Thread: java GUI , reading in files

hello! im working ona program that reads in a file called pot4.asc. my button Read File , is supposed to read in a file when clicked. i already have all the work done in my model class , im just trying to get it to work with a GUI and a button. i cant figure out what im doing wrong.

my action listener is at the bottom , i called my model class and its readFromFile. shouldnt that work? im thinking maybe i missed something with the textfield?

 
 
 
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
 
public class Gui {
	public static void main(String[] args) {
		JFrame frame = new JFrame("TeaPot");
 
		JTextField textField = new JTextField("pot4.asc",10);
 
 
 
		GridLayout applicationLayout = new GridLayout(1,2);
		frame.setLayout(applicationLayout);
 
		JPanel rightPanel = new JPanel();
		JPanel leftPanel = new JPanel();
 
		rightPanel.add(textField);
 
		GridLayout canvasLayout = new GridLayout(1,1);
		leftPanel.setLayout(canvasLayout);
 
		MyCanvas canvas = new MyCanvas(300,300);
		leftPanel.add(canvas);
 
		FlowLayout buttonLayout = new FlowLayout();
		rightPanel.setLayout(buttonLayout);
 
		JButton button1 = new JButton("Read In Data");
		button1.addActionListener(new eventRead());
		rightPanel.add( button1 );
 
		JButton button2 = new JButton("Write Out");
		button2.addActionListener(new eventWrite());
		rightPanel.add( button2 );
 
		JButton button3 = new JButton("Statistical Data");
		button3.addActionListener(new eventPrintStatistics());
		rightPanel.add( button3 );
 
 
		frame.add(leftPanel);
		frame.add(rightPanel);
 
 
		frame.setSize(800, 400);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(
				JFrame.EXIT_ON_CLOSE);
	}
}
 
 
class eventRead implements ActionListener{
 
	public void actionPerformed(ActionEvent e) {
		String inputFilename = "pot4.asc";
		JLabel label = new JLabel("Data Read");
		Model m = new Model();
		try{	    
			m.readFromFile(inputFilename);
			label.setText("File Read");
			System.out.println("File Read");
		} catch (Exception e1){
			System.out.println(e1.getMessage());
			inputFilename="pot4.asc";
			System.out.println("Using "+ inputFilename+ " instead");
 
		}
 
	}
 
 
 
}

model class

 
 
 
import java.io.*;
import java.util.ArrayList;
import java.util.Scanner;
 
public class Model {
 
	ArrayList<Triangle> triangleArray = new ArrayList<Triangle>();
 
	void readFromFile(String filename) throws Exception {
		File file = new File(filename);
		readFromFile(file);
	}
 
	void writeDataToFile(File file) {
		try{
 
			PrintWriter out = new PrintWriter(file);
			for(Triangle t: triangleArray){
				out.println("triangle");
				out.print( t.toString() );
 
			}
			out.close();
		}catch(Exception e){
 
		}
	}
 
 
 
	void writeInfoToFile(File file) {
		double area = computeSurfaceArea();
		double nTriangle = triangleArray.size();
		double min = computeMin();
		double max= computeMax();
		double averageArea = area / nTriangle;
 
		try{
 
			PrintWriter out = new PrintWriter(file);
			out.println("Total number of triangles = "+nTriangle);
			out.println("Area = "+area);
			out.println("Min = "+min);
			out.println("Max = "+max);
			out.println("Average Area = "+averageArea);
 
 
 
			out.close();
		}catch(Exception e){
			e.printStackTrace();
		}
	}
 
	void readFromFile(File file) throws Exception {
		try {
 
			Scanner s2 = new Scanner(file);
			while (s2.hasNext()) {
				s2.nextLine(); // tosss the first line
				String[] threeLines = { //array with 3 lines, reads in 3 lines
						s2.nextLine(), 
						s2.nextLine(),
						s2.nextLine() 
				};
 
				Triangle newTriangleObject = new Triangle(threeLines);
				triangleArray.add( newTriangleObject );
			}
		} catch (Exception e) {
			System.out.println("Model.readFromFile: "+e.getMessage());
			String bottle = "error: "+e.getMessage();
			throw new Exception(bottle);
			//e.printStackTrace();
		}
	}
 
	double computeSurfaceArea() {
		double v = 0;
		// loop through each triangle and sum up their areas
		for ( Triangle t : triangleArray )
		{
			double sArea = t.computeArea();
			v += sArea;
		}
		return v;
	}
 
 
	double computeMax(){
		double max= -Double.MAX_VALUE;
		for(Triangle t: triangleArray){
			max = (max > t.computeArea() ? max : t.computeArea());
 
