A. j_user and j_idB. j_id and j_passwordC. j_users and ……

单项选择题What else must the developer do to ensure that the intended security goal is achieved（）？

A. Create a user called vip in the security realm
B. Define a group within the security realm and call it vip
C. Define a security-role named vip in the development descriptor
D. Declare a security-role-ref for vip in the deployment descriptor

多项选择题Whichtwoauthenticationmechanismsprovideweakerprotectionthanothermechanisms？（）

A. HTTP Basic Authentication
B. Form Based Authentication
C. HTTP Digest Authentication
D. HTTPS Client Authentication

多项选择题Whichthreeareguaranteedtobevalidfortheelementofawebapplicationdeploymentdescriptor？（）

A. FORM
B. DIGEST
C. NORMAL
D. ENCRYPTED
E. CLIENT-CERT

多项选择题Which the three EL expressions， inserted at line 15， are valid and evaluate to  3 ？ （）

A. ${vals.2 }
B. ${vals ["2"]}
C. ${vals.index }
D. ${vals[index]}
E. ${vals} [index]
F. ${vals.（vals.index）}
G. ${vals[vals[index-1]]}

单项选择题GivenaJSPerrorpage，whichimplicitobjectreferstotheuncaughtThrowablethatresultedinthepagebeinginvoked？（）

A. Error
B. Exception
C. Throwable
D. Request error
E. Request exception