基于netty实现http客户端

导入netty4的依赖

<dependency>
	   <groupId>io.netty</groupId>
	   <artifactId>netty-all</artifactId>
	   <version>4.1.28.Final</version>
</dependency>

客户端

/**
 * 客户端
 */
public class Client {

    //线程组
    private static final EventLoopGroup group = new NioEventLoopGroup();

    //启动类
    private static final Bootstrap bootstrap = new Bootstrap();

    private static final int PORT = 6789;

    private static final String HOST = "127.0.0.1";

    public static void start() throws InterruptedException {

        try {
            bootstrap.group(group)
                    .remoteAddress(new InetSocketAddress(HOST, PORT))
                    //长连接
                    .option(ChannelOption.SO_KEEPALIVE, true)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer<Channel>() {
                        protected void initChannel(Channel channel) throws Exception {

                            //包含编码器和解码器
                            channel.pipeline().addLast(new HttpClientCodec());

                            //聚合
                            channel.pipeline().addLast(new HttpObjectAggregator(1024 * 10 * 1024));

                            //解压
                            channel.pipeline().addLast(new HttpContentDecompressor());

                            channel.pipeline().addLast(new ClientHandler());
                        }
                    });

            ChannelFuture channelFuture = bootstrap.connect().sync();

            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            group.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        Client.start();
    }
    
}

客户端处理器

/**
 * 客户端处理器
 */
public class ClientHandler extends ChannelInboundHandlerAdapter {


    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

        FullHttpResponse response = (FullHttpResponse) msg;

        ByteBuf content = response.content();
        HttpHeaders headers = response.headers();

        System.out.println("content:" + System.getProperty("line.separator") + content.toString(CharsetUtil.UTF_8));
        System.out.println("headers:" + System.getProperty("line.separator") + headers.toString());
    }


    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        URI url = new URI("/test");
        String meg = "hello";

        //配置HttpRequest的请求数据和一些配置信息
        FullHttpRequest request = new DefaultFullHttpRequest(
                HttpVersion.HTTP_1_0, HttpMethod.GET, url.toASCIIString(), Unpooled.wrappedBuffer(meg.getBytes("UTF-8")));

        request.headers()
                .set(HttpHeaderNames.CONTENT_TYPE, "text/plain;charset=UTF-8")
                //开启长连接
                .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE)
                //设置传递请求内容的长度
                .set(HttpHeaderNames.CONTENT_LENGTH, request.content().readableBytes());

        //发送数据
        ctx.writeAndFlush(request);
    }
}