Design a phone book.

 

package phonebook;public class PhoneBookEntry {    private String name;    private int number;        public PhoneBookEntry(String name, int number) {       this.name = name;       this.number = number;    }        public void changeNumber(int newnum) {            number = newnum;    }        public String getName(){        return name;    }    public int getNumber(){        return number;    }    // Changes the last name for the current object to newlastname.    public void changeLastName(String newlastname) {            name = newlastname;    }//    @Override//    public int hashCode() {//        // TODO Auto-generated method stub//        return this.name.hashCode();//    }////    @Override//    public String toString() {//        // TODO Auto-generated method stub//        return name + " " ;//    }////    @Override//    public boolean equals(Object obj) {//        // TODO Auto-generated method stub//        if(obj == null)//            return false;//        if(obj == this)//            return true;//        if((getClass()!=obj.getClass()))//            return false;//        PhoneBookEntry e = (PhoneBookEntry)obj;//        return this.getName() == e.getName();//    }        }

 

 

package phonebook;import java.util.Comparator;import java.util.HashSet;import java.util.TreeSet;public class PhoneBook {        public TreeSet
     
       set;    // for look up    private HashMap
      
       ();    private final int MAX_SIZE = 100;    /**     * @param args     */    public PhoneBook(){         set = new TreeSet
       
        (new myCompare());    }        public void print(){        for(PhoneBookEntry entry : set)            System.out.println(entry.getName()+ " " + entry.getNumber());    }        public boolean isFull(){        return set.size() > MAX_SIZE;     }        public boolean add(String name, int num){        if(!isFull()){            PhoneBookEntry e = new PhoneBookEntry(name,num);            if(set.contains(e)){            System.out.println("exist");            return false;            }            else            set.add(e);            return true;        }        return false;    }        public boolean remove(String name){         PhoneBookEntry e = new PhoneBookEntry(name,0);         if(set.contains(e)){             System.out.println("remove elm exist");}         else             System.out.println("remove elm not exist");             }    public static void main(String[] args) {        // TODO Auto-generated method stub        PhoneBook book = new PhoneBook();        book.add("a",10);        book.add("bsdf",10);        book.add("bd",10);        book.add("a3",10);        book.add("a2",10);        book.add("a22",10);        book.add("zdfsd",10);        book.print();        }        } class myCompare implements Comparator
        
         {    @Override    public int compare(PhoneBookEntry o1, PhoneBookEntry o2) {        // TODO Auto-generated method stub        return o1.getName().compareTo(o2.getName());    }}