com.athena.dolly.websocket.server.test.WebSocketServerHandler.java Source code

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/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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.
 */
package com.athena.dolly.websocket.server.test;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import io.netty.util.CharsetUtil;
import static io.netty.handler.codec.http.HttpHeaders.Names.*;
import static io.netty.handler.codec.http.HttpHeaders.*;
import static io.netty.handler.codec.http.HttpMethod.*;
import static io.netty.handler.codec.http.HttpResponseStatus.*;
import static io.netty.handler.codec.http.HttpVersion.*;

/**
 * Handles handshakes and messages
 */
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
    private static final Logger logger = LoggerFactory.getLogger(WebSocketServerHandler.class.getName());

    private static final String WEBSOCKET_PATH = "/websocket";

    private WebSocketServerHandshaker handshaker;

    private File destFile;
    private FileOutputStream fos;

    @Override
    public 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);
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    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;
        }

        // Send the demo page and favicon.ico
        if ("/".equals(req.getUri())) {
            ByteBuf content = WebSocketServerIndexPage.getContent(getWebSocketLocation(req));
            FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, OK, content);

            res.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
            setContentLength(res, content.readableBytes());

            sendHttpResponse(ctx, req, res);
            return;
        }
        if ("/favicon.ico".equals(req.getUri())) {
            FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND);
            sendHttpResponse(ctx, req, res);
            return;
        }

        // 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 void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {

        // Check for closing frame
        if (frame instanceof CloseWebSocketFrame) {
            handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
            try {
                fos.flush();
                fos.close();
                fos = null;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return;
        }
        if (frame instanceof PingWebSocketFrame) {
            ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
            return;
        }

        if (frame instanceof TextWebSocketFrame) {

            // Send the uppercase string back.
            String fileName = ((TextWebSocketFrame) frame).text();
            logger.debug(String.format("Received file name is [%s]", fileName));

            destFile = new File(fileName + ".received");
            try {
                fos = new FileOutputStream(destFile);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }

            ctx.channel().write(new TextWebSocketFrame(fileName.toUpperCase()));
        }

        if (frame instanceof BinaryWebSocketFrame) {
            byte[] buffer = null;
            ByteBuf rawMessage = ((BinaryWebSocketFrame) frame).content();

            //logger.debug(">>>> BinaryWebSocketFrame Found, " + rawMessage);
            // check if this ByteBuf is DIRECT (no backing byte[])
            if (rawMessage.hasArray() == false) {
                int size = rawMessage.readableBytes();
                buffer = new byte[size];
                rawMessage.readBytes(buffer);

                try {
                    fos.write(buffer);
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            } else {
                buffer = rawMessage.array();
            }
            logger.debug(">>>> Read Byte Array: " + buffer.length);

            return;
        }
    }

    private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest 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);
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }

    private static String getWebSocketLocation(FullHttpRequest req) {
        return "ws://" + req.headers().get(HOST) + WEBSOCKET_PATH;
    }
}