j2ee turorial6的问题

按照教程的方法使用ant在glassfish服务器上面部署应用时，碰到了如下问题：
： ant deploy
check:
tools:
-pre-deploy:
deploy:
       [exec] Command deploy failed.
       [exec] Authentication failed for user: null
       [exec] (Usually, this means invalid user name and /or password)
BUILD FAILED
/home/daniel /glassfish3/glassfish/docs/javaee-turorial/examples/bp-project/app-server-ant.xml:434:exec returned: 1有哪位大神知道为什么有问题么？