netty http client

http://www.cnblogs.com/luxiaoxun/p/3959450.html

基于Netty4的HttpServer和HttpClient的简单实现

Netty的主页: http://netty.io/index.html

使用的Netty的版本: netty-4.0.23.Final.tar.bz2 ‐ 15-Aug-2014 (Stable, Recommended)

Http 消息格式:

Http request:

Method path-to-resource HTTPVersion-number

Header-name-1: value1

Header-name-2: value2

Optional request body

Http response:

HTTP/Version-number response-code response-phrase

Header-name-1: value1

Header-name-2: value2

Optional response body

实现一个简单的Http请求及响应过程:

  1. Client向Server发送http请求。

  2. Server端对http请求进行解析。

  3. Server端向client发送http响应。

  4. Client对http响应进行解析。

Netty中Http request消息格式:

Netty中Http response消息格式:

代码实例:

Http Server:

package com.netty.test;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
public class HttpServer {
    private static Log log = LogFactory.getLog(HttpServer.class);
    public void start(int port) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
            .childHandler(new ChannelInitializer<SocketChannel>() {
                @Override
                public void initChannel(SocketChannel ch) throws Exception {
                    // server端发送的是httpResponse,所以要使用HttpResponseEncoder进行编码
                    ch.pipeline().addLast(new HttpResponseEncoder());
                    // server端接收到的是httpRequest,所以要使用HttpRequestDecoder进行解码
                    ch.pipeline().addLast(new HttpRequestDecoder());
                    ch.pipeline().addLast(new HttpServerInboundHandler());
                }
            }).option(ChannelOption.SO_BACKLOG, 128)
            .childOption(ChannelOption.SO_KEEPALIVE, true);
            ChannelFuture f = b.bind(port).sync();
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }
    public static void main(String[] args) throws Exception {
        HttpServer server = new HttpServer();
        log.info("Http Server listening on 8844 ...");
        server.start(8844);
    }
}

响应请求的HttpServerInboundHandler:

package com.netty.test;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
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.HttpHeaders.Values;
import io.netty.handler.codec.http.HttpRequest;
public class HttpServerInboundHandler extends ChannelInboundHandlerAdapter {
    private static Log log = LogFactory.getLog(HttpServerInboundHandler.class);
    private HttpRequest request;
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg)
    throws Exception {
        if (msg instanceof HttpRequest) {
            request = (HttpRequest) msg;
            String uri = request.getUri();
            System.out.println("Uri:" + uri);
        }
        if (msg instanceof HttpContent) {
            HttpContent content = (HttpContent) msg;
            ByteBuf buf = content.content();
            System.out.println(buf.toString(io.netty.util.CharsetUtil.UTF_8));
            buf.release();
            String res = "I am OK";
            FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1,
            OK, Unpooled.wrappedBuffer(res.getBytes("UTF-8")));
            response.headers().set(CONTENT_TYPE, "text/plain");
            response.headers().set(CONTENT_LENGTH,
            response.content().readableBytes());
            if (HttpHeaders.isKeepAlive(request)) {
                response.headers().set(CONNECTION, Values.KEEP_ALIVE);
            }
            ctx.write(response);
            ctx.flush();
        }
    }
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        log.error(cause.getMessage());
        ctx.close();
    }
}

Http Client:

按 Ctrl+C 复制代码

按 Ctrl+C 复制代码

处理Server响应的HttpClientInboundHandler:

按 Ctrl+C 复制代码

按 Ctrl+C 复制代码

log4j的配置:

# Root logger option
log4j.rootLogger=INFO, stdout, file
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
log4j.appender.file = org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File = logs/log.log
log4j.appender.file.Append = true
log4j.appender.file.Threshold = INFO
log4j.appender.file.layout = org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} %5p %c{1}:%L - %m%n

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