Comparable:::::Sorting Book Object according to Book ID

package Coparable_Std;
//Sorting Book Object according to Book ID
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;

public class Book_main {

public static void main(String[] args)
{
  Book_comp book1 = new Book_comp(183,"Book1",456);
  Book_comp book2 = new Book_comp(675,"Book2",799);
  Book_comp book3 = new Book_comp(335,"Book3",5454);
  Book_comp book4 = new Book_comp(832,"Book4",454);
  Book_comp book5 = new Book_comp(331,"Book5",778);
  Book_comp book6 = new Book_comp(113,"Book6",234);
  Book_comp book7 = new Book_comp(674,"Book7",788);

  ArrayList list = new ArrayList();
  list.add(book1);
  list.add(book2);
  list.add(book3);
  list.add(book4);
  list.add(book5);
  list.add(book6);
  list.add(book7);

  Collections.sort(list);
  //System.out.println(list); // works when we overrides toString() in Book_comp & no need for below codes for iterate
  Iterator itr = list.iterator();
  while(itr.hasNext())
  {
  Book_comp book = (Book_comp) itr.next();
      System.out.println("Book ID: "+book.book_Id+" ~ Book Name: "+book.book_Name+" ~ Book Price: "+book.book_Price);
   }

}

}

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package Coparable_Std;

public class Book_comp implements Comparable<Book_comp>

{

int book_Id;

String book_Name;

double book_Price;

public Book_comp(int book_Id, String book_Name, double book_Price) 

{

super();

this.book_Id = book_Id;

this.book_Name = book_Name;

this.book_Price = book_Price;

}

public int getBook_Id() {

return book_Id;

}

public void setBook_Id(int book_Id) {

this.book_Id = book_Id;

}

public String getBook_Name() {

return book_Name;

}

public void setBook_Name(String book_Name) {

this.book_Name = book_Name;

}

public double getBook_Price() {

return book_Price;

}

public void setBook_Price(double book_Price) {

this.book_Price = book_Price;

}

/*@Override

public String toString() {

return "Book_comp [book_Id=" + book_Id + ", book_Name=" + book_Name + ", book_Price=" + book_Price + "]";

}*/

@Override

public int compareTo(Book_comp o) 

{

  if(this.book_Id > o.book_Id)

return 1;

  else

  return -1;

}

}

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