java - Design and implement a class called Card that represents a standard playing card -

here issue, have created class incomplete because having issues on 2 levels. might tired...so bear me please.

1. i having issue trying resolve having 5 random cards generate , not 1 more important no duplicates.
2. i still new every time try add main says variables haven't been initialized. wtf...this biggest program/ first class have had write , stuck.

help please

import java.util.*;  public class card      {         private int suit;  // initializes 2 variables card         private int value;  public card()  // constructor of card creates random suit , value card      {             random num = new random();      suit = num.nextint(4);      value = num.nextint(13)+1;     }          public card(int card_suit, int card_value)  // constructor of card takes int representing suit , value             {                 suit = card_suit;                 value = card_value;             }              public int getvalue()  // returns numeric value of card                     {                     return value;                 }                  public int getsuit()  // returns numeric coded value of card' suit                      {                         return suit;                     }       public string getsuitasstring()  // return string representing card's suit.                                     // (if card's suit invalid, "??" returned.)    {      switch ( suit )       {         case 3: return "spades";          case 2: return "hearts";          case 1: return "diamonds";          case 0: return "clubs";          default: return "??";       }     }           public string getvalueasstring()  // return string representing card's value.                                           // if card's value i// compares value of card, value, int, of card                                           // returns true if value > other card, false if not invalid, "??" returned.         {             switch ( value )             {                 case 1: return "ace";                  case 2: return "2";                  case 3: return "3";                  case 4: return "4";                  case 5: return "5";                  case 6: return "6";                  case 7: return "7";                  case 8: return "8";                  case 9: return "9";                  case 10: return "10";                  case 11: return "jack";                  case 12: return "queen";                  case 13: return "king";                  default: return "??";             }          }          public string tostring()  // overrides tostring method,         {             return getvalueasstring() + " of " + getsuitasstring(); // return string representation of card, such                                                                     // "10 of hearts" or "queen of spades".         }           public boolean comparevalue(int cardother)         {              return value > cardother;          }               } 

imo have 2 options rid of problem-1:

1. override equals method based on suit_value combo , every time create object of put in list after checking if exist or not. if exists create new 1 else keep , put in list.

2. similar before instead of list use map key suit+value -> respective obj.