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Help me to run this program
Hello people,
I found a program on internet that reads 2 text files "maze.txt" and "randomMaze.txt" in which we can find *, space, S (for start) and E (for end). It resolves this maze by using DFS algorithm.
My problem is that it does not run, it says there is a NullPoint exception error. Can you fix for me the problem please ? Here is the code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.util.Random;
class Maze extends JFrame
{
public static void main(String args[])
{
Maze f= new Maze();
f.setBounds(150,50,500,500);
f.setVisible(true);
}
int maze[][]; //save the maze
Point mouse=new Point(); //the position of the mouse
jpMainPanel mp=new jpMainPanel(); //the firstMaze panel
jpRandomPanel rp=new jpRandomPanel(); //the randomMaze panel
JButton jbDFS=new JButton("DFS"); //the Buttons
JButton jbBFS=new JButton("BFS");
JButton jbASTAR=new JButton("A*");
JButton jbNewState=new JButton("New State");
JButton jbIDS=new JButton("IDS");
JLabel jlPart1=new JLabel("Part I"); //the Labels
JLabel jlPart2=new JLabel("Part II");
Random rand;
public Maze() //the constructor of maze class
{
super("AI assignment");
JPanel jpCtrlBar=new JPanel(); //GUI setting
jpCtrlBar.setLayout(new FlowLayout());
jpCtrlBar.add(jlPart1);
jpCtrlBar.add(jbDFS);
jpCtrlBar.add(jbBFS);
jpCtrlBar.add(jbASTAR);
jpCtrlBar.add(jlPart2);
jpCtrlBar.add(jbNewState);
jpCtrlBar.add(jbIDS);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(mp, BorderLayout.CENTER);
getContentPane().add(jpCtrlBar, BorderLayout.SOUTH);
mp.setBackground(Color.WHITE);
//set the listener
this.addWindowListener(
new WindowAdapter(){
public void windowClosing(WindowEvent evt) {
mp=null;
System.exit(0);
}
}
);
jbBFS.addActionListener(
new ActionListener()
{ public void actionPerformed(ActionEvent event)
{ jbBFSActionPerformed(event);
}
}
);
jbDFS.addActionListener(
new ActionListener()
{ public void actionPerformed(ActionEvent event)
{ jbDFSActionPerformed(event);
}
}
);
jbASTAR.addActionListener(
new ActionListener()
{ public void actionPerformed(ActionEvent event)
{ jbASTARActionPerformed(event);
}
}
);
jbIDS.addActionListener(
new ActionListener()
{ public void actionPerformed(ActionEvent event)
{ jbIDSActionPerformed(event);
}
}
);
jbNewState.addActionListener(
new ActionListener()
{ public void actionPerformed(ActionEvent event)
{ jbNewStateActionPerformed(event);
}
}
);
initGame();
}
public void initGame() //load firstMaze
{
getMaze();
getContentPane().add(mp, BorderLayout.CENTER);
mp.setMaze(maze);
mp.setMouse(mouse);
jbDFS.setEnabled(true);
jbBFS.setEnabled(true);
jbASTAR.setEnabled(true);
jbIDS.setEnabled(true);
jbNewState.setEnabled(true);
mp.setVisible(true);
rp.setVisible(false);
mp.repaint();
}
public void initRandomGame() //load second random Maze
{ getRandomMaze();
getContentPane().add(rp, BorderLayout.CENTER);
rp.setBackground(Color.WHITE);
rp.setMaze(maze);
rp.setMouse(mouse);
jbDFS.setEnabled(true);
jbBFS.setEnabled(true);
jbASTAR.setEnabled(true);
jbIDS.setEnabled(true);
jbNewState.setEnabled(true);
rp.repaint();
}
public void getMaze() //get the maze from the text file
{
String s[]=new String[20];
int line_num=0;
try{
BufferedReader br=new BufferedReader(new FileReader("maze.txt"));
