The Java Language Specification, Third Edition

EXPRESSIONS Anonymous Class Declarations 15.9.5
The value of a class instance creation expression is a reference to the newly
created object of the specified class. Every time the expression is evaluated, a
fresh object is created.
15.9.5 Anonymous Class Declarations
An anonymous class declaration is automatically derived from a class instance
creation expression by the compiler.
An anonymous class is never abstract (§8.1.1.1). An anonymous class is
always an inner class (§8.1.3); it is never static (§8.1.1, §8.5.2). An anonymous
class is always implicitly final (§8.1.1.2).
15.9.5.1 Anonymous Constructors
An anonymous class cannot have an explicitly declared constructor. Instead, the
compiler must automatically provide an anonymous constructor for the anonymous
class. The form of the anonymous constructor of an anonymous class C with
direct superclass S is as follows:
• If S is not an inner class, or if S is a local class that occurs in a static context,
then the anonymous constructor has one formal parameter for each actual
argument to the class instance creation expression in which C is declared. The
actual arguments to the class instance creation expression are used to determine
a constructor cs of S, using the same rules as for method invocations
(§15.12). The type of each formal parameter of the anonymous constructor
must be identical to the corresponding formal parameter of cs.
The body of the constructor consists of an explicit constructor invocation
(§8.8.7.1) of the form super(...), where the actual arguments are the formal
parameters of the constructor, in the order they were declared.
• Otherwise, the first formal parameter of the constructor of C represents the
value of the immediately enclosing instance of i with respect to S. The type of
this parameter is the class type that immediately encloses the declaration of S.
The constructor has an additional formal parameter for each actual argument
to the class instance creation expression that declared the anonymous class.
The nth formal parameter e corresponds to the n –
1 st actual argument. The
actual arguments to the class instance creation expression are used to determine
a constructor cs of S, using the same rules as for method invocations
(§15.12). The type of each formal parameter of the anonymous constructor
must be identical to the corresponding formal parameter of cs. The body of
the constructor consists of an explicit constructor invocation (§8.8.7.1) of the
form o.super(...), where o is the first formal parameter of the constructor, and
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