问题
I've been practicing a project which is the classical Nim game. What I've achieved now is:
- Add, remove, edit, display, players. (Nimsys and NimPlayer)
- Selecting two players to play a game. (NimGame class)
Every time when the game ends, I need to return these two things from NimGame to NimPlayer. Then I can use getter in Nimsys:
- If the player wins, his/her score +1.
- Every time after a game, the number of game +1 for the player who played.
What I've already tried was to pass the "score" and "gamePlayed" from NimPlayer to NimGame, putting the getter, which is 0 at first, in the setter to set the number +1.
scores = NimPlayer.setScore(NimPlayer.getScore() + 1);
However, I don't know how to pass the "scores" here back to NimPlayer to be used. I am hoping to pass the scores back to NimPlayer. Then, I can call it from Nimsys. Here is my code.
import java.util.Scanner;
public class Nimsys {
public static String[] splitName(String inName) {
String[] splittedLine = inName.split(",");
String[] name = null;
if (splittedLine.length==3) {
String userName = splittedLine[0].trim();
String familyName = splittedLine[1].trim();
String givenName = splittedLine[2].trim();
name = new String[3];
name[0] = userName;
name[1] = familyName;
name[2] = givenName;
}
return name;
}
public static String [] splitData(String dataIn) {
String[] splittedLine = dataIn.split(",");
String[] data = null;
if (splittedLine.length==4) {
String initialStone = splittedLine[0];
String stoneRemoval = splittedLine[1];
String player1 = splittedLine[2].trim();
String player2 = splittedLine[3].trim();
data = new String[4];
data[0] = initialStone;
data[1] = stoneRemoval;
data[2] = player1;
data[3] = player2;
}
return data;
}
public static String playerChecker(String name) {
String player = null;
for (int i = 0; i < NimPlayer.getId(); i++) {
player = NimPlayer.getPlayer()[i].getUserName();
if (player.equals(name)) {
break;
}
}
return player;
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (true) {
System.out.print('$');
String commandin = in.next();
if (commandin.equals("addplayer")) {
String inName = in.nextLine();
String[] name = splitName(inName);
//Make sure the vadality of in name
//Can use playerCheck to simplify the code
if (name!=null && name.length==3) {
for (int i = 0; i < NimPlayer.getId(); i ++) {
String userCheck = NimPlayer.getPlayer()[i].getUserName();
if (userCheck.contains(name[0])) {
System.out.println("The player already exist");//Test if player has been created
}
}
NimPlayer.createPlayer(name[0], name[1], name[2], 0, 0);
System.out.println("The player has been created.");
} else {
System.out.println("Not Valid! Please enter again!");
}
}
if (commandin.equals("removeplayer")) {
//cannot loop through the entire null array, would be NullPointerException
String removeUserName = in.nextLine().trim();
/*System.out.println("Are you sure you want to remove all players? (y/n) \n");
//System.out.print('$');
commandin = in.next();
if (commandin.equals("y")) {
for (int i = 0; i < NimPlayer.getId(); i++) {
NimPlayer.getPlayer()[i] = null;
System.out.println("Remove all the players");
}
} else {
System.out.print('$');
}*/
//commandin = in.next();
for (int i = 0; i < NimPlayer.getId(); i++) {
String userName = NimPlayer.getPlayer()[i].getUserName().trim();
if (removeUserName != null && userName.equals(removeUserName)) {
NimPlayer.getPlayer()[i] = null;
System.out.println("Remove successfully!");// A test to see if the code runs
} else {
System.out.println("The player does not exist");
}
}
}
if (commandin.equals("editplayer")) {
String inName = in.nextLine();
String[] splittedLine = inName.split(",");
if (splittedLine!=null && splittedLine.length==3) {
String userName = splittedLine[0].trim();
String familyName = splittedLine[1].trim();
String givenName = splittedLine[2].trim();
//System.out.println(userName+","+familyName+","+givenName);//Test if in name in the if loop
