Question

java problem

Create an implementation for the class DoorLock described below 1. Declare an integer constant, called MAX NUMBER.OF_ATTEMPTS, that vou will initialize to the value 6: 2. Instance variables. The class DoorLock must have the necessary instance variables tO: I Store an object of the class Combination II To represent the property of being opened or closed III To represent its state (the door lock is enabled or disabled) IV To count the number of unsuccessful attempts at opening the door; 3. The class has a single constructor, DoorLock( Combination combination ), which initializes this instance with a combination. When a door lock i:s first created, the door lock is closed. Also, when the object is first created it is enabled and the number of failed attempts at opening it should be zero 4. Implement the instance method public boolean isOpen) that returns true if this door lock is currently opened and false otherwise 5. Implement the instance method public boolean isEnabled() that returns true if this door lock is currently enabled and false otherwise. 6. Implement the instance method public void enable( Combination c) that sets the instance variable enabled to true if the parameter c is equals to the combination of this object; 7. Finally, implement the instance method public boolean open( Combina- tion combination such that: I An attempt is made at opening this door lock only if this door lock is enabled II If the parameter combination is equals to the combination of this door lock, set the state of the door to be open, and the number of failed attempts should be reset to zero

here is the combination class

class Combination
{
   int first,second,third, fourth;

   public Combination(int first, int second, int third,int fourth)
   {
       this.first=first;
       this.second=second;
       this.third=third;
       this.fourth=fourth;
   }

   public boolean equals(Combination other)
   {
      
       if ((this.first==other.first) && (this.second==other.second) && (this.third==other.third) && (this.fourth==other.fourth))
           return true;
       else
           return false;
   }

   public String toString()
   {

       return first+":"+second+":"+third+":"+fourth;
   }
}
public class CombinationEx
{
   public static void main(String args[])
   {

       Combination c1=new Combination(1,2,3,4);
       Combination c2=new Combination (1,2,3,4);
       Combination c3=new Combination(4,5,6,7);

       boolean r1=c1.equals(c2);
       System.out.println( "c1 equals c2 "+ r1);

       boolean r2=c1.equals(c3);
       System.out.println("c1 equals c3 "+r2);

       System.out.println(c1);
       System.out.println(c3);
   }
}

Answer 1

Thanks for the question.

Here is the completed code for this problem.  Let me know if you have any doubts or if you need anything to change.

Thank You !!

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

public class DoorLock {

    public static final int MAX_NUMBER_OF_ATTEMPTS = 6;
    private Combination combination;
    private boolean isOpen;
    private boolean isEnabled;
    private int failedAttempts;

    public DoorLock(Combination combination) {
        this.combination = combination;
        isOpen = false;
        isEnabled = true;
        failedAttempts = 0;
    }

    public boolean isOpen() {
        return isOpen;
    }

    public boolean isEnabled() {
        return isEnabled;
    }

    public void enable(Combination c) {
        if (combination.first == c.first && combination.second == c.second &&
                combination.third == c.third && combination.fourth == c.fourth) {
            isEnabled = true;
        }
    }

    public boolean open(Combination c) {
        if (isEnabled) {
            if (combination.first == c.first && combination.second == c.second &&
                    combination.third == c.third && combination.fourth == c.fourth) {
                isOpen = true;
                failedAttempts = 0;
                return true;
            } else {
                failedAttempts++;
                if (failedAttempts == MAX_NUMBER_OF_ATTEMPTS) {
                    isEnabled = false;

                }
            }
        }
        return false;
    }

}

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