I'm really confused about Java classes and driver programs. What is the syntax of the code for a driver program and what should and should not be inside it? For the driver program we need perhaps to have a main program inside it but what about the Java class, don't we need to have any?
Do I need to have this for both the Java class and the driver program or only in the driver:
public static void main(String[] args) {
}
As referenced from here:
A "Driver class" is often just the class that contains a main. In a real project, you may often have numerous "Driver classes" for testing and whatnot, or you can build a main into any of your objects and select the runnable class through your IDE, or by simply specifying "java classname."
Example:
This is not a driver class since it doesn't contain any main method. In this case, it has the method hello:
public class HelloWorld {
public void hello() {
System.out.println("Hello, world!");
}
}
Versus this one - which is a driver class since it contains a main method, and is the class that runs HelloWorld:
public class HelloWorldDriver {
public static void main(String[] args) {
HelloWorld sayhello = new HelloWorld();
sayhello.hello();
}
}
Hence the name "driver class" - as the class HelloWorldDriver "drives" or rather, controls the instantiation and usage of the class HelloWorld.
import java.util.ArrayList;
import java.util.Scanner;
public class Driver {
private static ArrayList<Dog> dogList = new ArrayList<Dog>();
// Instance variables (if needed)
private static ArrayList<Monkey> monkeyList = new ArrayList<Monkey>();
public static void main(String[] args) {
String userInput;
initializeDogList();
initializeMonkeyList();
displayMenu();
Scanner scanner = new Scanner(System.in);
userInput = scanner.next().toUpperCase();
while (userInput != "Q") {
if ((userInput != "1") && (userInput != "2") && (userInput != "3")
&& (userInput != "4") && (userInput != "5") && (userInput != "6")) {
System.out.println("Invalid Entry");
displayMenu();
userInput = scanner.next().toUpperCase();
}
else if (userInput == "1") {
intakeNewDog(scanner);
break;
}
else if (userInput == "2") {
intakeNewMonkey(scanner);
break;
}
else if (userInput == "3") {
reserveAnimal(scanner);
break;
}
else if (userInput == "4") {
int number = Integer.parseInt(userInput);
printAnimals(number);
break;
}
else if (userInput == "5") {
int number = Integer.parseInt(userInput);
printAnimals(number);
break;
}
else if (userInput == "6") {
int number = Integer.parseInt(userInput);
printAnimals(number);
break;
}
}
}
// This method prints the menu options
public static void displayMenu() {
System.out.println("\n\n");
System.out.println("\t\t\t\tRescue Animal System Menu");
System.out.println("[1] Intake a new dog");
System.out.println("[2] Intake a new monkey");
System.out.println("[3] Reserve an animal");
System.out.println("[4] Print a list of all dogs");
System.out.println("[5] Print a list of all monkeys");
System.out.println("[6] Print a list of all animals that are not reserved");
System.out.println("[q] Quit application");
System.out.println();
System.out.println("Enter a menu selection");
}
// Adds dogs to a list for testing
public static void initializeDogList() {
Dog dog1 = new Dog("Moca", "German Shepherd", "male", "1", "25.6", "05-12-2019", "United States", "intake", false, "United States");
Dog dog2 = new Dog("Smokey", "Great Dane", "male", "3", "35.2", "02-03-2020", "United States", "Phase I", false, "United States");
Dog dog3 = new Dog("Pickles", "Chihuahua", "female", "4", "25.6", "12-12-2019", "Canada", "in service", true, "Canada");
dogList.add(dog1);
dogList.add(dog2);
dogList.add(dog3);
}
// Adds monkeys to a list for testing
//Optional for testing
public static void initializeMonkeyList() {
Monkey monkey1 = new Monkey("Chuckles", "Mandorin", "Female", "2", "200", "8'3", "2'", "Normal", "4/10/2023", "South America", "trained", "reserved", "service");
Monkey monkey2 = new Monkey("Nitro", "Chimpanzee", "Male", "3", "400", "7", "10'", "Muscular", "4/10/2023", "United States", "Rescue", "reserved", "service Bouncer");
Monkey monkey3 = new Monkey("Flower", "Mandorin", "Female", "2", "50", "2", "6'","Normal", "4/10/2023", "Turkey", "trained", "Rescue", "service");
monkeyList.add(monkey1);
monkeyList.add(monkey2);
monkeyList.add(monkey3);
}
public static void intakeNewDog(Scanner scanner) {
System.out.println("What is the dog's name?");
String name = scanner.nextLine();
for(Dog dog: dogList) {
