hash table

import java.util.*;
import java.io.*;

public class hash1{
  public static void main(String[] args) throws IOException{
  int key;
  try{
  BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
  System.out.print("How many elements you want to enter to the hash table : ");
  int n = Integer.parseInt(in.readLine());
  Hashtable<Integer, String> hashTable = new Hashtable<Integer, String>();
  for(int i = 0; i < n; i++){
  System.out.print("Enter key for the hash table : ");
  key = Integer.parseInt(in.readLine());
  System.out.print("Enter value for the key : ");
  hashTable.put(key, in.readLine());
  }
  Map<Integer, String> map = new TreeMap<Integer, String>(hashTable);
  System.out.println(map);
  }
  catch(NumberFormatException ne){
  System.out.println(ne.getMessage() + " is not a legal value.");
  System.out.println("Please enter a numeric value.");
  System.exit(1);
  }
  }
}