Java socket client example

Java socket client example

Here is a simple example of a Java Socket Client:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
public class SocketClient {
public static void main(String[] args) throws IOException {
// Define the server's IP address and port
String serverIP = "localhost";
int serverPort = 1234;
// Create a socket object
Socket socket = new Socket(serverIP, serverPort);
// Get the input and output streams
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
// Send data to the server
String message = "Hello from client!";
out.println(message);
System.out.println("Client sent: " + message);
// Receive data from the server
String response;
while ((response = in.readLine()) != null) {
System.out.println("Server response: " + response);
}
// Close the socket
socket.close();
}
}

This Java program demonstrates a basic client-server communication using Socket programming. Here's what it does:

Note: This code assumes that there is a corresponding server-side Java program running at the specified IP address and port number. For example, you could use the following Java server-side code:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class SocketServer {
public static void main(String[] args) throws IOException {
// Define the port for our server
int port = 1234;
// Create a ServerSocket object
ServerSocket server = new ServerSocket(port);
// Wait for client connection
System.out.println("Waiting for client...");
Socket socket = server.accept();
// Get the input and output streams
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
// Receive data from client
String message;
while ((message = in.readLine()) != null) {
System.out.println("Received: " + message);
// Send response back to the client
out.println("Hello, " + message + "!");
}
// Close the socket and server
socket.close();
server.close();
}
}

This code runs a simple echo server that receives messages from clients, prints them to the console, and sends responses back.

Remember: For this example to work, both the client and server programs need to be run simultaneously.

ServerSocket Java example

Here is a simple ServerSocket example written in Java:

In this example, we are creating a basic server that listens for incoming connections on port 8000.

import java.net.*;
import java.io.*;
public class SocketServer {
public static void main(String[] args) throws Exception {
ServerSocket serverSocket = new ServerSocket(8000);
System.out.println("Server is listening...");
// Run indefinitely until a termination request.
while (true) {
Socket clientSocket = serverSocket.accept();
System.out.println("Connection accepted");
// Get the client's IP address and port number.
InetAddress clientAddress = clientSocket.getInetAddress();
int clientPort = clientSocket.getPort();
// Create a new thread to handle the client request.
Thread t = new ClientThread(clientSocket);
t.start();
}
}
static class ClientThread extends Thread {
Socket clientSocket;
public ClientThread(Socket s) {
this.clientSocket = s;
}
public void run() {
try {
// Read from the client's socket.
BufferedReader reader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println("Received message from client: " + line);
// Do something with the received data.
// Here, we are just sending it back to the client.
PrintWriter writer = new PrintWriter(clientSocket.getOutputStream(), true);
writer.println(line);
}
} catch (IOException e) {
System.out.println("Exception caught while reading from socket");
e.printStackTrace();
} finally {
try {
this.clientSocket.close();
} catch (IOException e) {
System.out.println("Error closing the socket");
e.printStackTrace();
}
}
}
}
}

Here's a breakdown of what each part does:

ServerSocket example is quite basic and may need additional error handling or additional logic based on your specific requirements.

I hope this helps!