Package io.vertx.core.net

## Interface NetSocket

- All Superinterfaces:
    `ReadStream<Buffer>`, `StreamBase`, `WriteStream<Buffer>`

      public interface NetSocket
      extends ReadStream<Buffer>, WriteStream<Buffer>

  Represents a socket-like interface to a TCP connection on either the client or the server side.

  Instances of this class are created on the client side by an `NetClient` when a connection to a server is made, or on the server side by a `NetServer` when a server accepts a connection.

  It implements both `ReadStream` and `WriteStream` so it can be used with `Pipe` to pipe data with flow control.

  Author:
    Tim Fox

- - ### Method Summary

    All Methods Instance Methods Abstract Methods Default Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `applicationLayerProtocol()` |
    `Future<Void>` | `close()` | Close the socket
    `NetSocket` | `closeHandler​(Handler<Void> handler)` | Set a `handler` notified when the socket is closed
    `NetSocket` | `drainHandler​(Handler<Void> handler)` | Set a drain handler on the stream.
    `Future<Void>` | `end()` | Calls `close()`
    `NetSocket` | `endHandler​(Handler<Void> endHandler)` | Set an end handler.
    `NetSocket` | `exceptionHandler​(Handler<Throwable> handler)` | Set an exception handler on the read stream.
    `NetSocket` | `fetch​(long amount)` | Fetch the specified `amount` of elements.
    `NetSocket` | `handler​(Handler<Buffer> handler)` | Set a data handler.
    `String` | `indicatedServerName()` | Returns the SNI server name presented during the SSL handshake by the client.
    `boolean` | `isSsl()` |
    `SocketAddress` | `localAddress()` |
    `SocketAddress` | `localAddress​(boolean real)` | Like `localAddress()` ()} but returns the server local address when `real` is `true`
    `NetSocket` | `pause()` | Pause the `ReadStream`, it sets the buffer in `fetch` mode and clears the actual demand.
    `List<Certificate>` | `peerCertificates()` |
    `SocketAddress` | `remoteAddress()` |
    `SocketAddress` | `remoteAddress​(boolean real)` | Like `remoteAddress()` but returns the proxy remote address when `real` is `true`
    `NetSocket` | `resume()` | Resume reading, and sets the buffer in `flowing` mode.
    `default Future<Void>` | `sendFile​(String filename)` | Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system.
    `default Future<Void>` | `sendFile​(String filename, long offset)` | Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system.
    `Future<Void>` | `sendFile​(String filename, long offset, long length)` | Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system.
    `NetSocket` | `setWriteQueueMaxSize​(int maxSize)` | Set the maximum size of the write queue to `maxSize`.
    `NetSocket` | `shutdownHandler​(Handler<Void> handler)` | Set a `handler` notified when the socket is shutdown: the client or server will close the connection within a certain amount of time.
    `SSLSession` | `sslSession()` |
    `default Future<Void>` | `upgradeToSsl()` | Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options, without indicating a server name, without an upgrade message.
    `default Future<Void>` | `upgradeToSsl​(Buffer msg)` | Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options and without indicating a server name.
    `default Future<Void>` | `upgradeToSsl​(SSLOptions sslOptions)` | Upgrade channel to use SSL/TLS.
    `default Future<Void>` | `upgradeToSsl​(SSLOptions sslOptions, Buffer msg)` | Like `upgradeToSsl(SSLOptions, String, Buffer)` without indicating a server name
    `default Future<Void>` | `upgradeToSsl​(SSLOptions sslOptions, String serverName)` | Like `upgradeToSsl(SSLOptions, String, Buffer)` without an upgrade message.
    `Future<Void>` | `upgradeToSsl​(SSLOptions sslOptions, String serverName, Buffer upgrade)` | Upgrade the channel to use SSL/TLS, in other words proceeds to the TLS handshake.
    `default Future<Void>` | `upgradeToSsl​(String serverName)` | Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options and without an update message.
    `default Future<Void>` | `upgradeToSsl​(String serverName, Buffer msg)` | Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options.
    `Future<Void>` | `write​(String str)` | Write a `String` to the connection, encoded in UTF-8.
    `Future<Void>` | `write​(String str, String enc)` | Write a `String` to the connection, encoded using the encoding `enc`.
    `String` | `writeHandlerID()` | When a `NetSocket` is created, it may register an event handler with the event bus, the ID of that handler is given by `writeHandlerID`.

