Netty HttpClient 发送请求后如何接收作为 FullHttpResponse 的响应

Question

我正在使用netty编写HttpClient。

下面是我的 HttpClientApplication

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.*;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import java.net.URI;

public class HttpHelloWorldClientApp {
    static final String URL = System.getProperty("url", "https://www.google.com/");

    public static void main(String[] args) throws Exception {
        URI uri = new URI(URL);
        String scheme = uri.getScheme() == null? "http" : uri.getScheme();
        String host = uri.getHost() == null? "127.0.0.1" : uri.getHost();
        int port = uri.getPort();
        if (port == -1) {
            if ("http".equalsIgnoreCase(scheme)) {
                port = 80;
            } else if ("https".equalsIgnoreCase(scheme)) {
                port = 443;
            }
        }

        if (!"http".equalsIgnoreCase(scheme) && !"https".equalsIgnoreCase(scheme)) {
            System.err.println("Only HTTP(S) is supported.");
            return;
        }

        // Configure SSL context if necessary.
        final boolean ssl = "https".equalsIgnoreCase(scheme);
        final SslContext sslCtx;
        if (ssl) {
            sslCtx = SslContextBuilder.forClient()
                    .trustManager(InsecureTrustManagerFactory.INSTANCE).build();
        } else {
            sslCtx = null;
        }

        // Configure the client.
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new HttpClientInitializer(sslCtx));

            // Make the connection attempt.
            Channel ch = b.connect(host, port).sync().channel();

            // Prepare the HTTP request.
            FullHttpRequest request = new DefaultFullHttpRequest(
                    HttpVersion.HTTP_1_1, HttpMethod.GET, uri.getRawPath(), Unpooled.EMPTY_BUFFER);
            request.headers().set(HttpHeaderNames.HOST, host);
            request.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE);
            request.headers().set(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);

            // Send the HTTP request.
            ChannelFuture cf = ch.writeAndFlush(request);

            // Wait for the server to close the connection.
            ch.closeFuture().sync();

            System.out.println(cf.get());

        } finally {
            // Shut down executor threads to exit.
            group.shutdownGracefully();
        }
    }
}

通道初始化代码是-

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpContentDecompressor;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.ssl.SslContext;

public class HttpClientInitializer extends ChannelInitializer<SocketChannel> {
    private final SslContext sslCtx;

    public HttpClientInitializer(SslContext sslCtx) {
        this.sslCtx = sslCtx;
    }

    @Override
    public void initChannel(SocketChannel ch) {
        ChannelPipeline p = ch.pipeline();

        // Enable HTTPS if necessary.
        if (sslCtx != null) {
            p.addLast(sslCtx.newHandler(ch.alloc()));
        }

        p.addLast(new HttpClientCodec());

        // Remove the following line if you don't want automatic content decompression.
        p.addLast(new HttpContentDecompressor());

        // Uncomment the following line if you don't want to handle HttpContents.
        p.addLast(new HttpObjectAggregator(1048576));

        p.addLast(new HttpClientHandler());
    }
}

HttpClientHandler 是 -

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.*;
import io.netty.util.CharsetUtil;

public class HttpClientHandler extends SimpleChannelInboundHandler<HttpObject> {
    @Override
    public void channelRead0(ChannelHandlerContext ctx, HttpObject msg) {
        if (msg instanceof HttpResponse response) {

            System.err.println("STATUS: " + response.status());
            System.err.println("VERSION: " + response.protocolVersion());
            System.err.println();

            if (!response.headers().isEmpty()) {
                for (CharSequence name: response.headers().names()) {
                    for (CharSequence value: response.headers().getAll(name)) {
                        System.err.println("HEADER: " + name + " = " + value);
                    }
                }
                System.err.println();
            }

            if (HttpUtil.isTransferEncodingChunked(response)) {
                System.err.println("CHUNKED CONTENT {");
            } else {
                System.err.println("CONTENT {");
            }
        }
        if (msg instanceof HttpContent content) {

            System.err.print(content.content().toString(CharsetUtil.UTF_8));
            System.err.flush();

            if (content instanceof LastHttpContent) {
                System.err.println("} END OF CONTENT");
                ctx.close();
            }
        }
    }

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

HttpClientHandler 正在打印主体的状态、标头和有效负载。 想要的是将

HttpContent

聚合为

FullHttpResponse

并在

main

类中的

HttpHelloWorldClientApp

函数中打印。

cf.get()

只是打印 null。

知道如何获得汇总响应吗？

Answer 1

你能接受吗

static FullHttpResponse content=null;
@Override
public void channelRead0(ChannelHandlerContext ctx, HttpObject msg) {
    FullHttpResponse fullHttpResponse = (FullHttpResponse) msg;
    content=fullHttpResponse;
}

main(){
 while (HttpClientHandler.content==null){
                Thread.sleep(100);
            }

            System.out.println("result==="+HttpClientHandler.content);
}

我不认为channel和HttpClientHandler有关系