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This interface defines the socket stream connection.
A socket is accessed using a generic connection string with an explicit host
and port number. The host may be specified as a fully qualified host name or
IPv4 number.
e.g. socket://host.com:79
defines a target socket on the
host.com
system at
port 79
.
Note that RFC1900 recommends the use of names rather than IP numbers for best results in the event of IP number reassignment.
Every StreamConnection
provides a Connection
object as well as an InputStream
and OutputStream
to handle the I/O associated with the connection. Each of these interfaces
has its own close()
method. For systems that support
duplex communication over the socket connection, closing of the
input or output stream SHOULD shutdown just that side of the
connection. e.g. closing the InputStream
will permit the
OutputStream
to continue sending data.
Once the input or output stream has been closed, it can only be reopened
with a call to Connector.open()
. The application will receive
an IOException
if an attempt is made to reopen the stream.
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://"<hostport> |
<hostport> | ::= host ":" port |
<host> | ::= host name or IP address (omitted for inbound connections, See ServerSocketConnection) |
<port> | ::= numeric port number |
The following examples show how a SocketConnection
would be used to access a sample loopback program.
SocketConnection sc = (SocketConnection) Connector.open("socket://host.com:79"); sc.setSocketOption(SocketConnection.LINGER, 5); InputStream is = sc.openInputStream(); OutputStream os = sc.openOutputStream(); os.write("\r\n".getBytes()); int ch = 0; while(ch != -1) { ch = is.read(); } is.close(); os.close(); sc.close();
Field Summary | |
static byte |
DELAY
Socket option for the small buffer writing delay (0). |
static byte |
KEEPALIVE
Socket option for the keep alive feature (2). |
static byte |
LINGER
Socket option for the linger time to wait in seconds before closing a connection with pending data output (1). |
static byte |
RCVBUF
Socket option for the size of the receiving buffer (3). |
static byte |
SNDBUF
Socket option for the size of the sending buffer (4). |
Method Summary | |
String |
getAddress()
Gets the remote address to which the socket is bound. |
String |
getLocalAddress()
Gets the local address to which the socket is bound. |
int |
getLocalPort()
Returns the local port to which this socket is bound. |
int |
getPort()
Returns the remote port to which this socket is bound. |
int |
getSocketOption(byte option)
Get a socket option for the connection. |
void |
setSocketOption(byte option,
int value)
Set a socket option for the connection. |
Methods inherited from interface javax.microedition.io.InputConnection |
openDataInputStream, openInputStream |
Methods inherited from interface javax.microedition.io.Connection |
close |
Methods inherited from interface javax.microedition.io.OutputConnection |
openDataOutputStream, openOutputStream |
Field Detail |
public static final byte DELAY
public static final byte LINGER
public static final byte KEEPALIVE
public static final byte RCVBUF
public static final byte SNDBUF
Method Detail |
public void setSocketOption(byte option, int value) throws IllegalArgumentException, IOException
Options inform the low level networking code about intended usage patterns that the application will use in dealing with the socket connection.
Calling setSocketOption
to assign buffer sizes
is a hint to the platform of the sizes to set the underlying
network I/O buffers.
Calling getSocketOption
can be used to see what
sizes the system is using.
The system MAY adjust the buffer sizes to account for
better throughput available from Maximum Transmission Unit
(MTU) and Maximum Segment Size (MSS) data available
from current network information.
option
- socket option identifier (KEEPALIVE, LINGER,
SNDBUF, RCVBUF, or DELAY)value
- numeric value for specified optionIllegalArgumentException
- if the value is not
valid (e.g. negative value) or if the option
identifier is not validIOException
- if the connection was closedgetSocketOption(byte)
public int getSocketOption(byte option) throws IllegalArgumentException, IOException
option
- socket option identifier (KEEPALIVE, LINGER,
SNDBUF, RCVBUF, or DELAY)IllegalArgumentException
- if the option identifier is
not validIOException
- if the connection was closedsetSocketOption(byte, int)
public String getLocalAddress() throws IOException
The host address(IP number) that can be used to connect to this end of the socket connection from an external system. Since IP addresses may be dynamically assigned, a remote application will need to be robust in the face of IP number reasssignment.
The local hostname (if available) can be accessed from
System.getProperty("microedition.hostname")
IOException
- if the connection was closed.ServerSocketConnection
public int getLocalPort() throws IOException
IOException
- if the connection was closed.ServerSocketConnection
public String getAddress() throws IOException
IOException
- if the connection was closed.public int getPort() throws IOException
IOException
- if the connection was closed.
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