Use of Collection Framework

Use of Collection Framework Classes and Interfaces

ArrayList, TreeSet, Iterator

import java.util.*;

public class Book implements Comparable{

/**

Unique Book ID

                */

public int book_id;

protected String title;

/**

Book Price including GST

                */

private float price;

/**

Constructor

                */

public Book(int id, String title, float price){

this.book_id = id;

this.title = title;

this.price = price;

}

public int compareTo(Object o1){

return this.book_id-(((Book)o1).book_id);

}

public String toString(){

return this.book_id+"#"+this.title+"#"+this.price+"@";

}

public static String ObjToString(Book c[]){

String str = new String();

for(int i=0;i<c.length;i++){

str = str+c[i];

}

return str;

}

public static Book[] StringToObj(String str){

String[] st = str.split("@");

Book b2[] = new Book[st.length];

for(int i=0; i<st.length;i++){

String st1[] = st[i].split("#");

b2[i] = new Book(Integer.parseInt(st1[0]),st1[1],Float.parseFloat(st1[2]));

}

return b2;

}

public static void main(String args[]){

Book b[] = new Book[3];

b[0] =new Book(1,"Java", 100);

b[1] = new Book(2,"ADA", 200);

b[2] = new Book(3,"SP", 300);

//ArrayList a1 = new ArrayList();

TreeSet a1 = new TreeSet();

a1.add(new Book(2,"ADA", 200));

a1.add(new Book(2,"ADA", 200));

a1.add(new Book(1,"Java", 500));

a1.add(new Book(4,"MI", 800));

// Collections.sort(a1);

Iterator ir = a1.iterator();

while(ir.hasNext())

{

System.out.println((Book)(ir.next()));

}

System.out.print(a1);

/*System.out.print(Book.ObjToString(b));

String str1 = ObjToString(b);

Book c[] = StringToObj(str1);

for(int i=0;i<c.length;i++){

System.out.print(c[i]);

}*/

}

}