我的目标是使用堆栈穿越迷宫，但我无法走得很远。
我有一个二维Room对象数组，我总是从位置 1,1 开始。我相信我已经正确设置了一切。但是，NullPointerException每当我尝试访问存储在我的数组中的数据时，我都会得到一个。
任何可以为我指明正确方向的帮助将不胜感激。
这是我的房间类：
import java.awt.Point;
public class Room {
private Room up;
private Room down;
private Room left;
private Room right;
private char value;
private boolean blocked;
private boolean visited = false;
private Point p;
public void setCord(int row, int column) {
p = new Point(row, column);
}
public void setUp(Room [][] r, int row, int column) {
up = r[row][column];
}
public void setDown(Room[][] r, int row, int column) {
down = r[row][column];
}
public void setRight(Room[][] r, int row, int column) {
right = r[row][column];
}
public void setLeft(Room[][] r, int row, int column) {
left = r[row][column];
}
public void setValue(char c) {
value = c;
}
public void setVisited(boolean b) {
visited = b;
}
public void setBlocked(boolean b) {
blocked = b;
}
public Point getCord() {
return p;
}
public Room getUp() {
return up;
}
public Room getDown() {
return down;
}
public Room getRight() {
return right;
}
public Room getLeft() {
return left;
}
public char getValue() {
return value;
}
public boolean getVisited() {
return visited;
}
public boolean getBlocked() {
return blocked;
}
}
这是我的迷宫课：
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.*;
import javax.swing.JOptionPane;
public class Maze {
String inFile, // Name of file to be used as input
outFile, // Name of file to output completed maze to
line; // Current line being read by scanner
char [][] mazeContent;
Room [][] rooms;// Holds the values that create maze
Room [] theStack;
Room current = new Room();
ArrayList<Room> al;
int rows, columns;
int tos = 0;
char [][] mazeC;
public static void main(String []args) throws Exception {
Maze m = new Maze();
}
public Maze() throws FileNotFoundException {
// Prompts user for the name of the file they wish to use as the input file.
inFile = JOptionPane.showInputDialog(null, "Please enter the name of the file you wish to read, including " +
"the file path:");
//if(inFile.equals("")) inFile = "C:\Java\JavaFiles\maze1.txt;
// Prompts user to enter the name they wish to save the file under.
outFile = JOptionPane.showInputDialog(null, "Please enter the filename you wish to save the data to:");
// Creates a scanner object to read in the input file.
Scanner readFile = new Scanner(new FileReader(inFile));
PrintWriter output = new PrintWriter(outFile);
rows = readFile.nextInt();
columns = readFile.nextInt();
readFile.nextLine();
theStack = new Room[1000];
mazeContent = new char [rows][columns];
rooms = new Room [rows][columns];
theStack = new Room[1000];
for(int i = 0; i < rows; i++) {
line = readFile.nextLine();
for(int j = 0; j< line.length(); j++) {
mazeContent[i][j] = line.charAt(j);
}
}
createRooms();
findPath();
}
private void findPath() {
Room start = rooms[1][1];
push(start);
while(!isEmpty()) {
current = pop();
//System.out.println("The value is " + current.getValue());
if(current.getValue() == '$') {
System.out.println("Success");
}
else if(current.getBlocked() != true && current.getVisited() != true) {
current.setVisited(true);
push(current.getRight());
push(current.getLeft());
push(current.getUp());
push(current.getDown());
}
}
}
public void createRooms() {
for(int i = 1; i < rows - 1; i++) {
for(int j = 1; j < columns -1; j++) {
Room r = new Room();
r.setCord(i,j);
r.setValue(mazeContent[i][j]);
r.setUp(rooms, i-1, j);
r.setDown(rooms, i+1, j);
r.setRight(rooms, i, j+1);
r.setLeft(rooms, i, j-1);
if(mazeContent[i][j] == '*')
r.setBlocked(true);
else
r.setBlocked(false);
rooms[i][j] = r;
}
}
}
private Room pop() {
return theStack[--tos];
}
private boolean isEmpty() {
// TODO Auto-generated method stub
return tos == 0;
}
private void push(Room item) {
if (isFull()) {
System.out.println("The stack is full!");
}
else
theStack[tos++] = item;
}
private boolean isFull() {
return tos == theStack.length-1;
}
}