- if (args.length == 0) {
- System.err.println("usage: java " + SpnegoAuthScheme.class.getName() + " <url>");
+ String principal = System.getProperty("javax.security.auth.login.name");
+ if (args.length == 0 || principal == null) {
+ System.err.println("usage: java -Djavax.security.auth.login.name=<principal@REALM> "
+ + SpnegoAuthScheme.class.getName() + " <url>");