for (int i = 0; i < NimPlayer.getId(); i++) {
String userCheck = NimPlayer.getPlayer()[i].getUserName().trim();
if (userName != null && userCheck.equals(userName)) {
NimPlayer.getPlayer()[i].setFamilyName(familyName);
NimPlayer.getPlayer()[i].setGivenName(givenName);
System.out.println("Edit successfully");
} else {
System.out.println("The player does not exist.");
}
}
} else {
System.out.println("Invalid in! Please enter again.");
}
}
if (commandin.equals("displayplayer")) {
String user = in.nextLine().trim();
for (int i = 0; i < NimPlayer.getId(); i++) {
String userCheck = NimPlayer.getPlayer()[i].getUserName().trim();
String userName = NimPlayer.getPlayer()[i].getUserName();
String familyName = NimPlayer.getPlayer()[i].getfamilyName();
String givenName = NimPlayer.getPlayer()[i].getGivenName();
int score = NimPlayer.setScore(NimPlayer.getScore());
int gamePlayed = NimPlayer.setGamePlayed(NimPlayer.getGamePlayed());
if (user != null && userCheck.equals(user)) {
System.out.println(userName+","+familyName+","+givenName+","+gamePlayed+" games,"+score +" wins");
}
}
}
if (commandin.equals("startgame")) {
String dataIn = null, player1 = null, player2 = null;
do {
dataIn = in.nextLine();
String [] data = splitData(dataIn);
if (data != null && data.length==4) {
player1 = playerChecker(data[2]);
player2 = playerChecker(data[3]);
NimGame game = new NimGame(data[0].trim(), data[1], player1, player2);
game.playGame(data[0].trim(), data[1], player1, player2);
}
} while(player1 == null || player2 == null);
}
}
}
}
The above is my main method Nimsys. I have a problem calling these values using the displayplayer command. It should be like this:
userName,familyName,givenName,gamePlayed "games",score "wins"
Below is my NimPlayer class:
//username, given name, family name, number of game played, number of games won
public class NimPlayer {
private String userName;
private String familyName;
private String givenName;
private static int score;
private static int gamePlayed;
static int id;
static NimPlayer[] playerList = new NimPlayer[10]; // set an array here
//define NimPlayer data type
public NimPlayer(String userName, String surName, String givenName, int gamePlayed, int score) {
this.userName = userName;
this.familyName = surName;
this.givenName = givenName;
NimPlayer.score = score;
NimPlayer.gamePlayed = gamePlayed;
}
// create new data using NimPlayer data type
public static void createPlayer(String userName, String familyName, String givenName, int gamePlayed, int score) {
if (id<10) {
playerList[id++] = new NimPlayer(userName, familyName, givenName, gamePlayed, score);
} else {
System.out.println("Cannot add more players.");
}
}
public static int getId() {
return id;
}
public static NimPlayer [] getPlayer() {
return playerList;
}
public void setUserName(String userName) {
this.userName = userName;
}
public void setFamilyName(String familyName) {
this.familyName = familyName;
}
public void setGivenName(String givenName) {
this.givenName = givenName;
}
public String getUserName() {
return userName;
}
public String getfamilyName() {
return familyName;
}
public String getGivenName() {
return givenName;
}
public static int setScore(int score) {
return score;
}
public static int getScore() {
return score;
}
public static int setGamePlayed (int gamePlayed) {
return gamePlayed;
}
public static int getGamePlayed() {
return gamePlayed;
}
}
And finally the NimGame part:
import java.util.Scanner;
//playing process
//current stone count
//upper bound on stone removal
//two players
public class NimGame {
private static int gamePlayed;
private static int scores;
String player1;
String player2;
String playOrNot;
String initialStoneInput;
String dataRemoval;
int stars;
int stoneBalance;
int initialStone;
int upperBound;
public int initializeStone(int startStones) {
stoneBalance = startStones;
