helo, can any one help to read one class from another class. i em knew with java actually. i got class a which has got sub class b static class. now i em trying to access class a from another class c using button. when in class c user click on button class a should load. is there any one there to help.... thank you in advance
Emint

emint,

Don't say "thank you in advance", we have to talk more yet.
I think you want to create an object of class A.

A.java

C.java

Thank you for your reply. yes i did what you said. it works but i got program as i told you earlier class A has got sub class B as static when i run them they works fine. but wen i try to from class c it give an error. i dun know where i m makin mistake. i m attachin my code here. you can have look.

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import javax.swing.*;




public class Maze extends JFrame
{
public static String a, b, c;
public static final int TILE_SIZE = 20;

public Maze()
{
// super("Maze algorithm program");


RunDB runDB = new RunDB();

try{
runDB.loadDriver();
runDB.makeConnection();
runDB.buildStatement();
runDB.executeQuery();
String x;
x = runDB.text;
c = x.substring(6, 9);
b = x.substring(3, 6);
a = x.substring(0, 3);

}catch(Exception e){
e.printStackTrace();
}



}

String maze = a+b+c;


int width = (int)Math.sqrt(maze.length());

Screen screen;

void searchExit(Screen screen, int milliseconds) {
this.screen = screen;
int[] startCoordinates = getCoordinates(maze.indexOf("S"));
maze = visit(maze, startCoordinates[0], startCoordinates[1]);
}

String visit(String maze, int x, int y) {
screen.showMaze(maze,0);
if (foundExit(maze))
return maze;

if (isEmpty(maze, x - 1, y)) {
String newMaze = moveLeft(maze, x, y);
String visitedNewMaze = visit(newMaze, x - 1, y);
if (foundExit(visitedNewMaze))
return visitedNewMaze;
}
if (isEmpty(maze, x, y - 1)) {
String newMaze = moveUp(maze, x, y);
String visitedNewMaze = visit(newMaze, x, y - 1);
if (foundExit(visitedNewMaze))
return visitedNewMaze;
}
if (isEmpty(maze, x + 1, y)) {
String newMaze = moveRight(maze, x, y);
String visitedNewMaze = visit(newMaze, x + 1, y);
if (foundExit(visitedNewMaze))
return visitedNewMaze;
}
if (isEmpty(maze, x, y + 1)) {
String newMaze = moveDown(maze, x, y);
String visitedNewMaze = visit(newMaze, x, y + 1);
if (foundExit(visitedNewMaze))
return visitedNewMaze;

}
return maze;
}

int[] getCoordinates(int pos) {
return new int[] { pos % width, pos / width };
}

int getPosition(int x, int y) {
return y * width + x;
}

boolean isInsideMaze(String maze, int x, int y) {
if (x < 0 || x >= width)
return false;
if (y < 0 || y >= width)
return false;
int pos = getPosition(x, y);
return pos >= 0 && pos < maze.length();
}

char look(String maze, int x, int y) {
return maze.charAt(getPosition(x, y));
}

boolean isEmpty(String maze, int x, int y) {
if (!isInsideMaze(maze, x, y))
return false;
return look(maze, x, y) == 'P';
}

static int cnt = 0;
boolean isExit(String maze, int x, int y) {
if (!isInsideMaze(maze, x, y))
return false;
return look(maze, x, y) == 'E';
}

boolean isStone(String maze, int x, int y) {
if (!isInsideMaze(maze, x, y))
return false;
return look(maze, x, y) == '.';
}

boolean foundExit(String maze) {
cnt++;
if (cnt % 100 == 0)
System.out.println(cnt);
int[] exitCoordinates = getCoordinates(maze.indexOf('E'));
if (isStone(maze, exitCoordinates[0] - 1, exitCoordinates[1])) {
return true;
}
if (isStone(maze, exitCoordinates[0], exitCoordinates[1] - 1)) {
return true;
}
if (isStone(maze, exitCoordinates[0] + 1, exitCoordinates[1])) {
return true;
}
if (isStone(maze, exitCoordinates[0], exitCoordinates[1] + 1)) {
return true;
}
return false;
}

String setStone(String maze, int x, int y) {
int pos = getPosition(x, y);
return maze.substring(0, pos) + '.'
+ maze.substring(pos + 1, maze.length());
}

