我如何从Java套接字读取？

Question

我正在尝试从套接字发送和读取回复，但是没有运气。 到目前为止，我得到的是连接到服务器并读取连接答复（来自爱立信电信交换机的标题），并将其打印在System.out上。 我需要做的就是向交易所发送命令并获得回复，这就是我遇到的问题。 下面是我的测试代码。

任何帮助表示赞赏。

public class ExchangeClientSocket {

  public void run() {
      try {
        int serverPort = 23;
        InetAddress host = InetAddress.getByName("my.host.ip.address");
        Socket socket = new Socket(host, serverPort);

        InputStreamReader isr = new InputStreamReader(socket.getInputStream());
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(isr);

        int i;
        StringBuffer buffer = new StringBuffer();
        while (true) {
            i = in.read();
            if (i == 60) {
                break;
            } else {
                buffer.append((char) i);
            }
        }
        // this returns the head from exchange
        System.out.println(buffer.toString());

        out.write("allip;"); // command I want to send to exchange
        out.flush();

        System.out.println(in.ready()); // this returns false
        System.out.println(in.read());
        System.out.println("damn..");

        buffer = new StringBuffer();
        // can't get into this loop
        // this is where I want to read the allip response
        while ((i = in.read()) != -1) {
            i = in.read();
            if (i == 60) {
                break;
            } else {
                buffer.append((char) i);
            }
        }
        System.out.println(buffer.toString());

        out.close();
        in.close();
        socket.close();
      } catch (UnknownHostException ex) {
          ex.printStackTrace();
      } catch (IOException e) {
          e.printStackTrace();
      }
   }
}

Answer 1

这是关于在写入输出流后如何从服务器获取输入的建议： 只需从socket获取另一个输入流 。

因此，发送命令并读取后，您可以从套接字创建一个新的流，而不是从同一流中读取。

因此，我建议在这里将代码更改为此：

public void run() {
    try {
        int serverPort = 23;
        InetAddress host = InetAddress.getByName("my.host.ip.address");
        Socket socket = new Socket(host, serverPort);

        InputStreamReader isr = new InputStreamReader(socket.getInputStream());
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(isr);

        int i;
        StringBuffer buffer = new StringBuffer();
        while (true) {
            i = in.read();
            if (i == 60) {
                break;
            } else {
                buffer.append((char) i);
            }
        }
        // this returns the head from exchange
        System.out.println(buffer.toString());

        out.write("allip;"); // command I want to send to exchange
        out.flush();

        // Create a new input stream here !!!
        in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

        buffer = new StringBuffer();
        // can't get into this loop
        while ((i = in.read()) != -1) {
            i = in.read();
            if (i == 60) {
                break;
            } else {
                buffer.append((char) i);
            }
        }
        System.out.println(buffer.toString());

        out.close();
        in.close();
        socket.close();
    } catch (UnknownHostException ex) {
        ex.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}