how to test/run a simple inheritance hierarchy in Eclipse

[David Schwartz]

wanted to ask where i can find simple instructions on how to run a simple inheritance (see code below) in Eclipse?


thank you

  import java.text.DecimalFormat;
import javax.swing.JOptionPane;

public class PayrollSystemTest {

   public static void main( String[] args ) 
   {
      DecimalFormat twoDigits = new DecimalFormat( "0.00" );

      // create Employee array
      Employee employees[] = new Employee[ 4 ];

      // initialize array with Employees
      employees[ 0 ] = new SalariedEmployee( "John", "Smith", 
         "111-11-1111", 800.00 );
      employees[ 1 ] = new CommissionEmployee( "Sue", "Jones", 
         "222-22-2222", 10000, .06 );
      employees[ 2 ] = new BasePlusCommissionEmployee( "Bob", "Lewis", 
         "333-33-3333", 5000, .04, 300 );
      employees[ 3 ] = new HourlyEmployee( "Karen", "Price", 
         "444-44-4444", 16.75, 40 );

      String output = "";

      // generically process each element in array employees
      for ( int i = 0; i < employees.length; i++ ) {
         output += employees[ i ].toString();

         // determine whether element is a BasePlusCommissionEmployee
         if ( employees[ i ] instanceof BasePlusCommissionEmployee ) {

            // downcast Employee reference to 
            // BasePlusCommissionEmployee reference
            BasePlusCommissionEmployee currentEmployee = 
               ( BasePlusCommissionEmployee ) employees[ i ];

            double oldBaseSalary = currentEmployee.getBaseSalary();
            output += "\nold base salary: $" + oldBaseSalary;      
            
            currentEmployee.setBaseSalary( 1.10 * oldBaseSalary );
            output += "\nnew base salary with 10% increase is: $" +
               currentEmployee.getBaseSalary();

         } // end if

         output += "\nearned $" + employees[ i ].earnings() + "\n";

      } // end for

      // get type name of each object in employees array
      for ( int j = 0; j < employees.length; j++ )
         output += "\nEmployee " + j + " is a " +
            employees[ j ].getClass().getName(); 

      JOptionPane.showMessageDialog( null, output );  // display output
      System.exit( 0 );

   } // end main

} // end class PayrollSystemTest  

=============

  public class BasePlusCommissionEmployee extends CommissionEmployee {
   private double baseSalary;  // base salary per week

   // constructor
   public BasePlusCommissionEmployee( String first, String last, 
      String socialSecurityNumber, double grossSalesAmount,
      double rate, double baseSalaryAmount )
   {
      super( first, last, socialSecurityNumber, grossSalesAmount, rate );
      setBaseSalary( baseSalaryAmount );
   } 

   // set base-salaried commission employee's base salary
   public void setBaseSalary( double salary )
   {
      baseSalary = salary < 0.0 ? 0.0 : salary;
   } 

   // return base-salaried commission employee's base salary
   public double getBaseSalary()
   {
      return baseSalary;
   } 

   // calculate base-salaried commission employee's earnings;
   // override method earnings in CommissionEmployee
   public double earnings()
   {
      return getBaseSalary() + super.earnings();
   } 

   // return String representation of BasePlusCommissionEmployee
   public String toString()
   {
      return "\nbase-salaried commission employee: " +
         super.getFirstName() + " " + super.getLastName() +
         "\nsocial security number: " + super.getSocialSecurityNumber();
   } 
   
} // end class BasePlusCommissionEmployee  

=============

   public class CommissionEmployee extends Employee {
   private double grossSales;      // gross weekly sales
   private double commissionRate;  // commission percentage

   // constructor
   public CommissionEmployee( String first, String last, 
      String socialSecurityNumber, 
      double grossWeeklySales, double percent )
   {
      super( first, last, socialSecurityNumber );
      setGrossSales( grossWeeklySales );
      setCommissionRate( percent );
   } 

   // set commission employee's rate
   public void setCommissionRate( double rate )
   {
      commissionRate = ( rate > 0.0 && rate < 1.0 ) ? rate : 0.0;
   } 

   // return commission employee's rate
   public double getCommissionRate()
   {
      return commissionRate;
   } 

   // set commission employee's weekly base salary
   public void setGrossSales( double sales )
   {
      grossSales = sales < 0.0 ? 0.0 : sales;
   } 

   // return commission employee's gross sales amount
   public double getGrossSales()
   {
      return grossSales;
   } 

   // calculate commission employee's pay;
   // override abstract method earnings in Employee
   public double earnings()
   {
      return getCommissionRate() * getGrossSales();
   } 

   // return String representation of CommissionEmployee object
   public String toString()
   {
      return "\ncommission employee: " + super.toString();
   } 
   
} // end class CommissionEmployee 

[Campbell Ritchie]

Why not run it from the command-line? You are better off not using an IDE at this stage, if possible.

I have found an Eclipse Tutorial; that might help.
When you open the new class wizard in Eclipse, it asks for the name of the class, and also it superclass; if you put "Employee" in the superclass box, it will automaticaly add extends Employee to your source code.

I think this thread might sit better on our IDEs forum, so shall move it there.

[David Schwartz]

got it thank you

[Campbell Ritchie]

You're welcome