我是一名Java编程的学生，正忙碌一项作业。我真的很感激一些帮助。
下面是我必须创建的类：

/**
 * Class for basic dog data: name, age, weight, breed and booster shot info.
 */
public class Dog {
    private String name; //name of dog
    private int age; //in years
    private double weight;  //in pounds
    private String breed; //breed of dog
    private boolean boosterShot; //Status of booster shot

    public Dog() {
        name = "No name yet.";
        age = 0;
        weight = 0;
        breed = "No breed yet.";
        this.boosterShot = false;
    }

    public Dog(String initialName, int initialAge,
               double initialWeight, String initialBreed, boolean boosterShot) {
        name = initialName;
        if ((initialAge < 0) || (initialWeight < 0)) {
            System.out.println("Error: Negative age or weight.");
            System.exit(0);
        } else {
            age = initialAge;
            weight = initialWeight;
            breed = initialBreed;
            this.boosterShot = boosterShot;
        }
    }

    public Dog(String initialName, String initialBreed, boolean boosterShot) {
        name = initialName;
        age = 0;
        weight = 0;
        breed = initialBreed;
        this.boosterShot = boosterShot;
    }

    public Dog(int initialAge) {
        name = "No name yet.";
        weight = 0;
        breed = "No breed yet.";
        boosterShot = false;
        if (initialAge < 0) {
            System.out.println("Error: Negative age.");
            System.exit(0);
        } else
            age = initialAge;
    }

    public Dog(double initialWeight) {
        name = "No name yet.";
        age = 0;
        breed = "No breed yet.";
        boosterShot = false;
        if (initialWeight < 0) {
            System.out.println("Error: Negative weight.");
            System.exit(0);
        } else
            weight = initialWeight;
    }

    public void setDog(String newName, int newAge,
                       double newWeight, String newBreed, boolean boosterShot) {
        name = newName;
        if ((newAge < 0) || (newWeight < 0)) {
            System.out.println("Error: Negative age or weight.");
            System.exit(0);
        } else {
            age = newAge;
            weight = newWeight;
            breed = newBreed;
            this.boosterShot = boosterShot;
        }
    }

    public boolean hadBoosterShot() {
        return this.boosterShot;
    }

    public String getName() {
        return name;
    }

    public void setName(String newName) {
        name = newName; //age and weight are unchanged.
    }

    public int getAge() {
        return age;
    }

    public void setAge(int newAge) {
        if (newAge < 0) {
            System.out.println("Error: Negative age.");
            System.exit(0);
        } else
            age = newAge; //name and weight are unchanged.
    }

    public double getWeight() {
        return weight;
    }

    public void setWeight(double newWeight) {
        if (newWeight < 0) {
            System.out.println("Error: Negative weight.");
            System.exit(0);
        } else
            weight = newWeight; //name and age are unchanged.
    }

    public String getBreed() {
        return breed;
    }

    public void setBreed(String newBreed) {
        breed = newBreed;
    }

    public boolean getBoosterShot() {
        return boosterShot;
    }

    public void setBoosterShot(boolean boosterShot) {
        this.boosterShot = boosterShot;
    }

    public void writeOutput() {
        System.out.println("Name: " + name);
        System.out.println("Age: " + age + " years");
        System.out.println("Weight: " + weight + " pounds");
        System.out.println("Breed: " + breed);
        System.out.println("Booster shot status: " + boosterShot);
    }
}

下面是我创建的测试程序：

import java.util.Scanner;

public class DogDemo {
    public static void main(String[] args) {
        Dog a = new Dog();
        System.out.println("My records on your dog are inaccurate.");
        System.out.println("Here is what they currently say:");
        a.writeOutput();

        Scanner keyboard = new Scanner(System.in);

        System.out.println("Please enter the correct dog name:");
        String correctName = keyboard.nextLine();
        a.setName(correctName);

        System.out.println("Please enter correct dog breed:");
        String correctBreed = keyboard.nextLine();
        a.setBreed(correctBreed);

        System.out.println("Please enter the correct dog age:");
        int correctAge = keyboard.nextInt();
        a.setAge(correctAge);

        System.out.println("Please enter the correct dog weight:");
        double correctWeight = keyboard.nextDouble();
        a.setWeight(correctWeight);

        System.out.println("My updated records now say:");
        a.writeOutput();
    }
}

所有工作正常，但我真的卡住了如何设置boosterShot到true或false在测试程序。
任何帮助都将不胜感激。