if(dog.getName().equalsIgnoreCase(name)) {
System.out.println("\n\nThis dog is already in our system\n\n");
return; //returns to menu
}
}
System.out.println("What is the dog's breed?");
String breed = scanner.nextLine();
System.out.println("What is the dog's gender?");
String gender = scanner.nextLine();
System.out.println("What is the dog's age?");
String age = scanner.nextLine();
System.out.println("What is the dog's weight?");
String weight = scanner.nextLine();
System.out.println("What is the dog's acquisition date?");
String acquisitionDate = scanner.nextLine();
System.out.println("What is the dog's acquisition location?");
String acquisitionCountry = scanner.nextLine();
System.out.println("What is the dog's training status?");
String trainingStatus = scanner.nextLine();
System.out.println("Is the dog reserved?");
boolean reserved = scanner.nextBoolean();
System.out.println("What is the dog's service country?");
String inServiceCountry = scanner.nextLine();
Dog newDog = new Dog(name, breed, gender, age, weight, acquisitionDate, acquisitionCountry, trainingStatus, reserved, inServiceCountry);
dogList.add(newDog);
System.out.println("Dog added to list");
}
public static void intakeNewMonkey(Scanner scanner) {
System.out.println("What is the monkey's name?");
String name = scanner.nextLine();
for(Monkey monkey: monkeyList) {
if(monkey.getName().equalsIgnoreCase(name)) {
System.out.println("\n\nThis monkey is already in our system\n\n");
return; //returns to menu
}
}
System.out.println("What is the monkey's species?");
String species = scanner.nextLine();
System.out.println("What is the monkey's gender?");
String gender = scanner.nextLine();
System.out.println("What is the monkey's age?");
String age = scanner.nextLine();
System.out.println("What is the monkey's weight?");
String weight = scanner.nextLine();
System.out.println("What is the monkey's height?");
String height = scanner.nextLine();
System.out.println("What is the monkey's tail length?");
String tail = scanner.nextLine();
System.out.println("What is the monkey's body length?");
String body = scanner.nextLine();
System.out.println("What is the monkey's acquisition date?");
String date = scanner.nextLine();
System.out.println("What is the monkey's acquisition location?");
String country = scanner.nextLine();
System.out.println("What is the monkey's training status?");
String training = scanner.nextLine();
System.out.println("Is the monkey reserved?");
boolean reserved = scanner.nextBoolean();
System.out.println("What is the monkey's service country?");
String service = scanner.nextLine();
Monkey newMonkey = new Monkey(name, species, gender, age, weight, height, tail, body, date, country, training, reserved, service);
monkeyList.add(newMonkey);
System.out.println("Monkey added to list");
}
public static void reserveAnimal(Scanner scanner) {
scanner.nextLine();
System.out.println("Enter animal type: ");
String animalType = scanner.nextLine();
if (animalType.equalsIgnoreCase("Monkey")) {
System.out.println("Enter the monkey's country of acquisiton: ");
String country = scanner.nextLine();
for(Monkey obj: monkeyList) {
if(obj.getAcquisitionLocation().equalsIgnoreCase(country)) {
obj.setReserved(true);
System.out.println("This monkey is now reserved.");
return;
}
}
System.out.println("The monkey entered is not in the list");
}
else if (animalType.equalsIgnoreCase("Dog")) {
System.out.println("Enter the dog's country of acquisition: ");
String country = scanner.nextLine();
for(Dog obj: dogList){
if(obj.getAcquisitionLocation().equalsIgnoreCase(country)){
obj.setReserved(true);
System.out.println("This dog is now reserved.");
return;
}
}
System.out.println("The dog entered is not in the list");
} else {
System.out.println("Type not found");
}
}
public static void printAnimals(int option) {
if (option == '4') {
System.out.println(dogList);
}
else if (option == '5') {
System.out.println(monkeyList);
}
else if (option == '6') {
// Iterates through dogs
for (int i = 0; i < dogList.size(); i++) {
if (dogList.get(i).getTrainingStatus().equals("in service") &&
dogList.get(i).getReserved()==false) {
// Prints dogs that are in service and available
System.out.println(dogList.get(i));
}
}
// Iterates through monkeys
for (int i = 0; i < monkeyList.size(); i++) {
if (monkeyList.get(i).getTrainingStatus().equalsIgnoreCase("in service") &&
monkeyList.get(i).getReserved()==false) {
// Prints monkeys that are in service and available
System.out.println(monkeyList.get(i));
}
}
}
}
}
