我一直在制作纸牌游戏 Gin Rummy 的基本模拟，虽然目前还不完整，但它能够运行一副纸牌的基本功能，直到我试过实现一种方法来处理每个玩家的手。
班级Player应该由ArrayList（每个玩家手中持有牌）和integer（用作玩家ID）组成。我已将这些对象声明为static，但当然这意味着我创建的每个Player实例都具有相同的Hand和playerid，因为变量是静态的。
这是我当时面临的问题。我始终相信任何static类或方法，只能访问其他static类，方法对象等。因为main方法必须是static，所以它肯定是任何东西可以访问也必须static等等等等？我的Player类中的对象如何不是静态的，因此允许我为Player的每个实例分配不同的Hand和playerid？
我已将我的代码包含在下面，我很抱歉它已经很久了，我以为我会把所有东西放进去以防万一。对于记录，它是PlayGinRummy类中的一些点，我将Player的新实例称为抛出错误non-static variable Hand cannot be referenced from a static context。
package labexercise1;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;
public class DeckOfCardsTest {
public DeckOfCardsTest(){}
private static int Menu;
public static void main(String[] args) throws InterruptedException{
DeckOfCards.FillDeck();
do{
Thread.sleep(1000);
System.out.println("Please select from the following menu options using the corresponding number:");
System.out.println("1. Display Deck | 2. Shuffle Deck | 3. Cut Deck | 4. Start Game | 5. Exit"); //Start game will lead into another switch menu to set no of players etc.
System.out.print("Your choice: ");
Scanner UserInput = new Scanner(System.in);
System.out.println();
Menu = UserInput.nextInt(); // Maybe build in a system that recognises, for example, "1", "one" and "One" as the menu selection 1, using if/else
System.out.println();
switch(Menu){
case 1:
DeckOfCards.DisplayDeck();
break;
case 2:
DeckOfCards.ShuffleDeck();
break;
case 3:
DeckOfCards.CutDeck();
break;
case 4:
PlayGinRummy.DealDeck(); // Maybe shuffle things around so this just calls a method in player, from which everything else is called. Would mean moving things over from DeckOfCards so Player had access to hp, cp1, cp2 and cp3.
break;
case 5:
System.out.println("The program will now end.");
System.out.println();
break;
default:
System.out.println("Your input is not a valid selection.");
System.out.println();
break;
}
} while(Menu!=5);
}
public class DeckOfCards {
public DeckOfCards(){}
public static ArrayList<Integer> Deck = new ArrayList<>();
public static ArrayList<Integer> Discard = new ArrayList<>();
public static void FillDeck() throws InterruptedException{
System.out.print("Compiling deck");
DeckOfCards.CountdownEffect();
for(int count=0; count<52; count++){
Deck.add(count);
}
System.out.println(" Deck compiled!");
System.out.println();
}
public static void DisplayDeck() throws InterruptedException{
System.out.println("Displaying deck contents:");
Thread.sleep(1000);
for(int count=0; count<52; count++){
System.out.println(Deck.get(count));
}
System.out.println();
}
public static void ShuffleDeck() throws InterruptedException{
System.out.print("Shuffling deck");
Thread.sleep(1000);
for(int count=0; count<3; count++){
System.out.print(".");
Thread.sleep(1000);
}
Collections.shuffle(Deck);
System.out.println(" Deck shuffled!");
System.out.println();
}
public static void CutDeck() throws InterruptedException{
System.out.print("Cutting deck");
Thread.sleep(1000);
for(int count=0; count<3; count++){
System.out.print(".");
Thread.sleep(1000);
}
System.out.println();
System.out.println("The cut card is:");
Random random = new Random();
int CutPoint = 51 - (random.nextInt(52));
System.out.println(Deck.get(CutPoint));
System.out.println();
}
public static void CountdownEffect() throws InterruptedException{
Thread.sleep(1000);
for(int count=0; count<3; count++){
System.out.print(".");
Thread.sleep(1000);
}
}
}
public class Player{
public Player(ArrayList<Integer> h, int id, int n){
Hand = new ArrayList<>(h);
playerid = id;
NoOfPlayers = n;
}
public ArrayList<Integer> Hand;
public int playerid;
public static int NoOfPlayers;
public int SizeOfHand(){
int s = Hand.size();
return s;
}
public void DisplayHand() throws InterruptedException{
System.out.print("Displaying ");
if (playerid==1)
System.out.print("player's");
else if (playerid==2)
System.out.print("computer player 1's");
else if (playerid==3)
