Socket

import java.net.*;
import java.io.*;
public class TestSocketServer{
public static void main(String [] args)throws Exception{
ServerSocket ss=new ServerSocket(6666);
while(true){
Socket s=ss.accept();
InputStream is=s.getInputStream();
DataInputStream dis=new DataInputStream(is);
String str=dis.readUTF();
System.out.println(str);
dis.close();
s.close();
}
}
}

import java.net.*;
import java.io.*;
public class TestSocketClient{
public static void main(String[]args)throws Exception{
Socket s=new Socket(“127.0.0.1”,6666);
OutputStream os=s.getOutputStream();
DataOutputStream dos=new DataOutputStream(os);
dos.writeUTF(“hello goodmorning”);
dos.flush();
dos.close();
s.close();
}
}

import java.net.*;
import java.io.*;
public class TestServer{
public static void main(String[]args)throws Exception{
ServerSocket ss=new ServerSocket(8888);
while(true){
Socket s=ss.accept();
OutputStream os=s.getOutputStream();
InputStream is=s.getInputStream();
DataOutputStream dos=new DataOutputStream(os);
DataInputStream dis=new DataInputStream(is);
String str=null;
if( (str=dis.readUTF()) !=null){
System.out.print(str);
System.out.print(“from:”+s.getInetAddress());
System.out.print(“port:”+s.getPort());
}
dos.writeUTF(“hey”);
dis.close();
dos.close();
s.close();

    }}

}

import java.net.*;
import java.io.*;
public class TestClient{
public static void main(String[]args)throws Exception{
Socket s=new Socket(“localhost”,8888);
InputStream is=s.getInputStream();
DataInputStream dis=new DataInputStream(is);
OutputStream os=s.getOutputStream();
DataOutputStream dos=new DataOutputStream(os);
dos.writeUTF(“Hello”);
String str=null;
if(( str=dis.readUTF())!=null){
System.out.println(str);
}
dis.close();
dos.close();
s.close();
}
}

import java.net.*;
public class TestUDPServer{
public static void main(String[]args)throws Exception{
byte[] bt=new byte[1024];
DatagramPacket dp=new DatagramPacket(bt,bt.length);
DatagramSocket ds=new DatagramSocket(5678);
while(true){
ds.receive(dp);
System.out.println(new String(bt,0,dp.getLength()));
}

}

}

import java.net.*;
public class TestUDPClient{
public static void main(String[]args)throws Exception{
DatagramSocket ds=new DatagramSocket(9999);
byte [] buf=(new String(“Hello”)).getBytes();
DatagramPacket dp=new DatagramPacket(buf,buf.length,new InetSocketAddress(“127.0.0.1”,5678));
ds.send(dp);
ds.close();
}
}