Question

public void changeOwner(BookStoreOwner currentOwner, BookStoreOwner newOwner)

Allows the current owner of this book store to give this book store to a new owner.

Parameters: currentOwner - the current owner of this book store newOwner - the new owner of this book store

Throws: java.lang.IllegalArgumentException - if currentOwner reference is not the reference of the current owner of this book store

Answer 1

Any questions on top of this I am ready to explain that for you

SOLUTION:

package testing;

public class BookStoreOwner {
   //i have created some sample fields of owner
   private String name;
   private String id;
   private int age;
   private String address;
   //gettters and setters for that with to string
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public String getId() {
       return id;
   }
   public void setId(String id) {
       this.id = id;
   }
   public int getAge() {
       return age;
   }
   public void setAge(int age) {
       this.age = age;
   }
   public String getAddress() {
       return address;
   }
   public void setAddress(String address) {
       this.address = address;
   }
   public void changeOwner(BookStoreOwner currentOwner, BookStoreOwner newOwner) throws IllegalArgumentException{
       System.out.println("current owner "+currentOwner.toString());
       //details before updating the currentowner
       currentOwner.setName(newOwner.getName());
       currentOwner.setId(newOwner.getId());
       currentOwner.setAge(newOwner.getAge());
       currentOwner.setAddress(newOwner.getAddress());
       //updated current owner details to new owner
       System.out.println("New Owner is "+currentOwner.toString());
   }
   @Override
   public String toString() {
       return "BookStoreOwner [name=" + name + ", id=" + id + ", age=" + age + ", address=" + address + "]";
   }
   public static void main(String[] args) {
       //create instance of current ownner
       BookStoreOwner currentOwner=new BookStoreOwner();
       currentOwner.setName("name");
       currentOwner.setId("123");
       currentOwner.setAge(20);
       currentOwner.setAddress("New jersey");
       //create instance of new ownere
       BookStoreOwner newOwner=new BookStoreOwner();
       newOwner.setName("name1");
       newOwner.setId("124");
       newOwner.setAge(25);
       newOwner.setAddress("New York");
       //call the change owner method
       BookStoreOwner test=new BookStoreOwner();
       test.changeOwner(currentOwner, newOwner);
      
   }

}

Code image and output: