0
0
Welcome to Java Socket programming example. Every server is a program that runs on a specific system and listens on a specific port. Sockets are bound to the port numbers and when we run any server it just listens on the socket and waits for client requests. For example, tomcat server running on port 8080 waits for client requests and once it gets any client request, it responds to them.
A socket is one endpoint of a two-way communication link between two programs running on the network. The socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent.
In java socket programming example tutorial, we will learn how to write java socket server and java socket client program. We will also learn how server client program read and write data on the socket.
java.net.Socket and java.net.ServerSocket are the java classes that implements Socket and Socket server.
MainServer.java
import java.io.*;
import java.net.*;
public class MyServer {
public static void main(String[] args){
try{
ServerSocket ss=new ServerSocket(7500);
Socket s=ss.accept();//establishes connection
DataInputStream dis=new DataInputStream(s.getInputStream());
String str=(String)dis.readUTF();
System.out.println("message= "+str);
ss.close();
}catch(Exception e){System.out.println(e);}
}
}
WClient.java
import java.io.*;
import java.net.*;
public class MyClient {
public static void main(String[] args) {
try{
Socket s=new Socket("localhost",7500);
DataOutputStream dout=new DataOutputStream(s.getOutputStream());
dout.writeUTF("Hello Server");
dout.flush();
dout.close();
s.close();
}catch(Exception e){System.out.println(e);}
}
} Example of Java Socket Programming (Read-Write both side)
MainServer.java
import java.io.*;
import java.net.*;
public class MyClient {
public static void main(String[] args) {
try{
Socket s=new Socket("localhost",6666);
DataOutputStream dout=new DataOutputStream(s.getOutputStream());
dout.writeUTF("Hello Server");
dout.flush();
dout.close();
s.close();
}catch(Exception e){System.out.println(e);}
}
} WClient.java
import java.net.*;
import java.io.*;
class MyClient{
public static void main(String args[])throws Exception{
Socket s=new Socket("localhost",3333);
DataInputStream din=new DataInputStream(s.getInputStream());
DataOutputStream dout=new DataOutputStream(s.getOutputStream());
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String str="",str2="";
while(!str.equals("stop")){
str=br.readLine();
dout.writeUTF(str);
dout.flush();
str2=din.readUTF();
System.out.println("Server says: "+str2);
}
dout.close();
s.close();
}} Notes to read about socket programming in java
About Author
Vicky Chhetri