我不是java的专家,在我的Snake游戏中遇到了一个问题。我创建了一个名为GameManager的类:
public class GameManager {
private GameObject board[][];
private int xR;
private int yR;
public Snake snk;
private Food food;
public GameManager (String fileName) {
BufferedReader fileInput = null;
try {
fileInput = new BufferedReader(new FileReader(fileName));
Scanner fileScanner = new Scanner(fileInput);
int rows = fileScanner.nextInt();
int cols = fileScanner.nextInt();
board = new GameObject[rows][cols];
for (int row = 0; row < rows; row++) {
for (int col = 0; col < cols; col++) {
board[row][col] = new Empty();
}
}
while(fileScanner.hasNext()) {
fileScanner.nextLine();
int xStart = fileScanner.nextInt();
int yStart = fileScanner.nextInt();
int xEnd = fileScanner.nextInt();
int yEnd = fileScanner.nextInt();
addWall(xStart, yStart, xEnd, yEnd);
}
addGameObject(snk);
addGameObject(food);
fileScanner.close();
} catch(IOException e) {
e.printStackTrace();
} finally {
try {
if(fileInput != null) {fileInput.close();}
} catch(IOException e) {
e.printStackTrace();
}
}
}
public void newRandomXY() {
Random r = new Random(0);
this.xR = r.nextInt(board.length);
this.yR = r.nextInt(board.length);
}
public void addGameObject(GameObject s) {
newRandomXY();
while(board[xR][yR].isOccupied()) {
newRandomXY();
}
if(s instanceof Snake) {
s = new Snake(xR, yR);
board[xR][yR] = s;
} else if(s instanceof Food) {
s = new Food(xR, yR);
board[xR][yR] = s;
}
}
public void addWall(int xStart, int yStart, int xEnd, int yEnd) {
for(int x = xStart; x <= xEnd; x++) {
for(int y = yStart; y <= yEnd; y++) {
board[x][y] = new Wall();
}
}
}
@Override
public String toString() {
String ret = "";
for (int row = 0; row < board.length; row++) {
for (int col = 0; col < board[row].length; col++) {
ret += board[row][col].toString();
}
ret += "\n";
}
return ret;
}
}
现在我遇到的问题是,每当我尝试在我的cmd上打印此板的字符串版本时,程序就会挂起,我必须努力关闭cmd。我一直在搞乱一些代码而且我已经能够修复程序崩溃了,但是我还没弄清楚为什么它都没有打印出来。
这是我的Snake类(注意:我此类中还有其他一些方法,我目前还没有使用,所以我不认为它们是问题):
public class Snake extends GameObject {
private Point head;
private Deque<Point> snakeBody;
private int lenght = 0;
private String direction = "UP";
public Snake(int x, int y) {
this.head = super.newCell(x, y);
this.snakeBody = new ArrayDeque<Point>();
this.snakeBody.push(head);
}
和我的toString of Snake:
public String toString(Deque<Point> s) {
String str = "";
for(Point p : s) {
String snk = p.toString();
snk = "S";
str += snk;
}
return str;
}
这是我的食品类:
public class Food extends GameObject {
private Point foodLoc;
public Food(int x, int y) {
this.foodLoc = new Point(x, y);
}
public Point getLocation() {
return foodLoc.getLocation();
}
public String toString() {
return "F";
}
}
这是我的GameObject类:
import java.awt.Point;
public class GameObject {
public final int CELL_SIZE = 1;
public Point newCell(int x, int y) {
return new Point(x, y);
}
public boolean isOccupied() {
return true;
}
public boolean isOccupied(Point p, Point o) {
boolean flag = false;
if(p.getLocation().equals(o.getLocation())) {
flag = true;
} else {
flag = false;
}
return flag;
}
}
我很清楚我在Snake中的toString方法是完全错误的,但我不一定了解如何修复它以及为什么我的其他toString方法不起作用。我浏览了论坛,看看能否找到并回答,但我找不到任何相关内容。
答案 0 :(得分:0)
问题是你正在尝试打印gameObject类型的数组,但是该对象没有.toString运算符,所以它总是返回null。
我猜你想要将单元格表示为空或被占用,或者甚至可能通过食物进一步表示,但是你需要在该类中使用.toString来定义你想要在任何给定场景中返回的内容。