About Beans

CDI redefines the concept of a bean beyond its use in other Java technologies, such as the JavaBeans^TM and Enterprise JavaBeans^TM (EJB^TM) technologies. In CDI, a bean is a source of contextual objects that defines application state and/or logic. A Java EE component is a bean if the lifecycle of its instances may be managed by the container according to the lifecycle context model defined in the CDI specification.

More specifically, a bean has the following attributes:

• A (nonempty) set of bean types

• A (nonempty) set of qualifiers (see Using Qualifiers)

• A scope (see Using Scopes)

• Optionally, a bean EL name (see Giving Beans EL Names)

• A set of interceptor bindings

• A bean implementation

A bean type defines a client-visible type of the bean. Almost any Java type may be a bean type of a bean:

• A bean type may be an interface, a concrete class or an abstract class, and may be declared final or have final methods.

• A bean type may be a parameterized type with actual type parameters and type variables.

• A bean type may be an array type. Two array types are considered identical only if the element type is identical.

• A bean type may be a primitive type. Primitive types are considered to be identical to their corresponding wrapper types in java.lang.

• A bean type may be a raw type.