Working with Networking

HttpClient client = HttpClient.newBuilder()
    .version(HttpClient.Version.HTTP_2)
    .connectTimeout(Duration.ofSeconds(10))
    .followRedirects(HttpClient.Redirect.NORMAL)
    .build();

HttpRequest req = HttpRequest.newBuilder()
    .uri(URI.create("https://api.example.com/users"))
    .header("Accept", "application/json")
    .timeout(Duration.ofSeconds(5))
    .GET()
    .build();

HttpResponse<String> res = client.send(req, BodyHandlers.ofString());
System.out.println(res.statusCode() + ": " + res.body());

HttpRequest req = HttpRequest.newBuilder()
    .uri(URI.create("https://api.example.com/users"))
    .header("Content-Type", "application/json")
    .POST(BodyPublishers.ofString("{\"name\":\"Alice\"}"))
    .build();

CompletableFuture<String> future = client
    .sendAsync(req, BodyHandlers.ofString())
    .thenApply(HttpResponse::body)
    .exceptionally(ex -> "ERROR: " + ex.getMessage());

try (ServerSocket server = new ServerSocket(8080)) {
    while (true) {
        try (Socket s = server.accept();
             var in = new BufferedReader(new InputStreamReader(s.getInputStream()));
             var out = new PrintWriter(s.getOutputStream(), true)) {
            String line;
            while ((line = in.readLine()) != null) out.println(line);
        }
    }
}

WebSocket ws = HttpClient.newHttpClient().newWebSocketBuilder()
    .buildAsync(URI.create("wss://example.com/socket"), new WebSocket.Listener() {
        public CompletionStage<?> onText(WebSocket ws, CharSequence data, boolean last) {
            System.out.println("Got: " + data);
            return null;
        }
    })
    .join();
ws.sendText("Hello", true);