package com.oreilly.jent.jndi;
/**
* In general, you may use the code in this book in your programs and
* documentation. You do not need to contact us for permission unless
* you're reproducing a significant portion of the code. For example,
* writing a program that uses several chunks of code from this book does
* not require permission. Selling or distributing a CD-ROM of examples
* from O'Reilly books does require permission. Answering a question by
* citing this book and quoting example code does not require permission.
* Incorporating a significant amount of example code from this book into
* your product's documentation does require permission.
*
* We appreciate, but do not require, attribution. An attribution usually
* includes the title, author, publisher, and ISBN. For example:
*
* "Java Enterprise in a Nutshell, Third Edition,
* by Jim Farley and William Crawford
* with Prakash Malani, John G. Norman, and Justin Gehtland.
* Copyright 2006 O'Reilly Media, Inc., 0-596-10142-2."
*
* If you feel your use of code examples falls outside fair use or the
* permission given above, feel free to contact us at
* permissions@oreilly.com.
*/
/**
* listen: Command to listen for events in a JNDI context.
*/
import java.util.Vector;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.event.EventContext;
import javax.naming.event.EventDirContext;
import javax.naming.event.NamingListener;
class listen implements Command {
public void execute(Context c, Vector v) throws CommandException {
if (NamingShell.getCurrentContext() == null)
throw new CommandException(new Exception(), "No current context");
else if (v.isEmpty())
throw new CommandException(new Exception(), "No target specified");
String name = (String)v.firstElement();
String filter = null;
if (v.size() > 1) {
filter = (String)v.elementAt(1);
}
try {
// Cast context to an event context
EventContext evCtx = (EventContext)c;
// Create our listener
NamingListener listener = new AnyChangeLogger();
// If no filter specified, just register a listener using EventContext
if (filter == null) {
evCtx.addNamingListener(name, EventContext.OBJECT_SCOPE, listener);
}
// If we have a filter, use the EventDirContext to specify the target
else {
EventDirContext evDirCtx = (EventDirContext)c;
evDirCtx.addNamingListener(name, filter, null, listener);
}
System.out.println("Registered listener for " + name +
(filter != null ? (" and filter " + filter) : ""));
}
catch (ClassCastException cce) {
cce.printStackTrace();
throw new CommandException(cce,
"The current context does not support event notification.");
}
catch (NamingException e) {
throw new CommandException(e, "The search for " + filter + " failed");
}
}
public void help() { System.out.println("Usage: listen name [filter]"); }
}
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