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(); } }