PACKAGE

To create a package is quite easy: simply include a package command as the first statement in java source file. Any classes declared within that file will belong to the specified package. The package statement defines a name space in which classes are stored.If you omit the package statement, the class names are put into the default package. This is the general form of the package statement:         
                                                                    package pkg;
Here, pkg is the package name of the package. You can create a hierarchy of packages. To do so, simply separate each package name from the one above it by use of a period.The general form of a multileveled package.
                                                            package pkg1.pkg2.pkg3;
A package hierarchy must be reflected in the file system of your java Development system.
A Short Package Example:
package Mypackage; class Balance{ String name; double balance; Balance(String n, double b){ name=n; balance=b; } void run(){ if(balance<0){ System.out.println("------>"); System.out.println(name +" : $"+balance);} } public static void main(String []arg){ Balance bl[]=new Balance[3]; bl[0]=new Balance("manoj", 1111111.777); bl[1]=new Balance("kumar", 19999111.777); bl[2]=new Balance("m. k. ", -888888.877); for(int i=0; i<3; i++){ bl[i].run(); } } }