    - ### Methods inherited from interface io.vertx.core.streams.ReadStream

      `collect, pipe, pipeTo`

    - ### Methods inherited from interface io.vertx.core.streams.WriteStream

      `end, write, writeQueueFull`

- - ### Method Detail

    - #### exceptionHandler

          NetSocket exceptionHandler​(Handler<Throwable> handler)

      Description copied from interface: `ReadStream`
      Set an exception handler on the read stream.
      Specified by:
        `exceptionHandler` in interface `ReadStream<Buffer>`
      Specified by:
        `exceptionHandler` in interface `StreamBase`
      Specified by:
        `exceptionHandler` in interface `WriteStream<Buffer>`
      Parameters:
        `handler` - the exception handler
      Returns:
        a reference to this, so the API can be used fluently

    - #### handler

          NetSocket handler​(Handler<Buffer> handler)

      Description copied from interface: `ReadStream`
      Set a data handler. As data is read, the handler will be called with the data.
      Specified by:
        `handler` in interface `ReadStream<Buffer>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### pause

          NetSocket pause()

      Description copied from interface: `ReadStream`
      Pause the `ReadStream`, it sets the buffer in `fetch` mode and clears the actual demand.

      While it's paused, no data will be sent to the data `handler`.

      Specified by:
        `pause` in interface `ReadStream<Buffer>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### resume

          NetSocket resume()

      Description copied from interface: `ReadStream`
      Resume reading, and sets the buffer in `flowing` mode.

      If the `ReadStream` has been paused, reading will recommence on it.
      Specified by:
        `resume` in interface `ReadStream<Buffer>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### fetch

          NetSocket fetch​(long amount)

      Description copied from interface: `ReadStream`
      Fetch the specified `amount` of elements. If the `ReadStream` has been paused, reading will recommence with the specified `amount` of items, otherwise the specified `amount` will be added to the current stream demand.
      Specified by:
        `fetch` in interface `ReadStream<Buffer>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### endHandler

          NetSocket endHandler​(Handler<Void> endHandler)

      Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.

      This handler might be called after the close handler when the socket is paused and there are still buffers to deliver.

      Specified by:
        `endHandler` in interface `ReadStream<Buffer>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### setWriteQueueMaxSize

          NetSocket setWriteQueueMaxSize​(int maxSize)

      Description copied from interface: `WriteStream`
      Set the maximum size of the write queue to `maxSize`. You will still be able to write to the stream even if there is more than `maxSize` items in the write queue. This is used as an indicator by classes such as `Pipe` to provide flow control.

      The value is defined by the implementation of the stream, e.g in bytes for a `NetSocket`, etc...
      Specified by:
        `setWriteQueueMaxSize` in interface `WriteStream<Buffer>`
      Parameters:
        `maxSize` - the max size of the write stream
      Returns:
        a reference to this, so the API can be used fluently

    - #### drainHandler

          NetSocket drainHandler​(Handler<Void> handler)

      Description copied from interface: `WriteStream`
      Set a drain handler on the stream. If the write queue is full, then the handler will be called when the write queue is ready to accept buffers again. See `Pipe` for an example of this being used.

      The stream implementation defines when the drain handler, for example it could be when the queue size has been reduced to `maxSize / 2`.

      Specified by:
        `drainHandler` in interface `WriteStream<Buffer>`
      Parameters:
        `handler` - the handler
      Returns:
        a reference to this, so the API can be used fluently

    - #### writeHandlerID

          String writeHandlerID()

      When a `NetSocket` is created, it may register an event handler with the event bus, the ID of that handler is given by `writeHandlerID`.

      By default, no handler is registered, the feature must be enabled via `NetClientOptions.setRegisterWriteHandler(boolean)` or `NetServerOptions.setRegisterWriteHandler(boolean)`.

      Given this ID, a different event loop can send a buffer to that event handler using the event bus and that buffer will be received by this instance in its own event loop and written to the underlying connection. This allows you to write data to other connections which are owned by different event loops.

      Returns:
        the write handler ID
      See Also:
        `NetClientOptions.setRegisterWriteHandler(boolean)`, `NetServerOptions.setRegisterWriteHandler(boolean)`

    - #### write

          Future<Void> write​(String str)

      Write a `String` to the connection, encoded in UTF-8.
      Parameters:
        `str` - the string to write
      Returns:
        a future result of the write

    - #### write

          Future<Void> write​(String str,
                             String enc)

      Write a `String` to the connection, encoded using the encoding `enc`.
      Parameters:
        `str` - the string to write
        `enc` - the encoding to use
      Returns:
        a future completed with the result

    - #### sendFile

          default Future<Void> sendFile​(String filename)

      Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system. This is a very efficient way to stream files.
      Parameters:
        `filename` - file name of the file to send
      Returns:
        a future result of the send operation

    - #### sendFile

          default Future<Void> sendFile​(String filename,
                                        long offset)

      Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system. This is a very efficient way to stream files.
      Parameters:
        `filename` - file name of the file to send
        `offset` - offset
      Returns:
        a future result of the send operation

    - #### sendFile

          Future<Void> sendFile​(String filename,
                                long offset,
                                long length)

      Tell the operating system to stream a file as specified by `filename` directly from disk to the outgoing connection, bypassing userspace altogether (where supported by the underlying operating system. This is a very efficient way to stream files.
      Parameters:
        `filename` - file name of the file to send
        `offset` - offset
        `length` - length
      Returns:
        a future result of the send operation

    - #### remoteAddress

          SocketAddress remoteAddress()

      Returns:
        the remote address for this connection, possibly `null` (e.g a server bound on a domain socket). If `useProxyProtocol` is set to `true`, the address returned will be of the actual connecting client.

