Java套接字:我的服务器输入流不会从客户端输出流中读取？

Question

编辑:我很长,但有谁知道如何编程套接字？

我的问题让我有些困惑.我有一台服务器在一台计算机上运行而在另一台计算机上运行,​​我有一个客户端连接到它.当我从客户端键入消息到控制台并发送它时,服务器似乎没有收到它.任何人都知道为什么,因为我在过去3个小时内一直在测试打印到控制台,并且无法解决这个问题.我对套接字比较新,所以如果我只是个白痴,不要太苛刻.

继承了我的客户端代码:

import java.net.*;
import java.util.Scanner;
import java.io.*;

public class SocketClient {

public static void main(String [] args) {
    String host = "************";
    int port = 25565;

    StringBuffer instr = new StringBuffer();
    String TimeStamp;
    System.out.println("SocketClient initialized");

    try {
        InetAddress address = InetAddress.getByName(host);
        Socket connection = new Socket(address, port);

        BufferedOutputStream bos = new     BufferedOutputStream(connection.getOutputStream());
        OutputStreamWriter osw = new OutputStreamWriter(bos, "US-ASCII");

        Scanner scan = new Scanner(System.in);
        String message = scan.nextLine();

        TimeStamp = new java.util.Date().toString();
        String process = "Server called on " + host + ":" + port + " at " + TimeStamp + ": " + message + (char) 13;

        osw.write(process);
        osw.flush();

        BufferedInputStream bis = new BufferedInputStream(connection.getInputStream());

        InputStreamReader isr = new InputStreamReader(bis, "US-ASCII");

        int c;
        while ( (c = isr.read()) != 13)
            instr.append( (char) c);

        connection.close();
        System.out.println(instr);

    } catch (UnknownHostException e) {
        System.err.println("UnknownHostException: " + e);
    } catch (IOException e) {
        System.err.println("IOExcepion: " + e);
    }
}
}

以下是将客户端连接到服务器的代码:

import java.io.IOException;
import java.net.*;

public class MultipleSocketServer {

public static Socket connection;
public static String name = "Tyler's Server";
public static int limit = 2;
public static Thread[] clients = new Thread[limit];
public static int current = 0;
public static int port = 25565;
public static String[] connected = {"", ""};
public static ServerSocket socket;

public static void main(String[] args) {
    System.out.println("Server starting...");
    try {
        ServerSocket socket = new ServerSocket(port);
        while(true) {
            Socket connection = socket.accept();
            String ip = connection.getRemoteSocketAddress().toString().substring(1, 13);
            loop:
            for(int i = 0; i < connected.length; i++) {
                if(connected[0].equals(ip) || connected[1].equals(ip)) {
                    break loop;
                }else if(!connected[i].equals(ip)) {
                    connected[i] = ip;
                    System.out.println(ip);
                    MultiServer_Client client = new     MultiServer_Client(connection, i);
                    Thread run = new Thread(client);
                    run.start();
                    break loop;
                }
            }
        }
    } catch (IOException e1) {
        System.out.println("Could not bind server on: " + port);
        System.exit(-1);
    }
}
}

这是我的代码处理每个客户端连接:

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;

public class MultiServer_Client implements Runnable {

public String time;
public Socket client;
public StringBuffer process = new StringBuffer();

public BufferedInputStream inputStream;
public InputStreamReader reader;

public BufferedOutputStream outputStream;
public OutputStreamWriter writer;

public boolean connected = true;

public int ID;

public MultiServer_Client(Socket connection, int i) {
    client = connection;
    ID = i;
    try {
        inputStream = new BufferedInputStream(client.getInputStream());
        reader = new InputStreamReader(inputStream);

        outputStream = new BufferedOutputStream(client.getOutputStream());
        writer = new OutputStreamWriter(outputStream, "US-ASCII");
    } catch (IOException e) {
        System.out.println("IOException: " + e);
    }
    System.out.println("Client connected...");
    write("Connected to " + MultipleSocketServer.name);
}

public void run() {
    while(connected) {
        write("hi");
    }
    System.out.println("Disconnecting client...");
}

public void write(String authen) {
    try {
        time = new java.util.Date().toString();
        String message = time + ": " + authen + (char) 13;
        writer.write(message);
        writer.flush();
    } catch (IOException e) {
        connected = false;
        MultipleSocketServer.connected[ID] = "";
    }
}

public void read() {
    //read from client
    int character;
    process = new StringBuffer();
    try {
        while ((character = reader.read()) != 13) {
            process.append((char) character);
        }
        System.out.println(process);
        process.delete(0, process.length());
    } catch (IOException e) {
        connected = false;
        MultipleSocketServer.connected[ID] = "";
    }
}
}

如果我不能帮助Srry.正如我所说,我是套接字的新手,没有其他人似乎对此有任何问题...谢谢:)

Answer 1

您的代码的问题不是它的通信协议的"套接字".在服务器有机会写出"hi"之前,您正在有效地关闭套接字.

要调试它,您希望降低程序的复杂性.在您的计划中,有许多事情没有任何意义或问题.

所以,关于套接字的一点背景知识.有两种类型的套接字."ServerSocket"和"Socket"ServerSocket有点像秘书.它唯一的工作是听取呼叫,然后传递它们.这就是"接受"的作用.在任何客户端连接之前,accept()将阻塞,直到它收到连接.客户端连接后,accept返回表示连接的Socket.

常规Socket是所有工作发生的地方.您可以将其视为电话连接.您可以使用OutputStream远程与某人通话,并使用InputStream进行侦听.挑战在于您需要为两个套接字创建某种通信(称为协议)以进行通信.

您需要弄清楚如何划分命令.如果你想要一个"长度"分隔的协议,你可以传递一个固定长度的数字然后传递数据,或者你可以在消息的末尾使用一个特殊的字符(你现在拥有的).对于快速和脏,我经常使用后者与换行符.最简单的方法是使用PrintWriter进行书写,使用Scanner进行阅读.

下一步是找出客户端和服务器的通信模式.想想它是否来回传球.如果客户说了什么,另一方应该是倾听(反之亦然).

一旦找到协议和逻辑,您就可以将用于"处理"服务器端的逻辑移动到单独的线程(称为工作模式)中,以便服务器一次可以处理多个客户端.如果你想走得更远,你可以实现一个线程池的反应器,以使服务器不会耗尽线程,但是这可能是另一天/问题.

我建议遵循套接字上的Java教程:http://docs.oracle.com/javase/tutorial/networking/sockets/index.html