The Java Language Specification, Third Edition

TYPES, VALUES, AND VARIABLES Type Variables 4.4
The string concatenation operator + (§15.18.1) implicitly creates a new
String object when the result is not a compile-time constant (§15.28).
4.3.4 When Reference Types Are the Same
Two reference types are the same compile-time type if they have the same binary
name (§13.1) and their type parameters, if any, are the same, applying this definition
recursively. When two reference types are the same, they are sometimes said
to be the same class or the same interface.
At run time, several reference types with the same binary name may be loaded
simultaneously by different class loaders. These types may or may not represent
the same type declaration. Even if two such types do represent the same type declaration,
they are considered distinct.
Two reference types are the same run-time type if:
• They are both class or both interface types, are defined by the same class
loader, and have the same binary name (§13.1), in which case they are sometimes
said to be the same run-time class or the same run-time interface.
• They are both array types, and their component types are the same run-time
type(§10).
4.4 Type Variables
A type variable (§4.4) is an unqualified identifier. Type variables are introduced
by generic class declarations (§8.1.2) generic interface declarations (§9.1.2)
generic method declarations (§8.4.4) and by generic constructor declarations
(§8.8.4).
TypeParameter:
TypeVariable TypeBoundopt TypeBound:
DRAFT
extends ClassOrInterfaceType AdditionalBoundList opt
AdditionalBoundList:
AdditionalBound AdditionalBoundList
AdditionalBound
AdditionalBound:
& InterfaceType
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