		}
 
		return max;
 
	}  
 
	double computeMin(){  
		double min= Double.MAX_VALUE;
		for ( Triangle t : triangleArray) {
 
			if (min > t.computeArea() ){
				min =t.computeArea();
 
			} 
 
		}
		return min;
 
	}  
 
 
 
}

my problem is that my actionlistener isnt reading in the data right. everytime i hit the read button , it creates a model each time and the variable is only visible in that context making the model not accessible outside. how could i fix that? would making the model outside the actionPerformed method fix that?

 
class eventRead implements ActionListener{
 
	public void actionPerformed(ActionEvent e) {
		String inputFilename = "pot4.asc";
		JLabel label = new JLabel("Data Read");
		Model m = new Model();
		try{	    
			m.readFromFile(inputFilename);
			label.setText("File Read");
			System.out.println("File Read");
		} catch (Exception e1){
			System.out.println(e1.getMessage());
			inputFilename="pot4.asc";
			System.out.println("Using "+ inputFilename+ " instead");
 
		}
 
	}

i see what you mean , about the teh variable m. but i cant figure out how to fix it. would i just create another reference to the model object outside the listener?

im creating the model object inside the method because i was calling the method readFromFile thats in the model class, that already does the work for reading in files. i figured all i had to do was just create the listener and create the model object and call the readFromFile() method to do the work. for it to be class variable it would need to e static right? that would kind of ruin my model class lol.

argg sorry , but im really spazzing out here lol. i dont quite get what im supposed to do. ok , so ur saying i should declare it outside of the method and use it in the method. so im in my GUI class , which is were the Reading takes place. i should make my object outside of the listener , so i did this. i defined model right at the beginning of the code. then how could i access it inside the listener? i appologize if this is totally wrong lol

 
 
 
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
 
public class Gui {
 
	Model m = new Model();
	public static void main(String[] args) {
		JFrame frame = new JFrame("TeaPot");
 
		JTextField textField = new JTextField("pot4.asc",10);
 
 
 
		GridLayout applicationLayout = new GridLayout(1,2);
		frame.setLayout(applicationLayout);
 
		JPanel rightPanel = new JPanel();
		JPanel leftPanel = new JPanel();
 
		rightPanel.add(textField);
 
		GridLayout canvasLayout = new GridLayout(1,1);
		leftPanel.setLayout(canvasLayout);
 
		MyCanvas canvas = new MyCanvas(300,300);
		leftPanel.add(canvas);
 
		FlowLayout buttonLayout = new FlowLayout();
		rightPanel.setLayout(buttonLayout);
 
		JButton button1 = new JButton("Read In Data");
		button1.addActionListener(new eventRead());
		rightPanel.add( button1 );
 
		JButton button2 = new JButton("Write Out");
		button2.addActionListener(new eventWrite());
		rightPanel.add( button2 );
 
		JButton button3 = new JButton("Statistical Data");
		button3.addActionListener(new eventPrintStatistics());
		rightPanel.add( button3 );
 
 
		frame.add(leftPanel);
		frame.add(rightPanel);
 
 
		frame.setSize(800, 400);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(
				JFrame.EXIT_ON_CLOSE);
	}
}
 
 
class eventRead implements ActionListener{
 
 
	public void actionPerformed(ActionEvent e) {
		String inputFilename = "pot4.asc";
		JLabel label = new JLabel("Data Read");
		try{	    
			m.readFromFile(inputFilename);
			label.setText("File Read");
			System.out.println("File Read");
		} catch (Exception e1){
			System.out.println(e1.getMessage());
			inputFilename="pot4.asc";
			System.out.println("Using "+ inputFilename+ " instead");
 
		}
 
	}
 
 
 
 
}

it wont compile , because i cant access model in the actionlistener. i cant call m.readFromFile. it says m cannot be resolved.

class eventRead implements ActionListener{
 
 
	public void actionPerformed(ActionEvent e) {
		String inputFilename = "pot4.asc";
		JLabel label = new JLabel("Data Read");
		try{	    
			m.readFromFile(inputFilename);
			label.setText("File Read");
			System.out.println("File Read");
		} catch (Exception e1){
			System.out.println(e1.getMessage());
			inputFilename="pot4.asc";
			System.out.println("Using "+ inputFilename+ " instead");
 
		}
 
	}