# HttpServer class

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.dartlang.org contains a set of high-level classes that, together with this class, makes it easy to provide content through HTTP servers.

Implements
  - Stream<HttpRequest>

## Constructors

HttpServer.listenOn(ServerSocket serverSocket)
  Attaches the HTTP server to an existing ServerSocket. When the HttpServer is closed, the HttpServer will just detach itself, closing current connections but not closing `serverSocket`.
  factory

## Properties

address → InternetAddress
  Returns the address that the server is listening on. This can be used to get the actual address used, when the address is fetched by a lookup from a hostname.
  read-only
autoCompress ↔ bool
  Whether the `HttpServer` should compress the content, if possible. [...]
  read / write
defaultResponseHeaders → HttpHeaders
  Default set of headers added to all response objects. [...]
  read-only
idleTimeout ↔ Duration
  Gets or sets the timeout used for idle keep-alive connections. If no further request is seen within `idleTimeout` after the previous request was completed, the connection is dropped. [...]
  read / write
port → int
  Returns the port that the server is listening on. This can be used to get the actual port used when a value of 0 for `port` is specified in the bind or bindSecure call.
  read-only
serverHeader ↔ String
  Gets and sets the default value of the `Server` header for all responses generated by this `HttpServer`. [...]
  read / write
sessionTimeout ← int
  Sets the timeout, in seconds, for sessions of this HttpServer. The default timeout is 20 minutes.
  write-only
first → Future<HttpRequest>
  The first element of the stream. [...]
  read-only, inherited
hashCode → int
  The hash code for this object. [...]
  read-only, inherited
isBroadcast → bool
  Whether this stream is a broadcast stream.
  read-only, inherited
isEmpty → Future<bool>
  Whether this stream contains any elements. [...]
  read-only, inherited
last → Future<HttpRequest>
  The last element of this stream. [...]
  read-only, inherited
length → Future<int>
  The number of elements in this stream. [...]
  read-only, inherited
runtimeType → Type
  A representation of the runtime type of the object.
  read-only, inherited
single → Future<HttpRequest>
  The single element of this stream. [...]
  read-only, inherited

