HttpServer class Null safety

A server that delivers content, such as web pages, using the HTTP protocol.

The HttpServer is a Stream that provides HttpRequest objects. Each HttpRequest has an associated HttpResponse object. The server responds to a request by writing to that HttpResponse object. The following example shows how to bind an HttpServer to an IPv6 InternetAddress on port 80 (the standard port for HTTP servers) and how to listen for requests. Port 80 is the default HTTP port. However, on most systems accessing this requires super-user privileges. For local testing consider using a non-reserved port (1024 and above).

import 'dart:io';

main() {
  HttpServer
      .bind(InternetAddress.anyIPv6, 80)
      .then((server) {
        server.listen((HttpRequest request) {
          request.response.write('Hello, world!');
          request.response.close();
        });
      });
}

Incomplete requests, in which all or part of the header is missing, are ignored, and no exceptions or HttpRequest objects are generated for them. Likewise, when writing to an HttpResponse, any Socket exceptions are ignored and any future writes are ignored.

The HttpRequest exposes the request headers and provides the request body, if it exists, as a Stream of data. If the body is unread, it is drained when the server writes to the HttpResponse or closes it.

Bind with a secure HTTPS connection

Use bindSecure to create an HTTPS server.

The server presents a certificate to the client. The certificate chain and the private key are set in the SecurityContext object that is passed to bindSecure.

import 'dart:io';
import "dart:isolate";

main() {
  SecurityContext context = new SecurityContext();
  var chain =
      Platform.script.resolve('certificates/server_chain.pem')
      .toFilePath();
  var key =
      Platform.script.resolve('certificates/server_key.pem')
      .toFilePath();
  context.useCertificateChain(chain);
  context.usePrivateKey(key, password: 'dartdart');

  HttpServer
      .bindSecure(InternetAddress.anyIPv6,
                  443,
                  context)
      .then((server) {
        server.listen((HttpRequest request) {
          request.response.write('Hello, world!');
          request.response.close();
        });
      });
}

The certificates and keys are PEM files, which can be created and managed with the tools in OpenSSL.

Connect to a server socket

You can use the listenOn constructor to attach an HTTP server to a ServerSocket.

import 'dart:io';

main() {
  ServerSocket.bind(InternetAddress.anyIPv6, 80)
    .then((serverSocket) {
      HttpServer httpserver = new HttpServer.listenOn(serverSocket);
      serverSocket.listen((Socket socket) {
        socket.write('Hello, client.');
      });
    });
}

Other resources

• HttpServer is a Stream. Refer to the Stream class for information about the streaming qualities of an HttpServer. Pausing the subscription of the stream, pauses at the OS level.

• The shelf package on pub.dev contains a set of high-level classes that, together with this class, makes it easy to provide content through HTTP servers.