return stoneBalance;
}
public void removeStones(int stonesTaken) {
int updatedBalance = stoneBalance - stonesTaken;
stoneBalance = updatedBalance;
}
public void printStar(int star) {
stars = star;
stars = stoneBalance;
for (int stars = 1; stars <= star; stars++) {
System.out.print(" *");
}
System.out.println();
}
public static int earnPoint(String player) {
for (int i = 0; i < NimPlayer.getId(); i++) {
String playerCheck = NimPlayer.getPlayer()[i].getUserName();
if (playerCheck.equals(player)) {
scores = NimPlayer.setScore(NimPlayer.getScore() + 1);
}
}
return scores;
}
public static int gamePlayed(String player) {
for (int i = 0; i < NimPlayer.getId(); i++) {
String playerCheck = NimPlayer.getPlayer()[i].getUserName();
if (playerCheck.equals(player)) {
gamePlayed = NimPlayer.setGamePlayed(NimPlayer.getGamePlayed() + 1);
}
}
return gamePlayed + 1;
}
public int getGameScore() {
return scores;
}
public int getNumberGamePlayed() {
return gamePlayed;
}
public NimGame (String initialStone ,String dataRemoval,String player1, String player2) {
this.initialStoneInput = initialStone;
this.dataRemoval = dataRemoval;
this.player1 = player1;
this.player2 = player2;
}
Scanner in = new Scanner(System.in);
public void playGame (String initialStone ,String dataRemoval,String player1, String player2) {
//Convert user input string into integer
int initialStoneInt = Integer.parseInt(initialStoneInput);
initializeStone(initialStoneInt);
int upperBound = Integer.parseInt(dataRemoval);
System.out.println("Initial stone count: "+initialStoneInt);
System.out.println("Maximum stone removal: "+dataRemoval);
System.out.println("Player 1: "+player1);
System.out.println("Player 2: "+player2);
do {
// while stoneBalance > 0, two players keep playing the game
while (stoneBalance > 0) {
// player1's turn and remove the stones; decision of winning
System.out.println(player1 + "'s turn - remove how many?\n");
int takeStone = in.nextInt();
while (takeStone > upperBound || takeStone <= 0) {
System.out.println(
"Invalid, you need to remove stones under upper "+
"bound limit or above 0. \n Please enter again.");
takeStone = in.nextInt();
}
removeStones(takeStone); //remove the stone
if (stoneBalance > 0) {
//show the remaining stones
System.out.print(stoneBalance + " stones left:");
printStar(stoneBalance);
} else if (stoneBalance <= 0) {
System.out.println("Game Over\n" + player2 + " wins!\n");
earnPoint(player2);
break;
}
// player2's turn and remove the stones; decision of winning
System.out.println(player2 + "'s turn - remove how many?\n");
takeStone = in.nextInt();
while (takeStone > upperBound || takeStone <= 0) {
System.out.println(
"Invalid, you need to remove stones under upper " +
"bound limit or above 0. \n Please enter again.");
takeStone = in.nextInt();
}
removeStones(takeStone);
if (stoneBalance > 0) {
System.out.print(stoneBalance + " stones left:");
printStar(stoneBalance);
} else if (stoneBalance <= 0) {
System.out.println("Game Over\n" + player1 + " wins!\n");
earnPoint(player1);
break;
}
}
// ask players to play again
//in.nextLine();
System.out.println("Do you want to play again (Y/N):");
playOrNot = in.nextLine();
gamePlayed(player1);
gamePlayed(player2);
} while (playOrNot.equals("Y"));
}
}
回答1:
The following things need to be addressed in your code:
- Since you are creating a
NimPlayerusingcreatePlayer, make the following constructorprivateand also create a private no-arg constructor so that there is no other way than usingcreatePlayerto create aNimPlayer.
Change it to:
private NimPlayer(String userName, String surName, String givenName) {
this.userName = userName;
this.familyName = surName;
this.givenName = givenName;
}
- Remove the parameters,
int gamePlayedandint scorefromcreatePlayerbecause when you create aNimPlayer, the player does not have any data forgamePlayedandscore. These things will be set during the course of game.
