13.3.3. Subject and Principal classes

download PDF
To authorize access to resources, applications must first authenticate the request's source. The JAAS framework defines the term subject to represent a request's source. The Subject class is the central class in JAAS. A Subject represents information for a single entity, such as a person or service. It encompasses the entity's principals, public credentials, and private credentials. The JAAS API uses the existing Java 2 interface to represent a principal, which is essentially a typed name.
During the authentication process, a subject is populated with associated identities, or principals. A subject may have many principals. For example, a person may have a name principal (John Doe), a social security number principal (123-45-6789), and a user name principal (johnd), all of which help distinguish the subject from other subjects. To retrieve the principals associated with a subject, two methods are available:
public Set getPrincipals() {...}
public Set getPrincipals(Class c) {...}
getPrincipals() returns all principals contained in the subject. getPrincipals(Class c) returns only those principals that are instances of class c or one of its subclasses. An empty set is returned if the subject has no matching principals.
Note that the interface is a sub-interface of, so an instance in the principals set may represent a logical grouping of other principals or groups of principals.
Red Hat logoGithubRedditYoutubeTwitter


Try, buy, & sell


About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.