Java Reference
In-Depth Information
Example 5•9: Server.java (continued)
* connection on a port, passes input and output streams to a specified Service
* object which provides the actual service. It can limit the number of
* concurrent connections, and logs activity to a specified stream.
**/
public class Server {
/**
* A main() method for running the server as a standalone program. The
* command-line arguments to the program should be pairs of servicenames
* and port numbers. For each pair, the program will dynamically load the
* named Service class, instantiate it, and tell the server to provide
* that Service on the specified port. The special -control argument
* should be followed by a password and port, and will start special
* server control service running on the specified port, protected by the
* specified password.
**/
public static void main(String[] args) {
try {
if (args.length < 2) // Check number of arguments
throw new IllegalArgumentException("Must specify a service");
// Create a Server object that uses standard out as its log and
// has a limit of ten concurrent connections at once.
Server s = new Server(System.out, 10);
// Parse the argument list
int i = 0;
while(i < args.length) {
if (args[i].equals("-control")) { // Handle the -control arg
i++;
String password = args[i++];
int port = Integer.parseInt(args[i++]);
// add control service
s.addService(new Control(s, password), port);
}
else {
// Otherwise start a named service on the specified port.
// Dynamically load and instantiate a Service class
String serviceName = args[i++];
Class serviceClass = Class.forName(serviceName);
Service service = (Service)serviceClass.newInstance();
int port = Integer.parseInt(args[i++]);
s.addService(service, port);
}
}
}
catch (Exception e) { // Display a message if anything goes wrong
System.err.println("Server: " + e);
System.err.println("Usage: java Server " +
"[-control <password> <port>] " +
"[<servicename> <port> ... ]");
System.exit(1);
}
}
// This is the state for the server
Map services;
// Hashtable mapping ports to Listeners
Set connections;
// The set of current connections
int maxConnections;
// The concurrent connection limit
