一个简单的服务器和客户机程序[Java编程]

//: JabberServer.java
// Very simple server that just
// echoes whatever the client sends.
import java.io.*;
import java.net.*;

public class JabberServer {  
  // Choose a port outside of the range 1-1024:
  public static final int PORT = 8080;
  public static void main(String[] args) 
      throws IOException {
    ServerSocket s = new ServerSocket(PORT);
    System.out.println("Started: " + s);
    try {
      // Blocks until a connection occurs:
      Socket socket = s.accept();
      try {
        System.out.println(
          "Connection accepted: "+ socket);
        BufferedReader in = 
          new BufferedReader(
            new InputStreamReader(
              socket.getInputStream()));
        // Output is automatically flushed
        // by PrintWriter:
        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);
          out.println(str);
        }
      // Always close the two sockets...
      } finally {
        System.out.println("closing...");
        socket.close();
      }
    } finally {
      s.close();
    }
  } 
} ///:~

ServerSocket[addr=0.0.0.0,PORT=0,localport=8080]
Socket[addr=127.0.0.1,PORT=1077,localport=8080]

//: JabberClient.java
// Very simple client that just sends
// lines to the server and reads lines
// that the server sends.
import java.net.*;
import java.io.*;

public class JabberClient {
  public static void main(String[] args) 
      throws IOException {
    // Passing null to getByName() produces the
    // special "Local Loopback" IP address, for
    // testing on one machine w/o a network:
    InetAddress addr = 
      InetAddress.getByName(null);
    // Alternatively, you can use 
    // the address or name:
    // InetAddress addr = 
    //    InetAddress.getByName("127.0.0.1");
    // InetAddress addr = 
    //    InetAddress.getByName("localhost");
    System.out.println("addr = " + addr);
    Socket socket = 
      new Socket(addr, JabberServer.PORT);
    // Guard everything in a try-finally to make
    // sure that the socket is closed:
    try {
      System.out.println("socket = " + socket);
      BufferedReader in =
        new BufferedReader(
          new InputStreamReader(
            socket.getInputStream()));
      // Output is automatically flushed
      // by PrintWriter:
      PrintWriter out =
        new PrintWriter(
          new BufferedWriter(
            new OutputStreamWriter(
              socket.getOutputStream())),true);
      for(int i = 0; i < 10; i ++) {
        out.println("howdy " + i);
        String str = in.readLine();
        System.out.println(str);
      }
      out.println("END");
    } finally {
      System.out.println("closing...");
      socket.close();
    }
  }
} ///:~