import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
+/**
+ * {@link WebSocketServerHandler} is implementation of
+ * {@link SimpleChannelInboundHandler} which allow handle
+ * {@link FullHttpRequest} and {@link WebSocketFrame} messages.
+ */
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
- private static final Logger logger = LoggerFactory.getLogger(WebSocketServerHandler.class);
-
- private WebSocketServerHandshaker handshaker;
-
- @Override
- protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
- if (msg instanceof FullHttpRequest) {
- handleHttpRequest(ctx, (FullHttpRequest) msg);
- } else if (msg instanceof WebSocketFrame) {
- handleWebSocketFrame(ctx, (WebSocketFrame) msg);
- }
- }
-
- private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req)
- throws Exception {
- // Handle a bad request.
- if (!req.getDecoderResult().isSuccess()) {
- sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
- return;
- }
-
- // Allow only GET methods.
- if (req.getMethod() != GET) {
- sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
- return;
- }
-
- String streamName = Notificator.createStreamNameFromUri(req.getUri());
- ListenerAdapter listener = Notificator.getListenerFor(streamName);
- if (listener != null) {
- listener.addSubscriber(ctx.channel());
- logger.debug("Subscriber successfully registered.");
- } else {
- logger.error("Listener for stream with name '{}' was not found.", streamName);
- sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, INTERNAL_SERVER_ERROR));
- }
-
- // Handshake
- WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
- getWebSocketLocation(req), null, false);
- handshaker = wsFactory.newHandshaker(req);
- if (handshaker == null) {
- WebSocketServerHandshakerFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel());
- } else {
- handshaker.handshake(ctx.channel(), req);
- }
-
- }
-
- private static void sendHttpResponse(ChannelHandlerContext ctx,
- HttpRequest req, FullHttpResponse res) {
- // Generate an error page if response getStatus code is not OK (200).
- if (res.getStatus().code() != 200) {
- ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
- res.content().writeBytes(buf);
- buf.release();
- setContentLength(res, res.content().readableBytes());
- }
-
- // Send the response and close the connection if necessary.
- ChannelFuture f = ctx.channel().writeAndFlush(res);
- if (!isKeepAlive(req) || res.getStatus().code() != 200) {
- f.addListener(ChannelFutureListener.CLOSE);
- }
- }
-
- private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) throws IOException {
- if (frame instanceof CloseWebSocketFrame) {
- handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
- String streamName = Notificator.createStreamNameFromUri(((CloseWebSocketFrame) frame).reasonText());
- ListenerAdapter listener = Notificator.getListenerFor(streamName);
- if (listener != null) {
- listener.removeSubscriber(ctx.channel());
- logger.debug("Subscriber successfully registered.");
- }
- Notificator.removeListenerIfNoSubscriberExists(listener);
- return;
- } else if (frame instanceof PingWebSocketFrame) {
- ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
- return;
- }
- }
-
- @Override
- public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
- throws Exception {
- if (cause instanceof java.nio.channels.ClosedChannelException == false) {
- //cause.printStackTrace();
- }
- ctx.close();
- }
-
- private static String getWebSocketLocation(HttpRequest req) {
- return "http://" + req.headers().get(HOST) + req.getUri();
- }
+ private static final Logger logger = LoggerFactory
+ .getLogger(WebSocketServerHandler.class);
+
+ private WebSocketServerHandshaker handshaker;
+
+ @Override
+ protected void channelRead0(ChannelHandlerContext ctx, Object msg)
+ throws Exception {
+ if (msg instanceof FullHttpRequest) {
+ handleHttpRequest(ctx, (FullHttpRequest) msg);
+ } else if (msg instanceof WebSocketFrame) {
+ handleWebSocketFrame(ctx, (WebSocketFrame) msg);
+ }
+ }
+
+ /**
+ * Checks if HTTP request method is GET and if is possible to decode HTTP
+ * result of request.