for (int i=0;i<s.length;i++){
s[i]=br.readLine();
if (s[i] !=null)
line_num++;
else break;
}
}catch (Exception e){}
maze=new int[line_num+2][s[0].length()+2];
for (int i=0; i<maze.length; i++)
for (int j=0; j<maze[0].length; j++)
{
if (i==0 || i==line_num+1)
maze[i][j]=1; //up and down
else if (j==0 || j==s[0].length()+1)
maze[i][j]=1; //right and left
else if (s[i-1].charAt(j-1)=='*')
maze[i][j]=1; //wall
else if (s[i-1].charAt(j-1)=='S'){ //starter
mouse.setLocation(j,i);
maze[i][j]=10;
}
else if (s[i-1].charAt(j-1)=='E')
maze[i][j]=11; //end
else maze[i][j]=0; //road
}
}
public void getRandomMaze() //get maze from another text file
{ String s[]=new String[20];
int line_num=0;
Random rand = new Random();
int n =0, m=0;
try{
BufferedReader br=new BufferedReader(new FileReader("randomMaze.txt"));
for (int i=0;i<s.length;i++){
s[i]=br.readLine();
if (s[i] !=null)
line_num++;
else break;
}
}catch (Exception e){}
maze=new int[line_num+2][s[0].length()+2];
for (int i=0; i<maze.length; i++)
for (int j=0; j<maze[0].length; j++)
{
if (i==0 || i==line_num+1)
maze[i][j]=1; //up and down
else if (j==0 || j==s[0].length()+1)
maze[i][j]=1; //right and left
else if (s[i-1].charAt(j-1)=='*')
maze[i][j]=1; //wall
//else if (s[i-1].charAt(j-1)=='S'){ //starter
// mouse.setLocation(j,i);
// maze[i][j]=10;
//}
//else if (s[i-1].charAt(j-1)=='E')
// maze[i][j]=11; //end
else maze[i][j]=0; //road
}
do{
m = rand.nextInt(10);
n = rand.nextInt(10);
//System.out.println(m+1);
//System.out.println(n+1);
}
while (s[m].charAt(n)=='*' || s[n].charAt(m)=='*');
mouse.setLocation(n+1,m+1);
maze[m+1][n+1]=10;
do{
m = rand.nextInt(10);
n = rand.nextInt(10);
//System.out.println(m+1);
//System.out.println(n+1);
}
while (s[m].charAt(n)=='*' || s[n].charAt(m)=='*');
maze[m+1][n+1]=11;
}
public void jbDFSActionPerformed(ActionEvent event)
{ initGame();
DepthFirstSearch dfs=new DepthFirstSearch();
jbDFS.setEnabled(false);
jbBFS.setEnabled(false);
jbASTAR.setEnabled(false);
jbIDS.setEnabled(false);
jbNewState.setEnabled(false);
dfs.start();
}
public void jbBFSActionPerformed(ActionEvent event)
{ initGame();
BreadthFirstSearch bfs=new BreadthFirstSearch();
jbDFS.setEnabled(false);
jbBFS.setEnabled(false);
jbASTAR.setEnabled(false);
jbIDS.setEnabled(false);
jbNewState.setEnabled(false);;
bfs.start();
}
public void jbASTARActionPerformed(ActionEvent event)
{ initGame();
ASTAR astar=new ASTAR();
jbDFS.setEnabled(false);
jbBFS.setEnabled(false);
jbASTAR.setEnabled(false);
jbIDS.setEnabled(false);
jbNewState.setEnabled(false);
astar.start();
}
public void jbIDSActionPerformed(ActionEvent event)
{ IterativeDeepSearch ids=new IterativeDeepSearch();
jbDFS.setEnabled(false);
jbBFS.setEnabled(false);
jbASTAR.setEnabled(false);
jbIDS.setEnabled(false);
jbNewState.setEnabled(false);
ids.start();
}
public void jbNewStateActionPerformed(ActionEvent event)
{ NewState newstate=new NewState();
mp.setVisible(false);
initRandomGame();
rp.setVisible(true);
jbDFS.setEnabled(false);
jbBFS.setEnabled(false);
jbASTAR.setEnabled(false);
jbIDS.setEnabled(false);
jbNewState.setEnabled(false);
newstate.start();
}
class BreadthFirstSearch extends Thread //BFS class
{
public void run()
{ findExit();
}
public boolean findExit()
{ //till the end
if (maze[mouse.y][mouse.x]==11){