Change it to:
public static void createPlayer(String userName, String familyName, String givenName) {
if (id<10) {
playerList[id++] = new NimPlayer(userName, familyName, givenName);
} else {
System.out.println("Cannot add more players.");
}
}
- Since
scoreandgamePlayedbelong to individual players i.e. each individual player will have his/herscoreandgamePlayedindependent from those of other players, these attributes need to be non-static. You should create astaticvariable only when the value of the variable is supposed to be same for all instances e.g.NimPlayer[] playerListorid. Note that I had asked you earlier to use the name,counterinstead ofidbecause it is supposed to be a counter for the no. of players and therefore the name,idis confusing. If you want to create anidfield for individual players, use theReplace Allfeature of your IDE to replace all occurances ofidwithcounter, all occurances ofIdwithCounter(for replacing getters and setters) and then create a non-staticprivate int id;likefirstName,familyNameetc. insideNimPlayer.
Declare score and gamePlayed as follows:
private int score;
private int gamePlayed;
//public getters and setters of score and gamePlayed
scoreandgamePlayedshould be accessed the way you are accessing names
if (commandin.equals("displayplayer")) {
String user = in.nextLine().trim();
NimPlayer [] players = NimPlayer.getPlayer();
for (int i = 0; i < NimPlayer.getId(); i++) {
String userCheck = players[i].getUserName().trim();
String userName = players[i].getUserName();
String familyName = players[i].getFamilyName();
String givenName = players[i].getGivenName();
int score = players[i].getScore();
int gamePlayed = players[i].getGamePlayed();
if (user != null && userCheck.equals(user)) {
System.out.println(userName + "," + familyName + "," + givenName + "," + gamePlayed + " games,"
+ score + " wins");
}
}
}
- The value of
scoreshould be set as
public static int earnPoint(String player) {
int i = 0;
for (i = 0; i < NimPlayer.getCounter(); i++) {
String playerCheck = NimPlayer.getPlayer()[i].getUserName();
if (playerCheck.equals(player)) {
NimPlayer.getPlayer()[i].setScore(NimPlayer.getPlayer()[i].getScore() + 1);
break;
}
}
return NimPlayer.getPlayer()[i].getScore();
}
回答2:
I completely reworked your model code, which made the rest of the code simpler. Creating a good application model makes creating the rest of the application much easier.
Here's your reworked NimPlayer class. The fields that make up this class all have to do with a game player.
The class consists solely of getters and setters. Two of the setters add instead of replace. There are no static fields in this class.
public class NimPlayer {
private final int id;
private final String userName;
private String familyName;
private String givenName;
private int gamesPlayed;
private int gamesWon;
public NimPlayer(int id, String userName, String familyName,
String givenName) {
this.id = id;
this.userName = userName;
this.familyName = familyName;
this.givenName = givenName;
this.gamesPlayed = 0;
this.gamesWon = 0;
}
public int getId() {
return id;
}
public String getUserName() {
return userName;
}
public String getFamilyName() {
return familyName;
}
public void setFamilyName(String familyName) {
this.familyName = familyName;
}
public String getGivenName() {
return givenName;
}
public void setGivenName(String givenName) {
this.givenName = givenName;
}
public int getGamesPlayed() {
return gamesPlayed;
}
public void addGamePlayed() {
this.gamesPlayed++;
}
public int getGamesWon() {
return gamesWon;
}
public void addGamesWon() {
this.gamesWon++;
}
}
I created a new class, NimModel to hold the state of the game. This class is where the playerList, and all the code associated with the playerList, resides.
Making playerList a List would have simplified the code, but I left playerList as an array to show you the code involved in adding and removing players from an array.
public class NimModel {
private int numberOfPlayers;
private int limit;
private NimPlayer[] playerList;
public NimModel() {
this.numberOfPlayers = 0;
this.limit = 10;
this.playerList = new NimPlayer[limit];
}
public boolean createPlayer(String userName, String familyName,
String givenName) {
if (numberOfPlayers < limit) {
int id = getFirstPlayerSlot();
if (id >= 0) {
playerList[id] = new NimPlayer(id,
userName, familyName, givenName);
numberOfPlayers++;
}
return true;
} else {
return false;
}
}
private int getFirstPlayerSlot() {
for (int i = 0; i < limit; i++) {
if (playerList == null) {
return i;
}
}
return -1;
}
public NimPlayer getPlayer(int id) {
return playerList[id];
}
public NimPlayer getPlayer(String userName) {
for (int i = 0; i < limit; i++) {
if (playerList[i] != null) {
if (userName.equals(playerList[i].getUserName())) {
return playerList[i];
}
}
}
return null;
}
public NimPlayer removePlayer(String userName) {
for (int i = 0; i < limit; i++) {
NimPlayer player = playerList[i];
if (player != null) {
if (userName.equals(player.getUserName())) {
this.playerList[i] = null;
numberOfPlayers--;
return player;
}
}
}
return null;
}
public int getNumberOfPlayers() {
return numberOfPlayers;
}
}
Finally, here are your reworked Nimsys and NimGame classes. Again, we've removed all of the static references.