+ *
+ * @param ctx
+ * ChannelHandlerContext
+ * @param req
+ * FullHttpRequest
+ */
+ private void handleHttpRequest(ChannelHandlerContext ctx,
+ FullHttpRequest req) throws Exception {
+ // Handle a bad request.
+ if (!req.getDecoderResult().isSuccess()) {
+ sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1,
+ BAD_REQUEST));
+ return;
+ }
+
+ // Allow only GET methods.
+ if (req.getMethod() != GET) {
+ sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1,
+ FORBIDDEN));
+ return;
+ }
+
+ String streamName = Notificator.createStreamNameFromUri(req.getUri());
+ ListenerAdapter listener = Notificator.getListenerFor(streamName);
+ if (listener != null) {
+ listener.addSubscriber(ctx.channel());
+ logger.debug("Subscriber successfully registered.");
+ } else {
+ logger.error("Listener for stream with name '{}' was not found.",
+ streamName);
+ sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1,
+ INTERNAL_SERVER_ERROR));
+ }
+
+ // Handshake
+ WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
+ getWebSocketLocation(req), null, false);
+ handshaker = wsFactory.newHandshaker(req);
+ if (handshaker == null) {
+ WebSocketServerHandshakerFactory
+ .sendUnsupportedWebSocketVersionResponse(ctx.channel());
+ } else {
+ handshaker.handshake(ctx.channel(), req);
+ }
+
+ }
+
+ /**
+ * Checks response status, send response and close connection if necessary
+ *
+ * @param ctx
+ * ChannelHandlerContext
+ * @param req
+ * HttpRequest
+ * @param res
+ * FullHttpResponse
+ */
+ private static void sendHttpResponse(ChannelHandlerContext ctx,
+ HttpRequest req, FullHttpResponse res) {
+ // Generate an error page if response getStatus code is not OK (200).
+ if (res.getStatus().code() != 200) {
+ ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(),
+ CharsetUtil.UTF_8);
+ res.content().writeBytes(buf);
+ buf.release();
+ setContentLength(res, res.content().readableBytes());
+ }
+
+ // Send the response and close the connection if necessary.
+ ChannelFuture f = ctx.channel().writeAndFlush(res);
+ if (!isKeepAlive(req) || res.getStatus().code() != 200) {
+ f.addListener(ChannelFutureListener.CLOSE);
+ }
+ }
+
+ /**
+ * Handles web socket frame.
+ *
+ * @param ctx
+ * {@link ChannelHandlerContext}
+ * @param frame
+ * {@link WebSocketFrame}
+ */
+ private void handleWebSocketFrame(ChannelHandlerContext ctx,
+ WebSocketFrame frame) throws IOException {
+ if (frame instanceof CloseWebSocketFrame) {
+ handshaker.close(ctx.channel(),
+ (CloseWebSocketFrame) frame.retain());
+ String streamName = Notificator
+ .createStreamNameFromUri(((CloseWebSocketFrame) frame)
+ .reasonText());
+ ListenerAdapter listener = Notificator.getListenerFor(streamName);
+ if (listener != null) {
+ listener.removeSubscriber(ctx.channel());
+ logger.debug("Subscriber successfully registered.");
+ }
+ Notificator.removeListenerIfNoSubscriberExists(listener);
+ return;
+ } else if (frame instanceof PingWebSocketFrame) {
+ ctx.channel().write(
+ new PongWebSocketFrame(frame.content().retain()));
+ return;
+ }
+ }
+
+ @Override
+ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
+ throws Exception {
+ if (cause instanceof java.nio.channels.ClosedChannelException == false) {
+ // cause.printStackTrace();
+ }
+ ctx.close();
+ }
+
+ /**
+ * Get web socket location from HTTP request.
+ *
+ * @param req
+ * HTTP request from which the location will be returned
+ * @return String representation of web socket location.
+ */
+ private static String getWebSocketLocation(HttpRequest req) {
+ return "http://" + req.headers().get(HOST) + req.getUri();
+ }
}
Code Review / controller.git / blobdiff