Packages are containers for classes that are used to keepthe class name space compartmentalized.

General form of Package statement:

package pkg;

A package hierarchy must be reflected in the file system of your java development system.

Example:

package Java.awt.image;

needs to be stored in java/awt/image or java\awt\image on UNIX or Windows file system respectively.

CLASSPATH environment variable

test.Packtest.java

if you are working on source code in directory called C:\myjava, then set your CLASSPATH to

.;C:\myjava;C:\java\classes

import pkg1[.pkg2].(classname|*);

import java.util.Date;

import java.util.*;

• * form may increase compilation time-especially if you import several large packages. For this reason it is good idea to explicitly name th class that you want to use rather than importing the whole packages.
• * has no effect on the run-time performance or size of your class.

import java.util.*;

class MyDate extends Date{

}

class MyDate extends java.util.Date{

}

java.lang is implicitly imported. Equivalent to

import java.lang.*;