Define object as keys in Hashtable and defined objects with Hashtable in Java program

How to fetch values with user define object as keys in Hashtable

package com.java2novice.hashtable;

import java.util.Hashtable;

public class MyHashtableUserKeys

{

          public static void main(String a[])

          {

        Hashtable tm = new Hashtable();

        tm.put(new Emp(134,"Ram",3000), "Ram");

        tm.put(new Emp(235,"John",6000), "John");

        tm.put(new Emp(876,"Crish",2000), "Crish");

        tm.put(new Emp(512,"Tom",2400), "Tom");

        System.out.println("Fecthing value by creating new key:");

        Emp e = new Emp(512,"Tom",2400);

        System.out.println(e+" ==> "+tm.get(e));

    }

}

class Emp

{

              private String name;

    private int salary;

    private int id;

    public Emp(int id, String n, int s)

   {

        this.id = id;

        this.name = n;

        this.salary = s;

    } 

    public String getName()

   {

        return name;

    }

    public void setName(String name)

    {

        this.name = name;

    }

    public int getSalary()

   {

        return salary;

    }

    public void setSalary(int salary)

    {

        this.salary = salary;

    }

    public String toString()

   {

        return "Id: "+this.id+" -- Name: "+this.name+" -- Salary: "+this.salary;

    }

    public void setId(int id)

   {

        this.id = id;

    }

    public int getId()

   {

        return id;

    }

    public int hashCode()

    {

        System.out.println("In hashcode");

        return this.getId();

    }  

    public boolean equals(Object obj)

    {

        Emp e = null;

        if(obj instanceof Emp)

       {

            e = (Emp) obj;

        }

        System.out.println("In equals");

        if(this.getId() == e.getId())

       {

            return true;

        }

        else  

        {

            return false;

        }

    }

}

How to eliminate duplicate keys user defined objects with Hashtable

package com.java2novice.hashtable;

import java.util.Hashtable;

import java.util.Set;

public class MyHashtableDupEntry

{

           public static void main(String a[])

           {

        Hashtable tm = new Hashtable();

        tm.put(new Empl(134,"Ram",3000), "Ram");

        tm.put(new Empl(235,"John",6000), "John");

        tm.put(new Empl(876,"Crish",2000), "Crish");

        tm.put(new Empl(512,"Tom",2400), "Tom");

        System.out.println("Adding duplicate entry:");

        tm.put(new Empl(512,"Tom",2400), "Tom");

        System.out.println("Hashtable entries:");

        Set keys = tm.keySet();

        for(Empl key:keys)

        {

            System.out.println(key+" ==> "+tm.get(key));

         }

        System.out.println("Duplicate got eliminated!!!");

    }

}

class Empl

{

    private String name;

    private int salary;

    private int id;  

    public Empl(int id, String n, int s)

   {

        this.id = id;

        this.name = n;

        this.salary = s;

    }

    public String getName()

    {

        return name;

    }

    public void setName(String name)

   {

        this.name = name;

    }

    public int getSalary()

   {

        return salary;

    }

    public void setSalary(int salary)

   {

        this.salary = salary;

    }

    public String toString()

   {

        return "Id: "+this.id+" -- Name: "+this.name+" -- Salary: "+this.salary;

    }

    public void setId(int id)

   {

        this.id = id;

    }

              public int getId()

              {

        return id;

    }

    public int hashCode()

    {

        System.out.println("In hashcode");

        return this.getId();

    }

    public boolean equals(Object obj)

    {

        Empl e = null;

        if(obj instanceof Empl)

     {

            e = (Empl) obj;

        }

        System.out.println("In equals");

        if(this.getId() == e.getId())

         {

            return true;

        }

        else

       {

            return false;

        } 

    }

}