7.4

Package Declarations

PACKAGES

CompilationUnit:

PackageDeclaration

opt

ImportDeclarations

opt

TypeDeclarations

opt

ImportDeclarations:

ImportDeclaration

ImportDeclarations ImportDeclaration

TypeDeclarations:

TypeDeclaration

TypeDeclarations TypeDeclaration

Types declared in different compilation units can depend on each other, circularly.

A Java compiler must arrange to compile all such types at the same time.

A

compilation unit

 consists of three parts, each of which is optional:

A

package

 declaration ( 7.4), giving the fully qualified name ( 6.7) of the

package to which the compilation unit belongs

import

 declarations ( 7.5) that allow types from other packages to be

referred to using their simple names

Type declarations ( 7.6) of class and interface types

Every compilation unit automatically and implicitly imports every

public

type name declared in the predefined package

java.lang

, so that the names of all

those types are available as simple names, as described in  7.5.3.

7.4   Package Declarations

A package declaration appears within a compilation unit to indicate the package

to which the compilation unit belongs. A compilation unit that has no package

declaration is part of an unnamed package.

7.4.1   Named Packages

A

package declaration

 in a compilation unit specifies the name ( 6.2) of the pack 

age to which the compilation unit belongs.

PackageDeclaration:

package

PackageName

 ;

The package name mentioned in a package declaration must be the fully qualified

name ( 6.7) of the package.

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