Java provides built-in support for networking through its java.net package, enabling communication over TCP/IP protocols. This allows developers to write client-server applications, access web services, and manage sockets and URLs directly.

• java.net – Core networking APIs (Socket, ServerSocket, URL, HttpURLConnection)
• java.nio.channels – Non-blocking network channels
• java.net.http – Modern HTTP Client API (since Java 11)

Used for accessing resources over HTTP and other protocols.

URL url = new URL("https://example.com");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");

int status = con.getResponseCode();
System.out.println("Status Code: " + status);

A more modern and asynchronous HTTP client built on top of java.net.

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://example.com"))
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

For building lower-level client-server applications.

Server Side:

ServerSocket server = new ServerSocket(8080);
Socket client = server.accept();
InputStream in = client.getInputStream();
System.out.println("Client connected");

Client Side:

Socket socket = new Socket("localhost", 8080);
OutputStream out = socket.getOutputStream();
out.write("Hello".getBytes());

For connectionless communication with lower overhead.

DatagramSocket socket = new DatagramSocket();
InetAddress address = InetAddress.getByName("localhost");
byte[] buffer = "Ping".getBytes();
DatagramPacket packet = new DatagramPacket(buffer, buffer.length, address, 9999);
socket.send(packet);

• Building REST clients and calling web APIs
• Developing web servers and TCP/UDP-based services
• Real-time communication applications like chat, multiplayer games
• IoT and device communication

Java’s networking capabilities are broad — from simple HTTP calls to full-blown socket servers. The modern HttpClient makes HTTP-based communication much easier and robust, while low-level sockets are still powerful tools for custom protocols.