第一个java网络程序，有客户端和服务器端，用socket实现

1：服务器端程序 EchoServer

 

package com.capinfotech.network;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class EchoServer {

 private int port = 8000;
 private ServerSocket serverSocket;
 
 public EchoServer() throws IOException {
  serverSocket = new ServerSocket(port);     //初始化ServerSocket
  System.out.println("服务器启动");
 }
 /*
  * 组装数据
  */
 public String echo(String msg) {
  return "echo:" + msg;
 }
 
 /*
  * 获得PrintWriter对象
  */
 private PrintWriter getWriter(Socket socket) {
  try {
   OutputStream socketOut = socket.getOutputStream();
   PrintWriter pw = new PrintWriter(socketOut, true);  //参数true表示每写一行，PrintWriter缓存就自动溢出，把数据写到目的地
   return pw;
  } catch (IOException e) {
   e.printStackTrace();
  }
  return null;
 }
 
 /*
  * 获得BufferedReader对象
  */
 private BufferedReader getReader(Socket socket) throws IOException {
  InputStream is = socket.getInputStream();
  return new BufferedReader(new InputStreamReader(is));
 }
 
 public void service() throws IOException {
  while(true) {
   Socket socket = null;
   try {
    socket = serverSocket.accept();     //等待客户连接

   //输出客户端的IP和端口号
    System.out.println("New Connection accepted" + socket.getInetAddress() + ":" + socket.getPort());       PrintWriter pw = getWriter(socket);
    BufferedReader br = getReader(socket);
    String msg = null;
    while((msg = br.readLine()) != null) {
     System.out.println(msg);
     pw.println(echo(msg));
     if(msg.equals("bye")) {
      break;
     }
    }
   } catch(Exception e) {
    e.printStackTrace();
   } finally {
    if(socket != null) {
     socket.close();
    }
   }
  }
 }
 
 public static void main(String[] args) {
  try {
   new EchoServer().service();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}

2：客户端程序EchoClient.java

 

package com.capinfotech.network;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class EchoClient {

 private String localhost = "localhost";
 private int port = 8000;
 private Socket socket;
 
 public EchoClient() throws UnknownHostException, IOException {
  socket = new Socket(localhost, port);      //初始化Socket
 }
 
 private PrintWriter getWriter(Socket socket) throws IOException {
  OutputStream socketOut = socket.getOutputStream();
  return new PrintWriter(socketOut, true);  //参数true表示每写一行，PrintWriter缓存就自动溢出，把数据写到目的地
 }
 
 private BufferedReader getReader(Socket socket) throws IOException {
  InputStream socketIn = socket.getInputStream();
  BufferedReader br = new BufferedReader(new InputStreamReader(socketIn));
  return br;
 }
 
 public void talk() throws IOException {
  try {
   PrintWriter pw = getWriter(socket);
   BufferedReader br = getReader(socket);
   BufferedReader br_in = new BufferedReader(new InputStreamReader(System.in));  //获得系统的输入流（和标准输入有关）
   String msg = null;
   while((msg = br_in.readLine()) != null) {
    pw.println(msg);
    System.out.println(br.readLine());      //输出服务器端传过来的程序
    if(msg.equals("bye")) {
     break;
    }
   }
  } catch(Exception e) {
   e.printStackTrace();
  } finally {
   if(socket != null) {
    socket.close();
   }
  }
 }
 
 public static void main(String[] args) throws UnknownHostException, IOException {
  new EchoClient().talk();
 }
}