//single one to one client
import java.io.*;
import java.net.*;
/*
Simple client using Java Sockets.
*/
public class SimpleClient {
/*
@param args
*/
public static void main(String[] args) {
// create a socket and find it to the host/port server is listening on.
String host;
int port;
if(args.length==0) {
host = “localhost”;
port = 9999;
} else {
host = args[0];
String portStr = args[1];
try {
port = Integer.parseInt(portStr);
} catch (NumberFormatException nfe) {
System.out.println(“Whoops, invalid port number. Will default to 9999”);
port = 9999;
}
}
try {
System.out.println(“Client will attempt connecting to server at host=”+ host +” port=”+ port +”.”);
Socket skt = new Socket(host,port);
// ok, got a connection. Let’s use java.io.* niceties to read and write from the connection.
BufferedReader myInput = new BufferedReader(new InputStreamReader(skt.getInputStream()));
BufferedReader consoleInput = new BufferedReader(new InputStreamReader(System.in));
PrintStream myOutput = new PrintStream(skt.getOutputStream());
boolean done = false;
while (!done) {
// prompt and read from console
System.out.print(“Enter a message, or enter “done” to quit: “);
String buf = consoleInput.readLine();
if(buf != null) {
if(buf.equalsIgnoreCase(“done”)) {
done = true;
} else {
// write something to the server.
myOutput.println(buf);
// see if the server echoes it back.
buf = myInput.readLine();
if(buf != null) {
System.out.println(“Client received [“+ buf + “] from the server!”);
}
}
} else {
done = true;
}
}
// we’re done, let’s get out of dodge!
skt.close();
System.out.println(“Client is exiting.”);
} catch (IOException ex) {
ex.printStackTrace();
System.out.println(“Whoops, something bad happened! I’m outta here.”);
}
}}
//single one to one server
import java.io.*;
import java.net.*;
/*
Simple server using Java Sockets.
*/
public class SimpleServer implements Runnable{
Socket csocket;
SimpleServer(Socket csocket){
this.csocket = csocket;
}
public static void main(String[] args) {
try {
// First we create a server socket and bind it to port 9999.
ServerSocket myServerSocket = new ServerSocket(9999);
// server processes incoming client connections forever…
while (true) {
// wait for an incoming connection…
System.out.println(“Server is waiting for an incoming connection on host=”);
System.out.print(InetAddress.getLocalHost().getCanonicalHostName()+” port=”+ myServerSocket.getLocalPort());
Socket skt = myServerSocket.accept();
new Thread(new SimpleServer(skt)).start();
}
} catch (IOException ex) {
ex.printStackTrace();
System.out.println(“Whoops, something bad happened! I’m outta here.”);
}
}
public void run(){
try{
// ok, got a connection. Let’s use java.io. niceties to read and write from the connection.
BufferedReader inputFromClient = new BufferedReader(new InputStreamReader(csocket.getInputStream()));
PrintStream outputToClient = new PrintStream(csocket.getOutputStream());
boolean connectionClosed = false;
while(!connectionClosed) {
// attempt to read input from the stream.
String buf = inputFromClient.readLine();
// if we got input, print it out and write a message back to the remote client..
if (buf != null) {
System.out.println(“Server read: [“+ buf + “]”);
outputToClient.println(buf);
} else {
connectionClosed = true;
}
}
// close the connection.
csocket.close();
System.out.println(“Connection to client closed. Server is now going to wait for another connection.”);
} catch (IOException ex) {
ex.printStackTrace();
System.out.println(“Whoops, something bad happened! I’m outta here.”);
}
}
}
