HttpServerHandler.java

/*
 * Copyright 2013 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 io.jafka.http;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
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.FullHttpResponse;
import io.netty.handler.codec.http.HttpContent;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.LastHttpContent;
import io.netty.util.CharsetUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.ByteArrayOutputStream;
import java.util.HashMap;
import java.util.Map;

import static io.netty.handler.codec.http.HttpHeaders.Names.*;
import static io.netty.handler.codec.http.HttpResponseStatus.*;
import static io.netty.handler.codec.http.HttpVersion.*;

public class HttpServerHandler extends SimpleChannelInboundHandler<Object> {

    private Logger logger = LoggerFactory.getLogger(getClass());
    private HttpRequest request;
    final HttpServer server;
    public HttpServerHandler(HttpServer server){
        this.server = server;
    }
    /**
     * Buffer that stores the response content
     */
    //private final StringBuilder body = new StringBuilder();
    private ByteArrayOutputStream body;
    private Map<String,String> args = null;

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

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception{
        if (msg instanceof HttpRequest) {
            HttpRequest request = this.request = (HttpRequest) msg;

            if (HttpHeaders.is100ContinueExpected(request)) {
                send100Continue(ctx);
            }
            body = new ByteArrayOutputStream(64);
            args = new HashMap<String, String>(4);
            //
            if (request.getMethod() != HttpMethod.POST) {
                sendStatusMessage(ctx, HttpResponseStatus.METHOD_NOT_ALLOWED, "POST METHOD REQUIRED");
                return;
            }
            HttpHeaders headers = request.headers();
            String contentType = headers.get("Content-Type");
            // 处理 text or octstream
            String key = headers.get("key");
            key = key != null ? key : headers.get("request_key");
            args.put("key",key);
            args.put("topic",headers.get("topic"));
            args.put("partition",headers.get("partition"));
        }

        if (msg instanceof HttpContent) {
            HttpContent httpContent = (HttpContent) msg;

            ByteBuf content = httpContent.content();
            if (content.isReadable()) {
                //body.write(content.array());
                content.readBytes(body,content.readableBytes());
                //body.append(content.toString(CharsetUtil.UTF_8));
            }

            if (msg instanceof LastHttpContent) {
                //process request
                if(server.handler != null) {
                    server.handler.handle(args, body.toByteArray());
                }
                if (!writeResponse(ctx)) {
                    // If keep-alive is off, close the connection once the content is fully written.
                    ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
                }
                body = null;
                args = null;
            }
        }
    }


    private boolean writeResponse(ChannelHandlerContext ctx) {
        // Decide whether to close the connection or not.
        boolean keepAlive = HttpHeaders.isKeepAlive(request);
        // Build the response object.
        FullHttpResponse response = new DefaultFullHttpResponse(
                HTTP_1_1, OK,
                Unpooled.copiedBuffer("OK", CharsetUtil.UTF_8));

        response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");

        if (keepAlive) {
            // Add 'Content-Length' header only for a keep-alive connection.
            response.headers().set(CONTENT_LENGTH, response.content().readableBytes());
            // Add keep alive header as per:
            // - http://www.w3.org/Protocols/HTTP/1.1/draft-ietf-http-v11-spec-01.html#Connection
            response.headers().set(CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
        }

        // Write the response.
        ctx.write(response);

        return keepAlive;
    }

    private static void send100Continue(ChannelHandlerContext ctx) {
        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, CONTINUE);
        ctx.write(response);
    }

    private static void sendStatusMessage(ChannelHandlerContext ctx, HttpResponseStatus status, String msg) {
        FullHttpResponse response = new DefaultFullHttpResponse(
                HTTP_1_1, status,
                Unpooled.copiedBuffer(msg, CharsetUtil.UTF_8));
        response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");
        ctx.writeAndFlush(response);
        ctx.close();
    }

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