Netty WriteAndFlush方法不起作用 [英] Netty WriteAndFlush method doesnt work

问题描述

看哪以下代码：

public final class SecureChatClient {

static final String HOST = System.getProperty("host", "127.0.0.1");
static final int PORT = Integer.parseInt(System.getProperty("port", "8992"));

public static void main(String[] args) throws Exception {
    // Configure SSL.
    final SslContext sslCtx = SslContext.newClientContext(InsecureTrustManagerFactory.INSTANCE);

    EventLoopGroup group = new NioEventLoopGroup();
    try {
        Bootstrap b = new Bootstrap();
        b.group(group)
         .channel(NioSocketChannel.class)
         .handler(new NetworkInitializer(sslCtx));

        // Start the connection attempt.
        Channel ch = b.connect(HOST, PORT).sync().channel();

        // Read commands from the stdin.
        ChannelFuture lastWriteFuture = null;
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        //does not work
        ch.writeAndFlush("hi");
        while (true) {
            String line = in.readLine();
         if (line == null) {
            break;
            //(goes to if writefuture !=null)
            }

            // Sends the received line to the server.
            lastWriteFuture = ch.writeAndFlush(line + "\r\n");

        }

        // Wait until all messages are flushed before closing the channel.
        if (lastWriteFuture != null) {
            lastWriteFuture.sync();
        }
    } finally {
        // The connection is closed automatically on shutdown.
        group.shutdownGracefully();
    }
}}

该代码是从netty的SecureChatClient Class http://netty.io/wiki/user-guide-for-4.x .html 添加成行

That code was modified from netty's SecureChatClient Class http://netty.io/wiki/user-guide-for-4.x.html with the added in line

            ch.writeAndFlush("hi");

。服务器上的输出不读取该行。我无法理解为什么会这样，对我而言，ch.writeandflush方法本身似乎不能在循环之外工作。

before the while loop. The output on the server does not read that line. I can't understand why that is, and to me it almost seems like the ch.writeandflush method itself doesn't work outside of a loop.

如果我不应该在循环之外使用ch.writeandlfush，有没有更好的方法在启动时向服务器发送消息？

If im not supposed to use ch.writeandlfush outside of a loop, is there any better way to send a message to a server on startup?

解决方案：所有writeandflush语句必须以\\结尾\\ r \\ n为了冲洗。他们没有冲洗。我不明白为什么会这样但是无论如何。

Solution: all writeandflush statements must end with "\r\n" in order to flush. With out that they dont flush. I don't understand why that is but whatever.

代码解决方案：ch.writeAndFlush（hi\r\ n）;

Code solution: ch.writeAndFlush("hi\r\n");

推荐答案

解决方案：所有writeandflush语句必须以\\\\ n结尾才能刷新。他们没有冲洗。我不明白为什么会这样但是无论如何。

Solution: all writeandflush statements must end with "\r\n" in order to flush. With out that they dont flush. I don't understand why that is but whatever.

代码解决方案：ch.writeAndFlush（hi\r\ n）;

Code solution: ch.writeAndFlush("hi\r\n");

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