It makes code a lost easier to read and understand if you code methods in the order that they're called. In other words, present the main points first, then the details.
import java.util.Scanner;
public class Nimsys {
private NimModel nimModel;
public static void main(String[] args) {
Nimsys nimsys = new Nimsys();
nimsys.processCommands();
}
private void processCommands() {
this.nimModel = new NimModel();
Scanner in = new Scanner(System.in);
while (true) {
System.out.print('$');
String commandin = in.nextLine().trim();
if (commandin.equalsIgnoreCase("addplayer")) {
addPlayer(in);
}
if (commandin.equalsIgnoreCase("removeplayer")) {
removePlayer(in);
}
if (commandin.equalsIgnoreCase("editplayer")) {
editPlayer(in);
}
if (commandin.equalsIgnoreCase("displayplayer")) {
displayPlayer(in);
}
if (commandin.equalsIgnoreCase("startgame")) {
startGame(in);
}
}
}
private void addPlayer(Scanner in) {
String inName = in.nextLine().trim();
String[] name = splitName(inName);
if (name != null && name.length == 3) {
NimPlayer player = nimModel.getPlayer(name[0]);
if (player == null) {
nimModel.createPlayer(name[0], name[1], name[2]);
System.out.println("The player has been created.");
} else {
System.out.println("The player is already in "
+ "the list.");
}
} else {
System.out.println("Not Valid! Please enter again!");
}
}
private String[] splitName(String inName) {
String[] splittedLine = inName.split(",");
String[] name = null;
if (splittedLine.length == 3) {
String userName = splittedLine[0].trim();
String familyName = splittedLine[1].trim();
String givenName = splittedLine[2].trim();
name = new String[3];
name[0] = userName;
name[1] = familyName;
name[2] = givenName;
}
return name;
}
private void removePlayer(Scanner in) {
String removeUserName = in.nextLine().trim();
NimPlayer player = nimModel.removePlayer(removeUserName);
if (player == null) {
System.out.println("The player does not exist");
} else {
System.out.println("Player " + player.getUserName() +
" removed successfully!");
}
}
private void editPlayer(Scanner in) {
String inName = in.nextLine().trim();
String[] splittedLine = inName.split(",");
if (splittedLine != null && splittedLine.length == 3) {
String userName = splittedLine[0].trim();
String familyName = splittedLine[1].trim();
String givenName = splittedLine[2].trim();
NimPlayer player = nimModel.getPlayer(userName);
if (player == null) {
System.out.println("The player does "
+ "not exist.");
} else {
player.setFamilyName(familyName);
player.setGivenName(givenName);
System.out.println("Edited successfully");
}
} else {
System.out.println("Invalid user name! Please "
+ "enter again.");
}
}
private void displayPlayer(Scanner in) {
String userName = in.nextLine().trim();
NimPlayer player = nimModel.getPlayer(userName);
String familyName = player.getFamilyName();
String givenName = player.getGivenName();
int gamesWon = player.getGamesWon();
int gamesPlayed = player.getGamesPlayed();
System.out.println(userName + "," + familyName +
"," + givenName + "," + gamesPlayed +
" games," + gamesWon + " wins");
}
private void startGame(Scanner in) {
NimPlayer player1 = null, player2 = null;
do {
String dataIn = in.nextLine().trim();
String[] data = splitData(dataIn);
if (data != null && data.length == 4) {
player1 = nimModel.getPlayer(data[2]);
player2 = nimModel.getPlayer(data[3]);
NimGame game = new NimGame(nimModel, data[0],
data[1], player1, player2);
game.playGame();
}
} while (player1 == null || player2 == null);
}
private String[] splitData(String dataIn) {
String[] splittedLine = dataIn.split(",");
