totalcross.net

Class ServerSocket

java.lang.Object

totalcross.net.ServerSocket

public class ServerSocket
extends java.lang.Object

ServerSocket is a TCP/IP network server socket.

Under Java and Windows CE, if no network is present, the socket constructor may hang for an extended period of time due to the implementation of sockets in the underlying OS. This is a known problem.

Here is an example showing the server accepting a client connection and writing/reading some data to/from it:

 ServerSocket server = new ServerSocket(1024);
 Socket client = server.accept();
 byte[] bytes = "HELLO WORLD".getBytes();
 client.writeBytes(bytes, 0, bytes.length);
 byte[] buf = new byte[10];
 int count = client.readBytes(buf, 0, buf.length);
 if (count == buf.length)
    ...
 client.close();
 server.close();
 

Important: you cannot open a server socket before the main event loop. In other words, you cannot open a socket in the app's constructor, but CAN in the initUI method.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_BACKLOG The default backlog value
static int	DEFAULT_SOTIMEOUT The default value for the accept operation timeout.
static int	WAIT_FOREVER Passing a value of 0 to the constructor causes any accept operation to wait indefinitely.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ServerSocket() For internal use only
	ServerSocket(int port) Opens a server socket.
	ServerSocket(int port, int timeout) Opens a server socket.
	ServerSocket(int port, int timeout, int backlog, java.lang.String addr) Opens a server socket.
	ServerSocket(int port, int timeout, java.lang.String addr) Opens a server socket.

Method Summary

Modifier and Type	Method and Description
Socket	accept() Listens for a connection to be made to this socket and accepts it, returning a Socket representing the connection established with the client.
void	close() Closes the server socket.
protected void	finalize()
java.lang.String	getHost() Returns the local address of this server socket.
int	getLocalPort() Returns the local TCP port on which this socket is listening, passed in the constructor.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_SOTIMEOUT

public static final int DEFAULT_SOTIMEOUT

The default value for the accept operation timeout.

See Also:

Constant Field Values

DEFAULT_BACKLOG

public static final int DEFAULT_BACKLOG

The default backlog value

See Also:

Constant Field Values

WAIT_FOREVER

public static final int WAIT_FOREVER

Passing a value of 0 to the constructor causes any accept operation to wait indefinitely.

See Also:

Constant Field Values

Constructor Detail

ServerSocket

protected ServerSocket()

For internal use only

ServerSocket

public ServerSocket(int port)
             throws IOException

Opens a server socket. This method establishes a server socket connection at the specified port, with the default timeout for accept operations.

Parameters:

port - the local TCP port to listen for incoming connections

Throws:

IOException

ServerSocket

public ServerSocket(int port,
                    int timeout)
             throws IOException

Opens a server socket. This method establishes a server socket connection at the specified port, with the specified timeout for accept operations.

Parameters:

port - the local TCP port to listen for incoming connections

timeout - the accept operation timeout

Throws:

IOException

ServerSocket

public ServerSocket(int port,
                    int timeout,
                    java.lang.String addr)
             throws IOException

Opens a server socket. This method establishes a server socket connection at the specified port, with the specified timeout for accept operations. The addr argument can be used on a multi-homed host for a ServerSocket that will only accept connect requests to one of its addresses.

Parameters:

port - the local TCP port to listen for incoming connections

timeout - the accept operation timeout

addr - the local address this server will bind to

Throws:

IOException

ServerSocket

public ServerSocket(int port,
                    int timeout,
                    int backlog,
                    java.lang.String addr)
             throws IOException

Opens a server socket. This method establishes a server socket connection at the specified port, with the specified timeout for accept operations. The addr argument can be used on a multi-homed host for a ServerSocket that will only accept connect requests to one of its addresses.

Parameters:

port - the local TCP port to listen for incoming connections

timeout - the accept operation timeout

backlog - the limit of concurrent connections that are accepted.

addr - the local address this server will bind to

Throws:

IOException

Method Detail

getHost

public java.lang.String getHost()

Returns the local address of this server socket.

Returns:

the address to which this socket is bound, or null if the socket is unbound.

getLocalPort

public int getLocalPort()

Returns the local TCP port on which this socket is listening, passed in the constructor.

Returns:

the port number to which this socket is listening.

accept

public Socket accept()
              throws IOException

Listens for a connection to be made to this socket and accepts it, returning a Socket representing the connection established with the client. This method blocks until a connection is made or the operation times out.

Returns:

the client Socket

Throws:

IOException

close

public void close()
           throws IOException

Closes the server socket.

Throws:

IOException

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object