java.net.ConnectException:连接被拒绝 [英] java.net.ConnectException: Connection refused

问题描述

我正在尝试实现 TCP 连接，从服务器端一切正常，但是当我运行客户端程序(从客户端计算机)时，出现以下错误:

I'm trying to implement a TCP connection, everything works fine from the server's side but when I run the client program (from client computer) I get the following error:

java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:432)
        at java.net.Socket.connect(Socket.java:529)
        at java.net.Socket.connect(Socket.java:478)
        at java.net.Socket.<init>(Socket.java:375)
        at java.net.Socket.<init>(Socket.java:189)
        at TCPClient.main(TCPClient.java:13)

我尝试更改套接字号以防它正在使用但无济于事，有谁知道是什么导致了此错误?如何修复它.

I tried changing the socket number in case it was in use but to no avail, does anyone know what is causing this error & how to fix it.

服务器代码:

//TCPServer.java

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

class TCPServer {
    public static void main(String argv[]) throws Exception {
        String fromclient;
        String toclient;

        ServerSocket Server = new ServerSocket(5000);

        System.out.println("TCPServer Waiting for client on port 5000");

        while (true) {
            Socket connected = Server.accept();
            System.out.println(" THE CLIENT" + " " + connected.getInetAddress()
                    + ":" + connected.getPort() + " IS CONNECTED ");

            BufferedReader inFromUser = new BufferedReader(
                    new InputStreamReader(System.in));

            BufferedReader inFromClient = new BufferedReader(
                    new InputStreamReader(connected.getInputStream()));

            PrintWriter outToClient = new PrintWriter(
                    connected.getOutputStream(), true);

            while (true) {

                System.out.println("SEND(Type Q or q to Quit):");
                toclient = inFromUser.readLine();

                if (toclient.equals("q") || toclient.equals("Q")) {
                    outToClient.println(toclient);
                    connected.close();
                    break;
                } else {
                    outToClient.println(toclient);
                }

                fromclient = inFromClient.readLine();

                if (fromclient.equals("q") || fromclient.equals("Q")) {
                    connected.close();
                    break;
                } else {
                    System.out.println("RECIEVED:" + fromclient);
                }

            }

        }
    }
}

客户代码:

//TCPClient.java

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

class TCPClient {
    public static void main(String argv[]) throws Exception {
        String FromServer;
        String ToServer;

        Socket clientSocket = new Socket("localhost", 5000);

        BufferedReader inFromUser = new BufferedReader(new InputStreamReader(
                System.in));

        PrintWriter outToServer = new PrintWriter(
                clientSocket.getOutputStream(), true);

        BufferedReader inFromServer = new BufferedReader(new InputStreamReader(
                clientSocket.getInputStream()));

        while (true) {

            FromServer = inFromServer.readLine();

            if (FromServer.equals("q") || FromServer.equals("Q")) {
                clientSocket.close();
                break;
            } else {
                System.out.println("RECIEVED:" + FromServer);
                System.out.println("SEND(Type Q or q to Quit):");

                ToServer = inFromUser.readLine();

                if (ToServer.equals("Q") || ToServer.equals("q")) {
                    outToServer.println(ToServer);
                    clientSocket.close();
                    break;
                } else {
                    outToServer.println(ToServer);
                }
            }
        }
    }
}

推荐答案

此异常意味着没有服务侦听您尝试连接的 IP/端口:

This exception means that there is no service listening on the IP/port you are trying to connect to:

• 您正在尝试连接到错误的 IP/主机或端口.
• 您尚未启动服务器.
• 您的服务器未侦听连接.
• 在 Windows 服务器上，侦听积压队列已满.

这篇关于java.net.ConnectException:连接被拒绝的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！