空指针异常 帮忙看看怎么处理
package www.imooc;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class PlayingGames {
/**
* @param args
*/
public List<Card> cardlist=new ArrayList<Card>();
public List<Player> playerlist=new ArrayList<Player>();// 用来放创建的玩家
public List<Card> cardlist1=new ArrayList<Card>(); //用于放玩家拿到的纸牌
/**
* 定义创建纸牌的方法
*/
public void CreatCards(){
String[] size={"2","3","4","5","6","7","8","9","10","J","Q","K","A"};
String[] huase={"方块","梅花","红桃","黑桃"};
for(int i=0;i<huase.length;i++){
for(int j=0;j<size.length;j++){
cardlist.add(new Card(huase[i],size[j]));
}
}
System.out.println("共添加了"+cardlist.size()+"张扑克牌");
for (Card cr : cardlist) {
System.out.print(cr.huase+cr.size+",");
}
}
public void sortcard(){
Collections.shuffle(cardlist);
System.out.println("洗牌结束");
}
public void createcard(){
CreatCards();
sortcard();
}
/**
* 创建玩家
* @param args
*/
public void CreatPlayer(){
for(int i=1;i<3;i++){
Scanner console=new Scanner(System.in);
Player player=new Player();
System.out.println("请输入第"+i+"位的ID和姓名");
for(int j=0;j<2;j++){
try{
String id=console.next();
player.ID=id;
break;
}catch(Exception e){
System.out.println("请输入一个整数ID");
continue;
}finally{
}
}
System.out.println("请输入第"+i+"位玩家的姓名");
String name=console.next();
player.name=name;
playerlist.add(player);
}
for (Player pl : playerlist) {
System.out.println(pl.ID+":"+pl.name);
}
}
public void GiveCards(){
int num=0;
for(int i=0;i<4/playerlist.size();i++){
for (Player player : playerlist) {
player.cards.add(cardlist.get(num));
num++;
}
}
for (Player player : playerlist) {
for (Card card : player.cards) {
System.out.println(player.name+":"+card.huase+card.size);
}
}
}
public static void main(String[] args) {
//
PlayingGames pg=new PlayingGames();
pg.createcard();
pg.CreatPlayer();
pg.GiveCards();
}
}
package www.imooc;
import java.util.ArrayList;
import java.util.List;
public class Player {
public String ID;
public String name;
public List<Card> cards;
public Player(String id,String name){
this.ID=id;
this.name=name;
cards=new ArrayList<Card>();
}
public Player(){
}
}
package www.imooc;
public class Card {
public String huase;
public String size;
public Card(String huase,String size) {
// TODO Auto-generated constructor stub
this.huase=huase;
this.size=size;
}
public Card(){
}
}
Exception in thread "main" java.lang.NullPointerException
at www.imooc.PlayingGames.GiveCards(PlayingGames.java:83)
at www.imooc.PlayingGames.main(PlayingGames.java:104)