    - #### remoteAddress

          SocketAddress remoteAddress​(boolean real)

      Like `remoteAddress()` but returns the proxy remote address when `real` is `true`

    - #### localAddress

          SocketAddress localAddress()

      Returns:
        the local address for this connection, possibly `null` (e.g a server bound on a domain socket) If `useProxyProtocol` is set to `true`, the address returned will be of the proxy.

    - #### localAddress

          SocketAddress localAddress​(boolean real)

      Like `localAddress()` ()} but returns the server local address when `real` is `true`

    - #### end

          Future<Void> end()

      Calls `close()`
      Specified by:
        `end` in interface `WriteStream<Buffer>`
      Returns:
        a future completed with the result

    - #### close

          Future<Void> close()

      Close the socket
      Returns:
        a future completed with the result

    - #### closeHandler

          NetSocket closeHandler​(Handler<Void> handler)

      Set a `handler` notified when the socket is closed
      Parameters:
        `handler` - the handler
      Returns:
        a reference to this, so the API can be used fluently

    - #### shutdownHandler

          NetSocket shutdownHandler​(Handler<Void> handler)

      Set a `handler` notified when the socket is shutdown: the client or server will close the connection within a certain amount of time. This gives the opportunity to the `handler` to close the socket gracefully before the socket is closed.
      Parameters:
        `handler` - the handler notified
      Returns:
        a reference to this, so the API can be used fluently

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl()

      Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options, without indicating a server name, without an upgrade message.

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(Buffer msg)

      Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options and without indicating a server name.

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(String serverName)

      Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options and without an update message.

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(String serverName,
                                            Buffer msg)

      Like `upgradeToSsl(SSLOptions, String, Buffer)` with the default SSL options.

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(SSLOptions sslOptions,
                                            String serverName)

      Like `upgradeToSsl(SSLOptions, String, Buffer)` without an upgrade message.

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(SSLOptions sslOptions,
                                            Buffer msg)

      Like `upgradeToSsl(SSLOptions, String, Buffer)` without indicating a server name

    - #### upgradeToSsl

          Future<Void> upgradeToSsl​(SSLOptions sslOptions,
                                    String serverName,
                                    Buffer upgrade)

      Upgrade the channel to use SSL/TLS, in other words proceeds to the TLS handshake.

      The `upgrade` message will be sent after the socket is ready to proceed to the TLS handshake in order to avoid data races. In practice is usually send by a server when it sends a message to the client to proceed to the handshake, e.g. `250 STARTTLS` for an SMTP server, it should be `null` on a client

      The server name is sent in the client handshake, it should be `null` on a server.

      Be aware that for this to work SSL must be configured.

      Parameters:
        `sslOptions` - the SSL options
        `serverName` - the server name
        `upgrade` - the upgrade message to send
      Returns:
        a future completed when the connection has been upgraded to SSL

    - #### upgradeToSsl

          default Future<Void> upgradeToSsl​(SSLOptions sslOptions)

      Upgrade channel to use SSL/TLS. Be aware that for this to work SSL must be configured.
      Parameters:
        `sslOptions` - the SSL options
      Returns:
        a future completed when the connection has been upgraded to SSL

    - #### isSsl

          boolean isSsl()

      Returns:
        true if this `NetSocket` is encrypted via SSL/TLS.

    - #### sslSession

          SSLSession sslSession()

      Returns:
        SSLSession associated with the underlying socket. Returns null if connection is not SSL.
      See Also:
        `SSLSession`

    - #### peerCertificates

          List<Certificate> peerCertificates()
                                      throws SSLPeerUnverifiedException

      Returns:
        an ordered list of the peer certificates. Returns null if connection is not SSL.
      Throws:
        `SSLPeerUnverifiedException` - SSL peer's identity has not been verified.
      See Also:
        `SSLSession.getPeerCertificates()`, `sslSession()`

    - #### indicatedServerName

          String indicatedServerName()

      Returns the SNI server name presented during the SSL handshake by the client.
      Returns:
        the indicated server name

    - #### applicationLayerProtocol

          String applicationLayerProtocol()

      Returns:
        the application-level protocol negotiated during the TLS handshake