Sun Microsystems V2.0 manual Client end, Server end

where serverAddr is the 64bit IEEE Address of the radio of the server, and portNo is a port number in the range 0 to 255 that identifies this particular connection. Note that 0 is not a valid IEEE address in this implementation. The port number must match the port number used by the server.

Data is sent between the client and server in datagrams, of type Datagram. To get an empty datagram you must ask the connection for one:

Datagram dg = conn.newDatagram(conn.getMaximumLength());

Datagrams support stream-like operations, acting as both a DataInputStream and a DataOutputStream. The amount of data that may be written into a datagram is limited by its length. When using stream operations to read data the datagram will throw an EOFException if an attempt is made to read beyond the valid data.

A datagram is sent by asking the connection to send it:

conn.send(dg);

A datagram is received by asking the connection to fill in one supplied by the application:

conn.receive(dg);

Here's a complete example:

Client end

RadiogramConnection conn = (RadiogramConnection)Connector.open("radiogram://0014.4F01.0000.0006:10");

Datagram dg = conn.newDatagram(conn.getMaximumLength()); try {

dg.writeUTF("Hello up there"); conn.send(dg); conn.receive(dg);

System.out.println ("Received: " + dg.readUTF()); } catch (NoRouteException e) {

System.out.println ("No route to 0014.4F01.0000.0006");

}finally { conn.close();

}

Server end

RadiogramConnection conn = (RadiogramConnection) Connector.open("radiogram://:10"); Datagram dg = conn.newDatagram(conn.getMaximumLength());

Datagram dgreply = conn.newDatagram(conn.getMaximumLength()); try {

conn.receive(dg);

String question = dg.readUTF(); dgreply.reset(); // reset stream pointer dgreply.setAddress(dg); // copy reply address from input if (question.equals("Hello up there")) {

dgreply.writeUTF("Hello down there");

}else { dgreply.writeUTF("What???");

}

conn.send(dgreply);

} catch (NoRouteException e) {

System.out.println ("No route to " + dgreply.getAddress()); } finally {

conn.close();

}

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