java - 什么时候停止读取 telnet 输入？

Question

目前我有四个类(class) basic MUD client : WeatherDriver 用于主类，LineReader 用于处理 InputStream 和 LineParser 用于解析 String 的队列，而Connection 包含Apache telnet connection .这是基于 Apache Weather Telnet example .

LineReader 如何知道何时停止读取 InputStream 以向 WeatherDriver 发送消息以开始解析？

线阅读器:

package teln;

import static java.lang.System.out;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;

public class LineReader {

    private String prompt = "/[#]/";

    public LineReader() {
    }

    public Queue<String> readInputStream(InputStream inputStream) throws IOException {
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        StringBuilder sb = new StringBuilder();
        BufferedReader br = new BufferedReader(inputStreamReader);
        String line = br.readLine();

        Queue<String> lines = new LinkedList<>();
        while (line != null) { //never terminates...
            sb.append(line);
            line = br.readLine();
            lines.add(line);
        }
        out.println(lines);
        return lines;
    }

    public void setPrompt(String prompt) {
        this.prompt = prompt;  //need to determine EOL somehow...
    }
}

连接:

package teln;

import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.SocketException;
import org.apache.commons.net.telnet.TelnetClient;

public class Connection {

    private TelnetClient tc = new TelnetClient();

    public Connection() {
    }

    public Connection(InetAddress h, int p, String prompt) throws SocketException, IOException {
        tc.connect(h, p);
    }

    public InputStream getInputStream() {
        return tc.getInputStream();
    }
}

天气驱动器:

package teln;

import static java.lang.System.out;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Properties;
import java.util.Queue;

public final class WeatherDriver {

    private static Connection c;
    private static LineReader lineReader = new LineReader();
    private static LineParser lineParser = new LineParser();

    public static void main(String[] args) throws UnknownHostException, SocketException, IOException {
        Properties props = PropertiesReader.getProps();
        InetAddress host = InetAddress.getByName(props.getProperty("host"));
        int port = Integer.parseInt(props.getProperty("port"));
        String prompt = props.getProperty("prompt");
          out.println("connecting...");
        c = new Connection(host, port, prompt);
        InputStream inputStream = c.getInputStream();
        out.println("got stream");
        Queue<String> lines = lineReader.readInputStream(inputStream);
        out.println("got lines");
        lineParser.parseLines(lines);
        out.println("parsed lines");
    }
}

Answer 1

您的线路阅读器必须充分了解“协议(protocol)”，以检测控制终端的程序何时需要输入。 IE。必须有某种提示表明“线路转向”。当它检测到这一点时，它会停止读取并让您的前端执行下一步操作。

如果远程系统有不同的方式来指示它正在等待输入(不同类型的提示)并且如果您需要检测超时条件并采取一些特殊操作，这将变得复杂。

您可能会受益于绘制状态图，显示远程程序可能处于的各种状态，以及如何通过程序的输出将状态转换到 telnet session 。