## Methods

close({bool force: false }) → Future
  Permanently stops this HttpServer from listening for new connections. This closes the Stream of HttpRequests with a done event. The returned future completes when the server is stopped. For a server started using bind or bindSecure this means that the port listened on no longer in use. [...]
connectionsInfo() → HttpConnectionsInfo
  Returns an HttpConnectionsInfo object summarizing the number of current connections handled by the server.
any(bool test(T element)) → Future<bool>
  Checks whether `test` accepts any element provided by this stream. [...]
  inherited
asBroadcastStream({void onListen(StreamSubscription<T> subscription), void onCancel(StreamSubscription<T> subscription) }) → Stream<HttpRequest>
  Returns a multi-subscription stream that produces the same events as this. [...]
  inherited
asyncExpand<E>(Stream<E> convert(T event)) → Stream<E>
  Transforms each element into a sequence of asynchronous events. [...]
  inherited
asyncMap<E>(FutureOr<E> convert(T event)) → Stream<E>
  Creates a new stream with each data event of this stream asynchronously mapped to a new event. [...]
  inherited
cast<R>() → Stream<R>
  Adapt this stream to be a `Stream<R>`. [...]
  inherited
contains(Object needle) → Future<bool>
  Returns whether `needle` occurs in the elements provided by this stream. [...]
  inherited
distinct([bool equals(T previous, T next) ]) → Stream<HttpRequest>
  Skips data events if they are equal to the previous data event. [...]
  inherited
drain<E>([E futureValue ]) → Future<E>
  Discards all data on the stream, but signals when it's done or an error occurred. [...]
  inherited
elementAt(int index) → Future<HttpRequest>
  Returns the value of the `index`th data event of this stream. [...]
  inherited
every(bool test(T element)) → Future<bool>
  Checks whether `test` accepts all elements provided by this stream. [...]
  inherited
expand<S>(Iterable<S> convert(T element)) → Stream<S>
  Transforms each element of this stream into a sequence of elements. [...]
  inherited
firstWhere(bool test(T element), { HttpRequest orElse() }) → Future<HttpRequest>
  Finds the first element of this stream matching `test`. [...]
  inherited
fold<S>(S initialValue, S combine(S previous, T element)) → Future<S>
  Combines a sequence of values by repeatedly applying `combine`. [...]
  inherited
forEach(void action(T element)) → Future
  Executes `action` on each element of the stream. [...]
  inherited
handleError(Function onError, { bool test(dynamic error) }) → Stream<HttpRequest>
  Creates a wrapper Stream that intercepts some errors from this stream. [...]
  inherited
join([String separator = "" ]) → Future<String>
  Combines the string representation of elements into a single string. [...]
  inherited
lastWhere(bool test(T element), { HttpRequest orElse() }) → Future<HttpRequest>
  Finds the last element in this stream matching `test`. [...]
  inherited
listen(void onData(T event), { Function onError, void onDone(), bool cancelOnError }) → StreamSubscription<HttpRequest>
  Adds a subscription to this stream. [...]
  inherited
map<S>(S convert(T event)) → Stream<S>
  Transforms each element of this stream into a new stream event. [...]
  inherited
noSuchMethod(Invocation invocation) → dynamic
  Invoked when a non-existent method or property is accessed. [...]
  inherited
pipe(StreamConsumer<HttpRequest> streamConsumer) → Future
  Pipes the events of this stream into `streamConsumer`. [...]
  inherited
reduce(HttpRequest combine(T previous, T element)) → Future<HttpRequest>
  Combines a sequence of values by repeatedly applying `combine`. [...]
  inherited
singleWhere(bool test(T element), { HttpRequest orElse() }) → Future<HttpRequest>
  Finds the single element in this stream matching `test`. [...]
  inherited
skip(int count) → Stream<HttpRequest>
  Skips the first `count` data events from this stream. [...]
  inherited
skipWhile(bool test(T element)) → Stream<HttpRequest>
  Skip data events from this stream while they are matched by `test`. [...]
  inherited
take(int count) → Stream<HttpRequest>
  Provides at most the first `count` data events of this stream. [...]
  inherited
takeWhile(bool test(T element)) → Stream<HttpRequest>
  Forwards data events while `test` is successful. [...]
  inherited
timeout(Duration timeLimit, { void onTimeout(EventSink<T> sink) }) → Stream<HttpRequest>
  Creates a new stream with the same events as this stream. [...]
  inherited
toList() → Future<List<HttpRequest>>
  Collects all elements of this stream in a List. [...]
  inherited
toSet() → Future<Set<HttpRequest>>
  Collects the data of this stream in a Set. [...]
  inherited
toString() → String
  Returns a string representation of this object.
  inherited
transform<S>(StreamTransformer<HttpRequest, S> streamTransformer) → Stream<S>
  Applies a StreamTransformer to the current stream. [...]
  inherited
where(bool test(T event)) → Stream<HttpRequest>
  Creates a new stream from this stream that discards some elements. [...]
  inherited

## Operators

operator ==(dynamic other) → bool
  The equality operator. [...]
  inherited

## Static Methods

bind(dynamic address, int port, { int backlog: 0, bool v6Only: false, bool shared: false }) → Future<HttpServer>
  Starts listening for HTTP requests on the specified `address` and `port`. [...]
bindSecure(dynamic address, int port, SecurityContext context, { int backlog: 0, bool v6Only: false, bool requestClientCertificate: false, bool shared: false }) → Future<HttpServer>
  The `address` can either be a String or an InternetAddress. If `address` is a String, bind will perform a InternetAddress.lookup and use the first value in the list. To listen on the loopback adapter, which will allow only incoming connections from the local host, use the value InternetAddress.loopbackIPv4 or InternetAddress.loopbackIPv6. To allow for incoming connection from the network use either one of the values InternetAddress.anyIPv4 or InternetAddress.anyIPv6 to bind to all interfaces or the IP address of a specific interface. [...]