如何修改此代码以允许我的客户端套接字程序将字符串发送到服务器？

Question

Hi ive written some code to connect to a server through the use of a socket. Id like to write some simple code that allows me to send a string to the server, im assuming this will involve input and output streams but I am new to this. Ive put the code I am working with below, any insights into the best way to accomplish this would be great.

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

public class SocketMarket
{
   public static void main(String [] args)
   {
      String serverName = "XX.X.X.XXX";
      int port = XXXX;

      try
      {
         System.out.println("Connecting to " + serverName + " on port " + port);
         Socket client = new Socket(serverName, port);

         System.out.println("Connected to " + client.getRemoteSocketAddress());        
      }

      catch(IOException e)
      {
         e.printStackTrace();
      }       
   }
}

Thanks in advance

Answer 1

client.getOutputStream().write("Hello World".getBytes());
client.getOutputStream().flush();

The above is how you would send just a String , but you will probably want to build up some infrastructure around sending arbitrary text.

The general idea is that your server and client will communicate with each other using InputStream 's and OutputStream 's, which can be accessed from a Socket via getInputStream() and getOutputStream() , once the connection between them is made.

For your server to receive connections, you should be using a ServerSocket to accept() incoming connections.

Answer 2

Insight is here, the "really big index" for java.

http://docs.oracle.com/javase/tutorial/networking/sockets/readingWriting.html

Answer 3

Yes, it involves OutputStream s. If you want to output String s you could write raw bytes via the OutputStream you get from the connection but then you completely loose control over encoding. You need to learn about reader/writer/streams first, then networking via sockets is simple. You can find the relevant part of the Java tutorials here: http://docs.oracle.com/javase/tutorial/essential/io/ (you can ignore the NIO part completely for the beginning). After that you can learn about socket networking: http://docs.oracle.com/javase/tutorial/networking/sockets/index.html .