The Java® Language Specification, Java SE 7 Edition, Fourth Edition

5.5. Casting Conversion

Casting conversion is applied to the operand of a cast operator (§15.16): the type of the operand expression must be converted to the type explicitly named by the cast operator.

Casting contexts allow the use of one of:

• an identity conversion (§5.1.1)

• a widening primitive conversion (§5.1.2)

• a narrowing primitive conversion (§5.1.3)

• a widening and narrowing primitive conversion (§5.1.4)

• a widening reference conversion (§5.1.5) optionally followed by either an unboxing conversion (§5.1.8) or an unchecked conversion (§5.1.9)

• a narrowing reference conversion (§5.1.6) optionally followed by either an unboxing conversion (§5.1.8) or an unchecked conversion (§5.1.9)

• a boxing conversion (§5.1.7) optionally followed ...