7.4.3

Scope and Hiding of a Package Name

PACKAGES

about situations in which a named package is used by more than one unnamed

package. It is specifically not required indeed, it is strongly discouraged for an

implementation to support use of a named package by more than one unnamed

package by maintaining multiple compiled versions of the named package.

7.4.3   Scope and Hiding of a Package Name

Which top level package names are in scope ( 6.3,  6.5) is determined by con 

ventions of the host system.

Package names never hide other names.

7.4.4   Access to Members of a Package

Whether access to members of a package is allowed is determined by the host sys 

tem. The package

java

 should always be accessible, and its standard subpackages

lang

,

io

, and

util

 should always be accessible.

It is strongly recommended that the protections of a file system or database

used to store Java programs be set to make all compilation units of a package

available whenever any of the compilation units is available.

7.5   Import Declarations

An

import declaration

 allows a type declared in another package to be referred to

by a simple name ( 6.2) that consists of a single identifier. Without the use of an

appropriate

import

 declaration, the only way to refer to a type declared in another

package is to use its fully qualified name ( 6.7).

ImportDeclaration:

SingleTypeImportDeclaration

TypeImportOnDemandDeclaration

A single type import declaration ( 7.5.1) imports a single type, by mention 

ing its fully qualified name. A type import on demand declaration ( 7.5.2)

imports all the

public

 types of a named package as needed.

An

import

 declaration makes types available by their simple names only

within the compilation unit that actually contains the

import

 declaration. The

scope of the name(s) it introduces specifically does not include the

package

 state 

ment, other

import

 statements in the current compilation unit, or other compila 

tion units in the same package. Please see  7.5.4 for an illustrative example.

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