JOptionPane.showMessageDialog((Component)null," ^-^ Reach the goal","Game Over",JOptionPane.INFORMATION_MESSAGE);
initGame();
return true;
}
maze[mouse.y][mouse.x]=50; //mark has visited
//delay
try{
Thread.sleep(500);
}
catch (Exception e){}
//right
if (step(1,0))
if (findExit()==true)
return true;
else mouse.x--;
up
if (step(0,-1))
if (findExit()==true)
return true;
else mouse.y++;
//down
if (step(0,1))
if (findExit()==true)
return true;
else mouse.y--;
//can not find the exit
maze[mouse.y][mouse.x]=51; //mark it is not through
return false;
}
public boolean step(int x,int y)
{
int target=maze[mouse.y+y][mouse.x+x];
if (target ==0 || target ==11 || target ==10){
mouse.x+=x;
mouse.y+=y;
repaint();
return true;
}
else
return false;
}
}
class DepthFirstSearch extends Thread //DFS class
{
public void run()
{
findExit();
}
public boolean findExit()
{
//till the end
if (maze[mouse.y][mouse.x]==11){
JOptionPane.showMessageDialog((Component)null," ^-^ Reach the goal","Game Over",JOptionPane.INFORMATION_MESSAGE);
initGame();
return true;
}
maze[mouse.y][mouse.x]=50; //mark has visited
//delay
try{
Thread.sleep(500);
}
catch (Exception e){}
//down
if (step(0,1))
if (findExit()==true)
return true;
else mouse.y--;
//right
if (step(1,0))
if (findExit()==true)
return true;
else mouse.x--;
//can not find the exit
maze[mouse.y][mouse.x]=51; //mark it is not through
return false;
}
public boolean step(int x,int y)
{
int target=maze[mouse.y+y][mouse.x+x];
if (target ==0 || target ==11 || target ==10){
mouse.x+=x;
mouse.y+=y;
repaint();
return true;
}
else
return false;
}
}
class IterativeDeepSearch extends Thread //IDS class
{
public void run()
{
findExit();
}
public boolean findExit()
{
//till the end
if (maze[mouse.y][mouse.x]==11){
JOptionPane.showMessageDialog((Component)null," ^-^ Reach the goal","Game Over",JOptionPane.INFORMATION_MESSAGE);
initRandomGame();
return true;
}
maze[mouse.y][mouse.x]=50; //mark has visited
//delay
try{
Thread.sleep(500);
}
catch (Exception e){}
//left
if (step(-1,0))
if (findExit()==true)
return true;
else mouse.x++;
//right
if (step(1,0))
if (findExit()==true)
return true;
else mouse.x--;
//up
if (step(0,-1))
if (findExit()==true)
return true;
else mouse.y++;
//down
if (step(0,1))
if (findExit()==true)
return true;
else mouse.y--;
//can not find the exit
maze[mouse.y][mouse.x]=51; //mark it is not through
return false;
}
public boolean step(int x,int y)
{
int target=maze[mouse.y+y][mouse.x+x];
if (target ==0 || target ==11 || target ==10){
mouse.x+=x;
mouse.y+=y;
repaint();
return true;
}
else
return false;
}
}
class ASTAR extends Thread //A* search class
{
public void run()
{ findExit();
}
public boolean findExit()
{ //till the end
if (maze[mouse.y][mouse.x]==11){
JOptionPane.showMessageDialog((Component)null," ^-^ Reach the goal","Game Over",JOptionPane.INFORMATION_MESSAGE);
initGame();
return true;
}
maze[mouse.y][mouse.x]=50; //mark has visited
//delay
try{
Thread.sleep(500);
}
catch (Exception e){}
//right
if (step(1,0))
if (findExit()==true)
return true;
else mouse.x--;
//down
if (step(0,1))
if (findExit()==true)
return true;
else mouse.y--;
//can not find the exit
maze[mouse.y][mouse.x]=51; //mark it is not through
return false;
}
public boolean step(int x,int y)
{
int target=maze[mouse.y+y][mouse.x+x];
if (target ==0 || target ==11 || target ==10){
