AP Computer Science: Designing Classes – The Station Class

A gas station needs to keep track of the current number of gallons on hand at each pump. The station has at least one pump. Pumps are numbered 1-n with n being the total number of pumps at the station. The handling of this data will be done by the Station class, as described below.

Data Members

private int numPumps; // number of pumps at the station

private double[] gallons; // number of gallons left in each pump

Constructor

public Station(int numP, double numG)

// Creates an array of size numP and sets all pumps to numG gallons.

Accessor Methods

public int getNumPumps()

// Returns the number of pumps in the station.

public double getGallonsLeft(int n)

// Returns the number of gallons left at pump n.

public double getTotalGallonsLeft()

// Returns the total number of gallons left for the entire station.

Modifier Methods

public void pumpGas(int n, double gal)

// Deducts gal gallons from pump number n. If there are not enough

// gallons left, the number of gallons at that pump becomes 0.0

Additional Method

public void printReport()

// Prints a report listing the number of gallons remaining at each

// pump as well as the total number of gallons left in the station.

// See the example report below.

Pump 1:  134.4

Pump 2:  158.6

Pump 3:  164.3

Total:   457.3

Use the file StationTest.java to test out your class. The results of the printReport() at the end of the program should match the above example. The file will be put in the Period 4 folder.