String[] data = null;
if (splittedLine.length == 4) {
String initialStone = splittedLine[0];
String stoneRemoval = splittedLine[1];
String player1 = splittedLine[2].trim();
String player2 = splittedLine[3].trim();
data = new String[4];
data[0] = initialStone;
data[1] = stoneRemoval;
data[2] = player1;
data[3] = player2;
}
return data;
}
}
NimGame class
import java.util.Scanner;
public class NimGame {
NimPlayer player1;
NimPlayer player2;
String playOrNot;
String initialStoneInput;
String dataRemoval;
int stars;
int stoneBalance;
int initialStone;
int upperBound;
public NimGame(NimModel nimModel, String initialStoneInput,
String dataRemoval,
NimPlayer player1, NimPlayer player2) {
this.initialStoneInput = initialStoneInput;
this.dataRemoval = dataRemoval;
this.player1 = player1;
this.player2 = player2;
}
Scanner in = new Scanner(System.in);
public void playGame() {
// Convert user input string into integer
int initialStoneInt = Integer.parseInt(initialStoneInput);
initializeStone(initialStoneInt);
int upperBound = Integer.parseInt(dataRemoval);
System.out.println("Initial stone count: " +
initialStoneInt);
System.out.println("Maximum stone removal: " +
dataRemoval);
System.out.println("Player 1: " + player1.getUserName());
System.out.println("Player 2: " + player2.getUserName());
do {
// while stoneBalance > 0, two players
// keep playing the game
while (stoneBalance > 0) {
// player1's turn and remove the stones;
// decision of winning
System.out.println(player1.getUserName() + "'s "
+ "turn - remove how many?\n");
int takeStone = in.nextInt();
while (takeStone > upperBound ||
takeStone <= 0) {
System.out.println("Invalid, you need "
+ "to remove stones under upper "
+ "bound limit or above 0. \n"
+ "Please enter again.");
takeStone = in.nextInt();
}
removeStones(takeStone); // remove the stone
if (stoneBalance > 0) {
// show the remaining stones
System.out.print(stoneBalance +
" stones left:");
printStar(stoneBalance);
} else if (stoneBalance <= 0) {
System.out.println("Game Over\n" +
player2.getUserName() + " wins!\n");
earnPoint(player2);
break;
}
// player2's turn and remove the stones;
// decision of winning
System.out.println(player2.getUserName() + "'s "
+ "turn - remove how many?\n");
takeStone = in.nextInt();
while (takeStone > upperBound ||
takeStone <= 0) {
System.out.println("Invalid, you need "
+ "to remove stones under upper "
+ "bound limit or above 0. \n"
+ "Please enter again.");
takeStone = in.nextInt();
}
removeStones(takeStone);
if (stoneBalance > 0) {
System.out.print(stoneBalance + " "
+ "stones left:");
printStar(stoneBalance);
} else if (stoneBalance <= 0) {
System.out.println("Game Over\n" +
player1.getUserName() + " wins!\n");
earnPoint(player1);
break;
}
}
player1.addGamePlayed();
player2.addGamePlayed();;
// ask players to play again
// in.nextLine();
System.out.println("Do you want to play "
+ "again (Y/N):");
playOrNot = in.nextLine().trim();
} while (playOrNot.equalsIgnoreCase("Y"));
}
public int initializeStone(int startStones) {
stoneBalance = startStones;
return stoneBalance;
}
public void removeStones(int stonesTaken) {
int updatedBalance = stoneBalance - stonesTaken;
stoneBalance = updatedBalance;
}
private void printStar(int star) {
stars = star;
stars = stoneBalance;
for (int stars = 1; stars <= star; stars++) {
System.out.print(" *");
}
System.out.println();
}
private int earnPoint(NimPlayer player) {
player.addGamesWon();
return player.getGamesWon();
}
}
来源：https://stackoverflow.com/questions/61319532/how-to-pass-values-using-setter-and-getter-among-three-classes