How to Set Up a Basic HTTP Server in Java?

In Java, setting up a basic HTTP server involves creating an application that listens for incoming HTTP requests and responses. In this article, we will discuss how to set up a basic HTTP server in Java.

Implementation Steps to Set Up a Basic HTTP Server

Step 1: Create an HttpServer instance.
Step 2: Create a context and set the handler.
Step 3: Start the server.
Step 4: Handle the request.

Program to Set up a Basic HTTP Server in Java

Below is the Program to Set up a Basic HTTP Server in Java:

Java

// Java Program to Set up a Basic HTTP Server
import com.sun.net.httpserver.HttpServer;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpExchange;

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;

// Driver Class
public class SimpleHttpServer 
{
    // Main Method
    public static void main(String[] args) 
    {
        try {
            // Create an HttpServer instance
            HttpServer server = HttpServer.create(new InetSocketAddress(8000), 0);

            // Create a context for a specific path and set the handler
            server.createContext("/", new MyHandler());

            // Start the server
            server.setExecutor(null); // Use the default executor
            server.start();

            System.out.println("Server is running on port 8000");
        } catch (IOException e) {
            System.out.println("Error starting the server: " + e.getMessage());
        }
    }

    // Define a custom HttpHandler
    static class MyHandler implements HttpHandler {
        @Override
        public void handle(HttpExchange exchange) throws IOException 
        {
            // Handle the request
            String response = "Hello, this is a simple HTTP server response!";
            exchange.sendResponseHeaders(200, response.length());
            OutputStream os = exchange.getResponseBody();
            os.write(response.getBytes());
            os.close();
        }
    }
}

Output:

Below the terminal output is showing that the server is running on port number 8000.

Output

Response:

Below we can see the response in browser.

Response in Browser

Explanation of the Code:

The above program is the example of the set up a basic HTTP server that can be runs into the port number 8000.
This server is created using HttpServer. First, an instance of HttpServer is created and assigned to a port number using InetSocketAddress.
Then create the new handler once completed the configuration add the response text then start the server.
The response message is handled in the MyHandler class, where the text "Hello, this is a simple HTTP server response!" is sent to the client.