java - 使用本地主机上的套接字发送消息

Question

我正在本地计算机上通过套接字进行消息传递。我正在尝试向自己发送消息，这正在模仿我通过互联网发送的消息。不管怎样，我之前就遇到过绑定(bind)异常，但看来我可能已经克服了这个问题。现在我得到了:

 Exception in thread "main" java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at class2.main(class2.java:10)

如何让此连接正常工作并传递我的消息。这是我的程序中的两个类:

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;


public class IPMessenger {
    public static void main(String[] args) throws IOException{
        ServerSocket SC = new ServerSocket(4800);
        Socket socket = SC.accept();
        DataInputStream in = new DataInputStream(socket.getInputStream());
        DataOutputStream out = new DataOutputStream(socket.getOutputStream());
        System.out.println(in.readDouble());
        System.out.println("hi");
    //  out.writeChars("hello");
    }
}

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;


public class class2 {
    public static void main(String[] args) throws UnknownHostException, IOException{
        Socket sock = new Socket("localhost",4800);
        DataInputStream in = new DataInputStream(sock.getInputStream());
        DataOutputStream out = new DataOutputStream(sock.getOutputStream());
        out.writeDouble(5);
       //System.out.println(in.readChar());
    }
}

Answer 1

java.net.ConnectException: Connection refused: connect

当您运行客户端时，您的服务器并未运行。