package nameserver;
import java.rmi.RMISecurityManager;
import net.jini.discovery.LookupDiscovery;
import net.jini.core.lookup.ServiceTemplate;
import net.jini.discovery.LookupDiscoveryManager;
import net.jini.lookup.ServiceDiscoveryManager;
import net.jini.lookup.LookupCache;
import net.jini.core.lookup.ServiceItem;
import net.jini.lease.LeaseRenewalManager;
import net.jini.lookup.ServiceItemFilter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.MalformedURLException;
import java.io.*;
/**
* NameServer.java
*
*
* Created: Sun Mar 5 2000
*
* @author Jan Newmarch
* @version 1.0
*/
public class NameServer {
private static final long WAITFOR = 100000L;
private static final int PORT = 8000;
private static final int MAXMATCHES = Integer.MAX_VALUE;
private LookupCache cache = null;
private String url;
public static void main(String argv[]) {
new NameServer();
}
public NameServer() {
ServiceDiscoveryManager clientMgr = null;
System.setSecurityManager(new RMISecurityManager());
try {
LookupDiscoveryManager mgr =
new LookupDiscoveryManager(LookupDiscovery.ALL_GROUPS,
null /* unicast locators */,
null /* DiscoveryListener */);
clientMgr = new ServiceDiscoveryManager(mgr,
new LeaseRenewalManager());
} catch(Exception e) {
e.printStackTrace();
System.exit(1);
}
try {
cache = clientMgr.createLookupCache(null, /* wildcard template */
null, /* no filter */
null /* no listener */);
} catch(Exception e) {
e.printStackTrace();
System.exit(1);
}
System.out.println("entering server loop");
/* a really simple server loop
*/
try {
ServerSocket listener = new ServerSocket(PORT);
while (true) {
Socket connection = listener.accept();
System.out.println("opened connection");
BufferedReader in = new BufferedReader(
new InputStreamReader(
connection.getInputStream()));
PrintStream out = new PrintStream(connection.getOutputStream());
String line = in.readLine();
// line expected to be in form "GET url HTTP/1.1"
int start = line.indexOf('/') + 1;
int end = line.indexOf(' ', start);
if (start == 0 || end == -1) {
throw new MalformedURLException();
}
url = line.substring(start, end);
System.out.println("url is \"" + url + "\"");
if (url.equals("")) {
listDir(out);
} else {
sendObject(out);
}
out.close();
}
} catch(Exception e) {
// return error message
}
}
protected void listDir(PrintStream out) throws IOException {
out.print("HTTP/1.1 200 \r\n");
out.print("Content-Type: text/html\r\n\r\n");
out.print(" Services
\r\n");
out.print("\r\n");
ServiceItem[] items = cache.lookup(null, MAXMATCHES);
for (int n = 0; n < items.length; n++) {
Object service = items[n].service;
// Find all the interfaces this implements and list them
// ignore ones like Remote and Serializable.
// For now, just print the classes :-(
out.print("- " + service.getClass().toString());
out.print("
\r\n");
}
out.print("
\r\n\r\n");
}
protected void sendObject(PrintStream out) throws IOException {
Class cls = null;
try {
cls = Class.forName(url);
} catch(Exception e) {
// can't find the interface object for this name
out.print("HTTP/1.1 404 " + url + " interface not found\r\n\r\n");
return;
}
ServiceItemFilter filter = new Filter(cls);
ServiceItem item = cache.lookup(filter);
if (item == null) {
// can't find an implementation of this interface
out.print("HTTP/1.1 404 " + url + " service not found\r\n\r\n");
return;
}
// write the service item to a byte array so we can find out
// how big it is
ByteArrayOutputStream ostream = new ByteArrayOutputStream();
ObjectOutputStream p = new ObjectOutputStream(ostream);
p.writeObject(item);
byte[] bytes = ostream.toByteArray();
// Prepare HTTP header
out.print("HTTP/1.1 200 \r\n");
out.print("Content-Length: " + bytes.length +"\r\n");
out.print("Content-Type: application/x-jini\r\n\r\n");
System.out.println("Content-length: " + bytes.length);
// now write the object to the output stream
out.write(bytes);
}
class Filter implements ServiceItemFilter {
private Class cls;
public Filter(Class cls) {
this.cls = cls;
}
public boolean check(ServiceItem item) {
if (cls.isInstance(item.service)) {
return true;
} else {
return false;
}
}
}
} // NameServer