mouse.x+=x;
mouse.y+=y;
repaint();
return true;
}
else
return false;
}
}
class NewState extends Thread //get a new state and implement a DFS
{
public void run()
{
findExit();
}
public boolean findExit()
{ //till the end
if (maze[mouse.y][mouse.x]==11){
JOptionPane.showMessageDialog((Component)null," ^-^ Reach the goal","Game Over",JOptionPane.INFORMATION_MESSAGE);
initRandomGame();
return true;
}
maze[mouse.y][mouse.x]=50; //mark has visited
//delay
try{
Thread.sleep(500);
}
catch (Exception e){}
//down
if (step(0,1))
if (findExit()==true)
return true;
else mouse.y--;
//right
if (step(1,0))
if (findExit()==true)
return true;
else mouse.x--;
//left
if (step(-1,0))
if (findExit()==true)
return true;
else mouse.x++;
//up
if (step(0,-1))
if (findExit()==true)
return true;
else mouse.y++;
//can not find the exit
maze[mouse.y][mouse.x]=51; //mark it is not through
return false;
}
public boolean step(int x,int y)
{
int target=maze[mouse.y+y][mouse.x+x];
if (target ==0 || target ==11 || target ==10){
mouse.x+=x;
mouse.y+=y;
repaint();
return true;
}
else
return false;
}
}
class jpMainPanel extends JPanel //the first Maze panel
{
int maze[][];
Point mouse;
///let the main draw gui program get the maze setting
public void setMaze(int arry[][])
{
this.maze=arry;
}
///let the main draw gui program get the mouse position
public void setMouse(Point arg)
{
mouse=arg;
}
///main draw gui program
public void paintComponent(Graphics g)
{
super.paintComponent(g);
int stuff=100;
//draw the maze
for (int i=1;i<maze.length-1;i++)
for (int j=1;j<maze[i].length-1;j++){
if (maze[i][j]==1){
//wall
g.drawString("*",j*20+stuff,i*20+stuff);
}
else if (maze[i][j]==0){
//road
}
else if (maze[i][j]==10){
//starter
}
else if (maze[i][j]==11){
//end
g.setColor(new Color(0,255,0));
g.drawString("O",j*20+stuff,i*20+stuff);
g.setColor(new Color(0,0,0));
}
else{}
}
//draw the position of the mouse
g.setColor(new Color(0,0,255));
g.drawString("O",mouse.x*20+stuff,mouse.y*20+stuff);
g.setColor(new Color(0,0,0));
}
}
class jpRandomPanel extends JPanel //the second maze panel
{
int maze[][];
Point mouse;
///let the main draw gui program get the maze setting
public void setMaze(int arry[][])
{
this.maze=arry;
}
///let the main draw gui program get the mouse position
public void setMouse(Point arg)
{
mouse=arg;
}
///main draw gui program
public void paintComponent(Graphics g)
{
super.paintComponent(g);
int stuff=100;
//draw the maze
for (int i=1;i<maze.length-1;i++)
for (int j=1;j<maze[i].length-1;j++){
if (maze[i][j]==1){
//wall
g.drawString("*",j*20+stuff,i*20+stuff);
}
else if (maze[i][j]==0){
//road
}
else if (maze[i][j]==10){
//starter
}
else if (maze[i][j]==11){
//end
g.setColor(new Color(0,255,0));
g.drawString("O",j*20+stuff,i*20+stuff);
g.setColor(new Color(0,0,0));
}
else{}
}
//draw the position of the mouse
g.setColor(new Color(0,0,255));
g.drawString("O",mouse.x*20+stuff,mouse.y*20+stuff);
g.setColor(new Color(0,0,0));
}
}
}Here's how to copy from the command prompt console:
To copy the contents of the command prompt window:
Click on Icon in upper left corner
Select Edit
Select 'Select All' - The selection will show
Click in upper left again
Select Edit and click 'Copy'
Paste here.
NormR1
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