Class GetPlanFactory

$\{$

$//$ use getPlan method to get object og tupe plan

public Plan getPlan$($string planType$)$

$\{$

if $($planType $==$ null$)$

$\{$

return null;

$\}$

if$($planType$.$equalsIgnoreCase$("$DOMESTICPLANT$))$

$\{$

return new DomesticPlan$()$;

$\}$

else if$($planType$.$equalsIgnoreCase$($COMMERCIALPLANT$))$

$\{$

return new CommercialPlan$()$;

$\}$

else if$($planType$.$equalsIgnoreCase$($INSTITUTIONALPLAN$))$

$\{$

return new InstitutionalPlan$()$;

$\}$

retum null;

$\}$

$\}$

Create the following three Concrete classes that extends Plan abstract class.

a$)$ DomesticPlan, InstitutionalPlan, CommercialPlan

b$)$ Each plan returns the rate at which electricity bill can be paid. Such as$,$ for domestioplas is $3\mathrm{.}5,$ for InstitutionalPlan is $5\mathrm{.}5$ and CommercialPlan is $5\mathrm{.}5$

Answer:

class DomesticPlan

$\{$