问题
I've been a little puzzled with this as I have not seen many examples that gave me the complete picture. The best explanation I found so far is this.
By defining a security role in web.xml such as "admin" for example, and having my login form with all the necessary fields (i.e j_security_check as action, and fields j_username, j_password), how/where does the actual authentication occur?
I plan to use a custom authentication using username/passwords (hashes) stored in the database. When the user submits the form, how do I make the Java EE Web Container invoke my sevlet/bean method do perform the actual authentication? I didn't notice any place to add a hook to my code in web.xml which would do the actual authentication.
回答1:
By defining a security role in web.xml such as "admin" for example, and having my login form with all the necessary fields (i.e j_security_check as action, and fields j_username, j_password), how/where does the actual authentication occur?
In the servlet implementation, the servletcontainer. In Tomcat for example, it's done by the AuthenticatorBase class (source code here).
I plan to use a custom authentication using username/passwords (hashes) stored in the database. When the user submits the form, how do I make the Java EE Web Container invoke my sevlet/bean method do perform the actual authentication? I didn't notice any place to add a hook to my code in web.xml which would do the actual authentication.
If you'd like to keep using container managed authentication, but instead want to check the login against a database, then you need to configure the so-called "realm" accordingly. It's unclear which servletcontainer you're using, but in for example Tomcat, the documentation is available here: Tomcat 6.0 Realm HOW-TO.
If you really want to have your own homegrown authentication system invoked instead, then you need to drop the container managed security and homegrow it further. Which is not recommended.
回答2:
The actual authentication is doing via either two ways:
- Via a Server Proprietary way, e.g. the *LoginModules in JBoss, or the Tomcat one BalusC mentioned. These are different for each Server.
- Via JASPIC, which was introduced in Java EE 6.
JASPIC pretty much has standardized the proprietary methods, but it's a fairly low-level API and unfortunately only available for full profile Java EE 6 and 7 implementations.
See Implementing container authentication in Java EE with JASPIC for more details.
来源：https://stackoverflow.com/questions/4024192/jsp-login-with-declarative-security-how-does-the-actual-authentication-happen