Socket sk = new Socket("210.0.235.14",13);

InputStream inStream = sk.getInputStream();

try 
{ 
Socket sk = new Socket("210.0.235.14",13); 
sk.setSoTimeout(3000); 
  InputStream inStream = sk.getInputStream();
  //得到输入流对象 
  Scanner sc = new Scanner(inStream); 
  //将数据打印到控制台 
  while(sc.hasNextLine()) 
  { 
 String str = sc.nextLine(); 
 System.out.println("Output : " + str); 
  } 
  sk.close(); 
} 
catch(SocketTimeoutException e) //超时异常
{ 
  System.out.println("Time Out!"); 
} 
catch(Exception e) 
{ 
  e.printStackTrace(); 
}

new Socket(host,port);

Socket sk = new Socker();
sk.connect(new InetSocketAddress(host,port),2000);
//设置超时时间为2秒

package cls; 
import java.net.*; 
public class ShowIP 
{ 
  public static void main(String[] args) 
  { 
    try 
    { 
      if(args.length > 0) 
      { 
        String hostName = args[0]; //主机名 
        InetAddress[] addr = InetAddress.getAllByName(hostName);
        //得到该主机的所有地址 
        //打印输出至控制台 
        for(InetAddress address : addr) 
        { 
          System.out.println(address.getHostAddress()); 
        } 
      } 
      else 
      { 
        System.out.println(InetAddress.getLocalHost().getHostAddress());
      } 
    } 
    catch(Exception e) 
    { 
      e.printStackTrace(); 
    } 
  } 
}

ServerSocket sock = new ServerSocker(8000);

package cls; 
import java.io.*; 
import java.net.*; 
import java.util.*; 
public class ServerDemo 
{ 
  /** 
   * @param args 
   */ 
  public static void main(String[] args) 
  { 
    try 
    { 
      //ServerSocket servSocket = new ServerSocket(8000); 
      ServerSocket servSocket = new ServerSocket(8400); 
      int amount = 0; 
      while(true) 
      { 
        Socket client = servSocket.accept(); 
        ++amount; 
        Date time = new Date(); 
        String prompt = time.toString() + ": 第" + amount + "个用户 " + client.getInetAddress().getHostAddress() + " 已连接\n"; 
        System.out.print(prompt); //在控制台输出信息 
        ServerDemo.writeLog(prompt); //写入到文件中 
        //start a new Thread 
        Thread th = new Thread(new ServThread(client,amount)); 
        th.start(); 
      } 
    } 
    catch(Exception e) 
    { 
      e.printStackTrace(); 
    } 
  } 
  //写入日志文件 
  public static void writeLog(String str) 
  { 
    File logFile = new File("server-log.txt"); 
    try 
    { 
      FileWriter out = new FileWriter(logFile,true); 
      out.append(str); 
      out.close(); 
    } 
    catch(Exception e) 
    { 
      e.printStackTrace(); 
    } 
  } 
} 
/* 
 * 服务线程类 
 */ 
class ServThread implements Runnable 
{ 
  private Socket client; 
  private int ix; 
  public ServThread(Socket soc,int ix) 
  { 
    client = soc; 
    this.ix = ix; 
  } 
  public void run() 
  { 
    try 
    { 
      InputStream inStream = client.getInputStream(); 
      OutputStream outStream = client.getOutputStream(); 
      Scanner recv = new Scanner(inStream); 
      PrintWriter send = new PrintWriter(outStream,true); 
      send.println("欢迎～随便聊几句吧！[输入'bye'关闭联接]"); 
      while(recv.hasNextLine()) 
      { 
        String str = recv.nextLine(); 
        if(str.equals("bye")) 
        { 
          send.println("See you later ~ ^-^"); 
          break; 
        } 
        send.println("这是个测试程序，现在还没有什么功能哦"); 
      } 
      Date time = new Date(); 
      String prompt = time.toString() + ": 第" + ix + "个用户 " + client.getInetAddress().getHostAddress() + " 已断开连接\n"; 
      System.out.print(prompt); 
      ServerDemo.writeLog(prompt); //写入到文件中 
      client.close(); 
    } 
    catch(Exception e) 
    { 
      e.printStackTrace(); 
    } 
  } 
}