JNDI/LDAP - 为广播通知注册一个监听器

import java.util.Hashtable;   
  
import javax.naming.Context;   
import javax.naming.InitialContext;   
import javax.naming.NamingException;   
import javax.naming.event.EventContext;   
import javax.naming.event.NamingExceptionEvent;   
import javax.naming.event.NamingListener;   
import javax.naming.ldap.UnsolicitedNotificationEvent;   
import javax.naming.ldap.UnsolicitedNotificationListener;   
  
/**  
* Demonstrates how to register a listener for Unsolicited Notifications. In  
* order for the listener to receive a notification, you must prod the directory  
* server to send an Unsolicited Notification. The procedure for doing so is  
* directory-dependent.  
*   
* usage: java RegUnsol  
*/  
class RegUnsol {   
  public static void main(String[] args) {   
  
    // Set up environment for creating initial context   
    Hashtable<String, Object> env = new Hashtable<String, Object>(11);   
    env   
        .put(Context.INITIAL_CONTEXT_FACTORY,   
            "com.sun.jndi.ldap.LdapCtxFactory");   
    env.put(Context.PROVIDER_URL, "ldap://localhost:389/o=JNDItutorial");   
  
    try {   
      // Get event context for registering listener   
      EventContext ctx = (EventContext) (new InitialContext(env)   
          .lookup("ou=People"));   
  
      // Create listener   
      NamingListener listener = new UnsolListener();   
  
      // Register listener with context (all targets equivalent)   
      ctx.addNamingListener("", EventContext.ONELEVEL_SCOPE, listener);   
  
      // Wait 1 minutes for listener to receive events   
      try {   
        Thread.sleep(60000);   
      } catch (InterruptedException e) {   
        System.out.println("sleep interrupted");   
      }   
  
      // Not strictly necessary if we're going to close context anyhow   
      ctx.removeNamingListener(listener);   
  
      // Close context when we're done   
      ctx.close();   
  
    } catch (NamingException e) {   
      e.printStackTrace();   
    }   
  }   
  
  /**  
   * A sample UnsolicitedNotificationListener.  
   */  
  static class UnsolListener implements UnsolicitedNotificationListener {   
    public void notificationReceived(UnsolicitedNotificationEvent evt) {   
      System.out.println("received: " + evt);   
    }   
  
    public void namingExceptionThrown(NamingExceptionEvent evt) {   
      System.out.println(">>> UnsolListener got an exception");   
      evt.getException().printStackTrace();   
    }   
  }   
}