System.out.print("computer player 2's");
else if (playerid==4)
System.out.print("computer player 3's");
System.out.println(" hand:");
Thread.sleep(1000);
for(int count=0; count<7; count++){
if (count<6)
System.out.print(Hand.get(count) + ", ");
else if (count==6)
System.out.println(Hand.get(count) + ".");
}
}
}
public class PlayGinRummy {
public PlayGinRummy(){}
public static int NoOfPlayers;
public static void DealDeck() throws InterruptedException{
int cardno, playerno; // Tracks index of top card
System.out.println("Please input the desired number of players (2-4): ");
Scanner UserInput = new Scanner(System.in);
NoOfPlayers = UserInput.nextInt();
System.out.println();
System.out.println();
cardno=51;
playerno=0;
do{
if (NoOfPlayers==2){
Player hp = new Player(Player.Hand,1,NoOfPlayers);
Player cp1 = new Player(Player.Hand,2,NoOfPlayers);
do{
if (playerno%2==0)
hp.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%2==1)
cp1.Hand.add(DeckOfCards.Deck.get(cardno));
DeckOfCards.Deck.remove(cardno);
playerno++;
cardno--;
}while(hp.SizeOfHand()!=7 && cp1.SizeOfHand()!=7);
hp.DisplayHand();
cp1.DisplayHand();
}
else if (NoOfPlayers==3){
Player hp = new Player(Player.Hand,1,NoOfPlayers);
Player cp1 = new Player(Player.Hand,2,NoOfPlayers);
Player cp2 = new Player(Player.Hand,3,NoOfPlayers);
do{
if (playerno%3==0)
hp.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%3==1)
cp1.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%3==2)
cp2.Hand.add(DeckOfCards.Deck.get(cardno));
DeckOfCards.Deck.remove(cardno);
playerno++;
cardno--;
}while(hp.SizeOfHand()!=7 && cp1.SizeOfHand()!=7 && cp2.SizeOfHand()!=7);
hp.DisplayHand();
cp1.DisplayHand();
cp2.DisplayHand();
}
else if (NoOfPlayers==4){
Player hp = new Player(Player.Hand,1,NoOfPlayers);
Player cp1 = new Player(Player.Hand,2,NoOfPlayers);
Player cp2 = new Player(Player.Hand,3,NoOfPlayers);
Player cp3 = new Player(Player.Hand,4,NoOfPlayers);
do{
if (playerno%4==0)
hp.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%4==1)
cp1.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%4==2)
cp2.Hand.add(DeckOfCards.Deck.get(cardno));
else if (playerno%4==3)
cp3.Hand.add(DeckOfCards.Deck.get(cardno));
DeckOfCards.Deck.remove(cardno);
playerno++;
cardno--;
}while(hp.SizeOfHand()!=7 && cp1.SizeOfHand()!=7 && cp2.SizeOfHand()!=7 && cp3.SizeOfHand()!=7);
hp.DisplayHand();
cp1.DisplayHand();
cp2.DisplayHand();
cp3.DisplayHand();
}
else{
System.out.println("The choice made is invalid, please try again.");
System.out.println();
}
}while(NoOfPlayers!=2 && NoOfPlayers!=3 && NoOfPlayers!=4);
System.out.println();
}
}
答案 0 :(得分：2)
由于“main”方法必须是静态的，当然它可以访问的任何东西也必须是静态的等等吗？
没有。静态方法可以访问实例方法。他们通过使用实例来实现这一目标。 main创建实例以使用实例方法（类main本身或其他类中的任何一种）非常非常常见。
总的来说：
public static final void main(String[] args) {
SomeClass instance = new SomeClass();
instance.method();
}
如果你正在创造一些小而且完全独立的东西，main创建它所在的类是很常见的。例如：
public class Simple {
private String name;
public static final void main(String[] args) {
// Create a couple of instances
Simple s1 = new Simple();
Simple s2 = new Simple();
// Use instance methods
s1.setName("s1");
s2.setName("s2");
System.out.println(s1.getName());
System.out.println(s2.getName());
}
private void setName(String name) {
this.name = name;
}
private String getName() {
return this.name;
}
}
在那里，我使用了两个独立的实例来强调。我为它们使用了单独的变量，但当然如果您要将它们视为分组列表或实例集，您可能使用数组List或Set。数组示例：
public class Simple {
private String name;
public static final void main(String[] args) {
// Create the array (no instances are created)
Simple[] simples = new Simple[2];
// Create a couple of instances, set their names
for (int n = 0; n < simples.length; ++n) {
simples[n] = new Simple();
simples[n].setName("s[" + n + "]");
}
// Use instance methods
for (Simple s : simples) {
System.out.println(s.getName());
}
}
private void setName(String name) {
this.name = name;
}
private String getName() {
return this.name;
}
}