79. The host can be discovered using the getLocalAddress method. The acceptAndOpen() method returns a SocketConnection instance. In addition to the normal StreamConnection behavior, the SocketConnection supports accessing the IP end point addresses of the live connection and access to socket options that control the buffering and timing delays associated with specific application usage of the connection.
Access to server socket connections may be restricted by the security policy of the device. Connector.open MUST check access for the initial server socket connection and acceptAndOpen MUST check before returning each new SocketConnection.
A server socket can be used to dynamically select an available port by omitting both the host and the port parameters in the connection URL string. For example, socket:// defines an inbound server socket on a port which is allocated by the system. To discover the assigned port number use the getLocalPort method.
The URI must conform to the BNF syntax specified below. If the URI does not conform to this syntax, an IllegalArgumentException is thrown.
| <socket_connection_string> | ::= "socket://" | "socket://"<hostport> |
| <hostport> | ::= host ":" port |
| <host> | ::= omitted for inbound connections, See SocketConnection |
| <port> | ::= numeric port number (omitted for system assigned port) |
The following examples show how a ServerSocketConnection would be used to access a sample loopback program.
// Create the server listening socket for port 1234 ServerSocketConnection scn = (ServerSocketConnection) Connector.open("socket://:1234"); // Wait for a connection. SocketConnection sc = (SocketConnection) scn.acceptAndOpen(); // Set application specific hints on the socket. sc.setSocketOption(DELAY, 0); sc.setSocketOption(LINGER, 0); sc.setSocketOption(KEEPALIVE, 0); sc.setSocketOption(RCVBUF, 128); sc.setSocketOption(SNDBUF, 128); // Get the input stream of the connection. DataInputStream is = sc.openDataInputStream(); // Get the output stream of the connection. DataOutputStream os = sc.openDataOutputStream(); // Read the input data. String result = is.readUTF(); // Echo the data back to the sender. os.writeUTF(result); // Close everything. is.close(); os.close(); sc.close(); scn.close(); ..
| |