java socket tcp/ip 简单示例

下面是client端代码

package ex3;
//200532580182 pengxu
import java.net.*;
import java.io.*;
public class TCPClient {
	//the client socket
  private Socket socket;
  //tcp connect port
  private int port=456;
//the round trip time
  private long[] rtt;
  //server
  private String remoteHost="localhost";
  //server ip
  private InetAddress remoteIP;
  //stream write to server
  private DataOutputStream outToServer;
  //stream receive from the server
  private BufferedReader inFromServer;
  //constructor
  public TCPClient(){
	  rtt=new long[1000];
	  try{
		  //get the host ip address
		  remoteIP=InetAddress.getByName(remoteHost);
		   
	  }catch(UnknownHostException e){
		  e.printStackTrace();
	  }
  }
  public void talk(){
	  try{
		  System.out.println("Client Start: ");
		  System.out.println("Establish TCP connections,please wait... ");
		  //begin to set 1000 TCP connection and send one byte at each connection
	  for(int i=0;i<1000;i++){
	     //record the tcp connect start time
		  long startTime=System.currentTimeMillis();
		  //connect to the server
		  socket=new Socket(remoteIP,port);
		  
	      outToServer=new DataOutputStream(socket.getOutputStream());
	      inFromServer=new BufferedReader(new InputStreamReader(socket.getInputStream()));
	      String msg="s";
	      //write data to the server
	      outToServer.writeBytes(msg);
	      char[] ch=new char[1];
	      //receive data from the server
	      inFromServer.read(ch);
	      //record the tcp connection finish time
	      long finishTime=System.currentTimeMillis();
	      //the rtt time of this tcp connection
	      rtt[i]=finishTime-startTime;	     
	      //close this tco connection
	      socket.close();
	  }
	  }catch(Exception e){
		  e.printStackTrace();
	  }
	  double sum=0;
	   //computer the average round trip time
	   for(int j=0;j<1000;j++){
		   sum+=rtt[j];
	   }
	   double rrtTime=sum/1000;
	   //print the rrt time
	   System.out.println("rrtTime: "+rrtTime+"ms");
  }
  public static void main(String [] args) throws Exception{
		new TCPClient().talk();
		
	}
}