AIM:
Program for
client-server socket.
THEORY:
A socket is one endpoint of a two-way
communication link between two programs running on the network. A socket is
bound to a port number so that the TCP layer can identify the application that
data is destined to be sent.Normally, a server runs on a specific computer and
has a socket that is bound to a specific port number. The server just waits,
listening to the socket for a client to make a connection request.
On the
client-side: The client knows the hostname of the machine on which the server
is running and the port number on which the server is listening. To make a
connection request, the client tries to rendezvous with the server on the
server's machine and port. The client also needs to identify itself to the
server so it binds to a local port number that it will use during this
connection. This is usually assigned by the system.
.
Running the Programs
You
must start the server program first. To do this, run the server program using
the Java interpreter, just as you would any other Java application. Remember to
run the server on the machine that the client program specifies when it creates
the socket.
Next, run
the client program. Note that you can run the client on any machine on your
network; it does not have to run on the same machine as the server.
If you are
too quick, you might start the client before the server has a chance to
initialize itself and begin listening on the port. If this happens, you will
see a stack trace from the client. If this happens, just restart the client.
CONCLUSION :
Sockets are the means by which
computers on a network communicate
PROGRAM:
Client Server Socket
//SERVER:
import java.io.*;
import java.net.*;
public class Server
{
public Server()
{}
public static void main(String args[])
{
try
{
String num1 = null;
ServerSocket server = new ServerSocket(8080);
Socket s= server.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter out = new PrintWriter(s.getOutputStream(),true);
num1 = in.readLine();
System.out.println("The requested integer number is: "+ num1);
int i=Integer.parseInt(num1);
out.println(Integer.toHexString(0x10000|i).substring(1).toUpperCase());
int binry[]= new int[8];
int octal[] = new int[4];
binaryconversion(binry,i);
octalconv(octal,i);
System.out.println();
num1=Integer.toString(binry[0]);
for(int p =1; p<8;p++)
{
num1=num1 + Integer.toString(binry[p]);
}
//binary number
out.println(num1);
num1=Integer.toString(octal[0]);
for(int p =1; p<4;p++)
{
num1=num1+Integer.toString(octal[p]);
}
//octal number
out.println(num1);
}
catch(IOException a)
{
System.out.println("Error in input");
}
}
public static void binaryconversion(int binry[], int i)
{
int k;
for(k=0;k<8;k++)
binry[k]=0;
k=7;
for(int a=i;a>0;)
{
binry[k]=a%2;
a=a/2;
k--;
}
}
public static void octalconv(int octal[], int i)
{
int k;
for(k=0;k<4;k++)
octal[k]=0;
k=3;
//SERVER:
import java.io.*;
import java.net.*;
public class Server
{
public Server()
{}
public static void main(String args[])
{
try
{
String num1 = null;
ServerSocket server = new ServerSocket(8080);
Socket s= server.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter out = new PrintWriter(s.getOutputStream(),true);
num1 = in.readLine();
System.out.println("The requested integer number is: "+ num1);
int i=Integer.parseInt(num1);
out.println(Integer.toHexString(0x10000|i).substring(1).toUpperCase());
int binry[]= new int[8];
int octal[] = new int[4];
binaryconversion(binry,i);
octalconv(octal,i);
System.out.println();
num1=Integer.toString(binry[0]);
for(int p =1; p<8;p++)
{
num1=num1 + Integer.toString(binry[p]);
}
//binary number
out.println(num1);
num1=Integer.toString(octal[0]);
for(int p =1; p<4;p++)
{
num1=num1+Integer.toString(octal[p]);
}
//octal number
out.println(num1);
}
catch(IOException a)
{
System.out.println("Error in input");
}
}
public static void binaryconversion(int binry[], int i)
{
int k;
for(k=0;k<8;k++)
binry[k]=0;
k=7;
for(int a=i;a>0;)
{
binry[k]=a%2;
a=a/2;
k--;
}
}
public static void octalconv(int octal[], int i)
{
int k;
for(k=0;k<4;k++)
octal[k]=0;
k=3;
for(int
a=i;a>0;)
{
octal[k]=a%8;
a=a/8;
k--;
}
}
}
OUTPUT
{
octal[k]=a%8;
a=a/8;
k--;
}
}
}
OUTPUT
The requested integer number is:
42
Client Server Socket
//CLIENT:
import java.io.*;
import java.net.*;
public class client
{
public client()
{}
public static void main(String args[])throws IOException
{
String num1 = null;
Socket s = new Socket("localhost",8080);
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the number for conversion : ");
num1 = br.readLine();
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter out = new PrintWriter(s.getOutputStream(),true);
out.println(num1);
num1 = in.readLine();
System.out.println("The HEX number is:" + num1);
num1 = in.readLine();
System.out.println("The binary number is:" + num1);
num1 = in.readLine();
System.out.println("The Octal number is:" + num1);
}
}
//CLIENT:
import java.io.*;
import java.net.*;
public class client
{
public client()
{}
public static void main(String args[])throws IOException
{
String num1 = null;
Socket s = new Socket("localhost",8080);
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the number for conversion : ");
num1 = br.readLine();
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
PrintWriter out = new PrintWriter(s.getOutputStream(),true);
out.println(num1);
num1 = in.readLine();
System.out.println("The HEX number is:" + num1);
num1 = in.readLine();
System.out.println("The binary number is:" + num1);
num1 = in.readLine();
System.out.println("The Octal number is:" + num1);
}
}
OUTPUT:
Enter the number for conversion :
42
The HEX number is:002A
The binary number is:00101010
The Octal number is:0052
42
The HEX number is:002A
The binary number is:00101010
The Octal number is:0052
Objective Questions:
1.Java uses ______ class representing a server and ______
class representing the client that uses TCP protocol.
2. ______ is used to
wait for accepting client connection requests.
3. In order to create a client socket connecting to a
particular server, the IP address must be given to the client socket,
otherwise, it cannot connect to the server: True or False.
4. Sockets provide an interface for programming networks at
the transport layer: True or False.
5. Java TCP Socket uses the InputStream/OutputStream to
read/write data to the network channel:
True or False.
6. Call Socket.close() method will close the TCP server that
socket connects to: True or False.
7. The socket instance does not need to be explicitly closed
to release all the resources it occupies, as the Java Garbage Collection
mechanism will do it automatically: True or False
8. The following line of code
Socket socket = new
Socket(“localhost,” 1254);
will create a TCP
server at localhost port 1254: True or False.
