[jcifs] SmbException Supercedes boolean?

Allen, Michael B (RSCH) Michael_B_Allen at ml.com
Tue Oct 30 11:29:33 EST 2001

> -----Original Message-----
> From:	Rob Wygand [SMTP:rob at wygand.com]
> just a boolean return value doesn't do it.  Exceptions do. I've talked 
> before about having some other mechanism (such as an some sort of error 
> handler class), but Mike seemed set on Exceptions.
	There will be no "Error Handler" but there will be an AuthHandler. To clarify
	how the new api will change. Some SmbFile methods will throw the now
	public SmbException. In addition, an AuthHandler interface has been (is
	being) added. Code might take advantage of this like:

	public class MyApp implements AuthHandler {

		public boolean authenticate( AuthInfo ai ) {
			System.out.println( "Authentication for " + ai.domain + "\\" +
	 	                          ai.username + " at " + ai.url + " failed" );

			System.out.print( "Username: " );
			ai.username = in.readLine();
			System.out.print( "Password: " );
			ai.password = in.readLine();
			return ai.username.length() > 0;

		long doSomthing() {
			while( true ) {
				try {
					return file.length();
				} catch( SmbException se ) {
					if( se.errorClass == SmbException.ERRbadshare ) {
						Thread.sleep( 10 * 60 * 1000 );
					} else {
						System.out.println( se.getMessage() );

	This demonstrates several important things. One is that all authentication
	releated exceptions are caught internally and passed in AuthInfo to the
	AuthHandler implementation (in this case it's MyApp). AuthInfo has the
	domain, username, password, target resource, and possibly the
	SmbException. The other is that you can catch and interrogate the
	SmbExceptions. There are literrally several hundred possible error codes
	(not all of which have String messages) so this mechanism will allow users
	to act on this feedback. In the example above this would probably print
	something like:

	$ java -Djcifs.properties=miallen.prp MyApp smb://server/tapemnt/foo.txt
	Authentication for nyrsch\yoyo at smb://server/tapemnt/foo.txt failed.
	Username: miallen
	Password: hello
	The device is not ready.

	Which returns the size of a file unless it's being accessed by another
	process in which case it will sleep for 10 minutes and try again. In the output
	above the SmbException.ERRnotready was not caught; you know this as
	the message you get when you try to access your cdrom with out a disk in it

	Of course if you don't care about Exceptions this code might look like:

	long doSomething() {
		try {
			return file.length();
		} catch( Exception x ) {
		return 0L;


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