String moveUp(String maze, int x, int y) {
return setStone(maze, x, y - 1);
}

String moveDown(String maze, int x, int y) {
return setStone(maze, x, y + 1);
}

String moveLeft(String maze, int x, int y) {
return setStone(maze, x - 1, y);
}

String moveRight(String maze, int x, int y) {
return setStone(maze, x + 1, y);
}

static class Screen extends Maze {

int WIDTH = 500;

String maze = "";

public Screen() {


setSize(500,700 );
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}



public void addComponent(String region, Component component) {
Panel panel = new Panel();
panel.add(component);
add(region, panel); // make sure you add the panel!
}
public void paint(Graphics g) {
BufferedImage image = (BufferedImage) createImage(WIDTH, WIDTH);
Graphics g2 = image.getGraphics();
g2.setColor(Color.GRAY);
g2.fillRect(0, 0, WIDTH, WIDTH);
int n = (int) Math.sqrt(maze.length());
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
char type = maze.charAt(i + j * n);
drawMazeArea(g2, i, j, n, type);
g2.fillRect(i*TILE_SIZE,j*TILE_SIZE,TILE_SIZE,TILE_SIZE);
g.setColor(g.getColor().darker());
g2.drawRect(i*TILE_SIZE,j*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}
}
g.drawImage(image, 0, 0, this);
}

void drawMazeArea(Graphics g, int i, int j, int n, char type) {
if (type == 'O')
{
g.setColor(Color.BLUE);

}
if (type == 'P')
{
g.setColor(Color.WHITE);
g.fillRect('P'*TILE_SIZE,'P'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
//g.setColor(g.getColor().darker());
g.drawRect('P'*TILE_SIZE,'P'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}
if (type == 'S')
{
g.setColor(Color.RED);
g.fillRect('S'*TILE_SIZE,'S'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
//g.setColor(g.getColor().darker());
g.drawRect('S'*TILE_SIZE,'S'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}
if( type == '.')
{
g.setColor(Color.YELLOW);
g.fillRect('.'*TILE_SIZE,'.'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
//g.setColor(g.getColor().darker());
g.drawRect('.'*TILE_SIZE,'.'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}

if (type == 'E')
{
g.setColor(Color.GREEN);
g.fillRect('E'*TILE_SIZE,'E'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
//g.setColor(g.getColor().darker());
g.drawRect('E'*TILE_SIZE,'E'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}
int r = WIDTH / (n + 3);
int x = i * r + r, y = j * r + r, width = r, height = r;
g.fillRect(x, y, width, height);
g.setColor(Color.WHITE);
if (type == 'S')
g.fillArc(x + r / 4, y + r / 4, width / 2, height / 2, 0, 360);
if (type == 'E'){
g.fillArc(x + r / 4, y + r / 4, width / 2, height / 2, 0, 360);
g.setColor(Color.black); }
g.fillRect('E'*TILE_SIZE,'E'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
g.setColor(g.getColor().darker());
g.drawRect('E'*TILE_SIZE,'E'*TILE_SIZE,TILE_SIZE,TILE_SIZE);
}


void showMaze(String maze, int milliseconds) {
int a = milliseconds;
a = 1500;
this.maze = maze;
repaint();
try {
Thread.sleep(a);
} catch (Exception e) {
}
}

public void update(Graphics g) {
paint(g);
}
}
public static void main(String [] a)
{ Screen screen = new Screen();
Maze maze = new Maze();

Button sm = new Button(" Solve Maze ");
Button exit = new Button(" Exit ");
TextField tb = new TextField(20 );
Label button = new Label(" Algorithm: ");
sm.setBackground(Color.green);
exit.setBackground(Color.red);
button.setBackground(Color.pink);
screen.add(button);
screen.add(tb );
screen.add(sm );
screen.add(exit );
screen.setLayout(new FlowLayout());
screen.setVisible(true);


int milliseconds = 4000;
maze.searchExit(screen, milliseconds);

}
}

Class Maze has got class Screen as sub class they works fine, i got another class C with load button. when i hit load button i want to run class Maze. hope you clicked me. thank you.

emint,

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Dear AdataPost
pls help me if error i have made on that program. thx

Write code of main() method of class Maze into actionPerformed() method of class C.

I Did but i got error in run time

Did you run maze from class c successfully? i could not do so!