, relativePath);
final RequestHandler handler = mapping.handler(request);
final PooledServerResponse response = messagePool.getResponse();
response.init(ctx, this, handler, request, config.logger());
// Store in ChannelHandlerContext for future reference
ctx.attr(ATTR_RESPONSE).set(response);
try {
// Process request
handler.onRequest(request, response);
} catch (final Throwable t) {
// Catch server errors
response.setStatus(HttpResponseStatus.INTERNAL_SERVER_ERROR);
try {
config.errorHandler().onError(request, response, t);
} catch (final Throwable t2) {
response.write(t.getClass()
+ " was thrown while processing this request. Additionally, "
+ t2.getClass()
+ " was thrown while handling this exception.");
}
config.logger().error(request, response, t);
} finally {
// If handler did not request async response, finish request
if (!response.isFinished() && !response.isSuspended()) {
response.finish();
}
}
}
private void sendNotFound(final ChannelHandlerContext ctx,
final FullHttpRequest msg) throws Exception {
// Create request/response
final PooledServerRequest request = messagePool.getRequest();
request.init(ctx.channel(), msg, msg.getUri());
final PooledServerResponse response = messagePool.getResponse();
response.init(ctx, this, null, request, config.logger());
response.setStatus(HttpResponseStatus.NOT_FOUND);
// Store in ChannelHandlerContext for future reference
ctx.attr(ATTR_RESPONSE).set(response);
try {
// Process request
config.errorHandler().onError(request, response, null);
} catch (final Throwable e) {
response.write("The requested URL was not found. Additionally, "
+ e.getClass() + " was thrown while handling this error.");
} finally {
// If handler did not request async response, finish request
if (!response.isFinished() && !response.isSuspended()) {
response.finish();
}
}
}
@Override
public void channelInactive(final ChannelHandlerContext ctx) {
final PooledServerResponse response = ctx.attr(ATTR_RESPONSE).get();
if (response != null) {
try {
if (!response.isFinished()) {
response.close();
final RequestHandler handler = response.handler();
if (handler != null) {
handler.onAbort(response.request(), response);
}
}
} finally {
freeHandlers(ctx);
}
}
}
@Override
public void exceptionCaught(final ChannelHandlerContext ctx,
final Throwable exception) throws Exception {
final PooledServerResponse response = ctx.attr(ATTR_RESPONSE).get();
if (response != null) {
try {
try {
if (!response.isFinished()) {
response.setStatus(HttpResponseStatus.INTERNAL_SERVER_ERROR);
config.errorHandler().onError(response.request(),
response, exception);
response.close();
final RequestHandler handler = response.handler();
if (handler != null) {
handler.onException(response.request(), response,
exception);
}
}
} finally {
config.logger().error(response.request(), response,
exception);
}
} finally {
freeHandlers(ctx);
}
}
}
/**
* Free any request/response handlers related to the current channel handler
* context.
*/
public void freeHandlers(final ChannelHandlerContext ctx) {
final PooledServerResponse response =
ctx.attr(ATTR_RESPONSE).getAndRemove();
if (response != null) {
try {
final RequestHandler handler = response.handler();
if (handler != null) {
handler.onComplete(response.request(), response);
}
} finally {
messagePool.makeAvailable(response.request());
response.close();
messagePool.makeAvailable(response);
}
}
}
}