thinking in Java 中的一个例子?

import java.io.*;
import java.net.*;public class JabberSever{
  public static final int PORT = 8080;
  public static void main(String[] args)
      throw IOException {
    ServerSocket s = new SeverSocket(PORT);
    System.out.println("Started: " + s );
    try {
       Socket socket = s.accept();
       try {
           System.out.println(
              "Connection accepted: "+ socket);
           BufferedReader in = 
               new BufferedReader(
                  new InputStreamReader(
                     socket.getInputStream()));
           PrintWriter out =
               new PrintWriter(
                  new BufferedWriter(
                     new OutputStreamWriter(
                         socket.getOutputStream())),true);
            while (true) {
                String str = in.readLine();
                if (str.equals("END")) break;
                System.out.println("Echoing: " + str); //输出到控制台
                out.println(str); // 这个到底是将字符串输出到哪里？
            }
        }finally {
        System.out.println("closing...");
        socket.close();
        }
     }
}