Java Platform, Enterprise Edition (Java EE) 8 The Java EE Tutorial |
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CDI redefines the concept of a bean beyond its use in other Java technologies, such as the JavaBeans and Enterprise JavaBeans (EJB) technologies. In CDI, a bean is a source of contextual objects that define application state 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 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.
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