DefaultClientConnection

Closes this connection gracefully. This method will attempt to flush the transmitter's internal buffer prior to closing the underlying socket. This method MUST NOT be called from a different thread to force shutdown of the connection. Use shutdown instead.

Obtains the target host for this connection. If the connection is to a proxy but not tunnelled, this is the proxy. If the connection is tunnelled through a proxy, this is the target of the tunnel.
The return value is well-defined only while the connection is open. It may change even while the connection is open, because of an update.

Indicates whether this connection is secure. The return value is well-defined only while the connection is open. It may change even while the connection is open, because of an update.

Signals that the connection has been successfully open. An attempt to call this method on an open connection will cause an exception.

Signals that this connection is in the process of being open.
By calling this method, you can provide the connection with the unconnected socket that will be connected before openCompleted(boolean, HttpParams) is called. This allows the connection to close that socket if shutdown is called before it is open. Closing the unconnected socket will interrupt a thread that is blocked on the connect. Otherwise, that thread will either time out on the connect, or it returns successfully and then opens this connection which was just shut down.
You also must call openCompleted(boolean, HttpParams) in order to complete the process

Receives the request line and headers of the next response available from this connection. The caller should examine the HttpResponse object to find out if it should try to receive a response entity as well.

Sends the request line and all headers over the connection.

Force-closes this connection. If the connection is still in the process of being open (the method opening was already called but openCompleted was not), the associated socket that is being connected to a remote address will be closed. That will interrupt a thread that is blocked on connecting the socket. If the connection is not yet open, this will prevent the connection from being opened.

Updates this connection. A connection can be updated only while it is open. Updates are used for example when a tunnel has been established, or when a TLS/SSL connection has been layered on top of a plain socket connection.
Note: Updating the connection will not close the previously used socket. It is the caller's responsibility to close that socket if it is no longer required.