Connection Strategy

Question

i've got a problem with the speed of connecting to AD servers when the server is not available.
normally when i do a search for a user using the search method on the DirContext class and the server is available it normally everything goes smooth.. what i wanted to do was catch a ConnectException just in case the server I am binding to is not available.. I tried a simple bind :
     String server = "<an IP address, but of course it does not exist or is actually down on the network>";
     string strUrl = "ldap://" + server + "<some valid URL>";
     hUserInfo = new HashMap();
     members = new Vector();
     env = new Hashtable(5, 0.75F);
     env.put("java.naming.ldap.version", "3");
     env.put("java.naming.referral", "throw");
     env.put("java.naming.security.authentication", "simple");
     env.put("java.naming.factory.initial", "com.sun.jndi.ldap.LdapCtxFactory");
     env.put("java.naming.provider.url", strUrl);
     env.put("java.naming.security.principal", strPrincipalName);
     env.put("java.naming.security.credentials", strPrincipalCreds);
     try
         ctx = new InitialDirContext(env);
     catch(NamingException ne)
         System.err.println("Error\t: Naming Exception occured");
         ne.printStackTrace();
     catch(Exception e)
         System.err.println("Error\t: General Exception occured");
         e.printStackTrace();
     }just in case it was going to refuse binding to that server but what happened was it accepted the bind even if the address i was passing was not available. it struck me that the only way was to do a directory search on the server that i binded to. my question is, is there a better way to see if the server is available other than doing a directory search on that server. "better" in terms of on how fast it would return the ConnectException or any exception denoting that the server is not available.. hope you guys could help

Answer 1

Now I know why the ConnectException was happening.. it was trying to look for the address but the server connection timed out:
Error     : Naming Exception occured
javax.naming.CommunicationException: <some IP address>:389 [Root exception is java.net.ConnectException: Connection timed out: connect]
     at com.sun.jndi.ldap.Connection.<init>(Unknown Source)
     at com.sun.jndi.ldap.LdapClient.<init>(Unknown Source)
     at com.sun.jndi.ldap.LdapClient.getInstance(Unknown Source)
     at com.sun.jndi.ldap.LdapCtx.connect(Unknown Source)
     at com.sun.jndi.ldap.LdapCtx.<init>(Unknown Source)
     at com.sun.jndi.ldap.LdapCtxFactory.getUsingURL(Unknown Source)
     at com.sun.jndi.ldap.LdapCtxFactory.getUsingURLs(Unknown Source)
     at com.sun.jndi.ldap.LdapCtxFactory.getLdapCtxInstance(Unknown Source)
     at com.sun.jndi.ldap.LdapCtxFactory.getInitialContext(Unknown Source)
     at javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
     at javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
     at javax.naming.InitialContext.init(Unknown Source)
     at javax.naming.InitialContext.<init>(Unknown Source)
     at javax.naming.directory.InitialDirContext.<init>(Unknown Source)
     at com.pwdReset.unlock.ADUnlock.<init>(ADUnlock.java:98)
     at com.pwdReset.unlock.TestADUnlock.main(TestADUnlock.java:30)
Caused by: java.net.ConnectException: Connection timed out: connect
     at java.net.PlainSocketImpl.socketConnect(Native Method)
     at java.net.PlainSocketImpl.doConnect(Unknown Source)
     at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
     at java.net.PlainSocketImpl.connect(Unknown Source)
     at java.net.Socket.connect(Unknown Source)
     at java.net.Socket.connect(Unknown Source)
     at java.net.Socket.<init>(Unknown Source)
     at java.net.Socket.<init>(Unknown Source)
     at com.sun.jndi.ldap.Connection.createSocket(Unknown Source)
     ... 16 moreso i guess the right exception I am looking for is not probably ConnectException
or ConnectException is the right one but I'm trying to find it the wrong way by letting it timeout...