Passing an array to another class in a JFrame

[George5432]

import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;

public class Array extends JFrame {

   private JTextField number = new JTextField(10);
   private JLabel result;
   int num;
   ArrayList<Integer> list = new ArrayList<>();
   ArrayList coll;

   public static void main(String[] args) {

      // create a frame
      Array frame = new Array();
      frame.setTitle("Collections");
      frame.setSize(700, 300);
      frame.setLocationRelativeTo(null);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setVisible(true);

   }

   public Array() {

      // add labels and text fields to the frame
      add(new JLabel("You can add 50 numbers."), BorderLayout.NORTH);
      setLayout(new FlowLayout(FlowLayout.LEFT, 10, 20));
      add(new JLabel("Enter a number and click the enter button:"));
      add(number);

      // add Enter button
      JButton jbtEnter = new JButton("Enter");
      jbtEnter.setToolTipText("This will store your number in the program");
      add(jbtEnter);

      // create actionListener for the Enter button
      jbtEnter.addActionListener(new EnterListener());

      // create Display Button
      JButton jbtDisplay = new JButton("Display");
      jbtDisplay
            .setToolTipText("This will display all the integers in numberical order");
      add(jbtDisplay);

      // create actionListener for Display button
      jbtDisplay.addActionListener(new DisplayListener());

      result = (new JLabel(""));
      add(result);
   }

   // this is what happens when the Enter button is clicked
   class EnterListener implements ActionListener {
      @Override
      public void actionPerformed(ActionEvent e) {

         // loop so user cannot enter more than 50 numbers
         for (int i = 0; i < 50; i++) {
            if (i < 50) {
               num = Integer.parseInt(number.getText());
               list.add(num);
               i++;
            } else
               throw new IllegalArgumentException(
                     "You have entered all 50 numbers.");
         }
         number.setText(null);
      }
   }

   // this is what happens when the Display button is selected
   class DisplayListener implements ActionListener {

      @Override
      public void actionPerformed(ActionEvent e) {

         // trying to make the variable coll equal to the array list in the
         // class above
         coll = Collections.sort(coll);
         result.setText("The numbers you have entered, listed in numerical order is:"
               + coll);
      }

   }

}

In the DisplayListener, how do I bring the array from EnterListener to the variable coll in DisplayListener.

[Fubarable]

Your code is *very* hard to read. Please edit the post above and add [code] [/code] tags above and below your code blocks so that they retain their formatting. Also, feel free to flesh out your question, some, to add any detail that might help us understand your problem better. Also let us know what compiler errors you might be seeing (because surely you are seeing some based on the code abve), and the lines that are causing the errors.

[Fubarable]

And are you absolutely sure that you want to use that for loop in your EnterListener? 100% completely sure??

[George5432]

I would like to so the user can click enter to submit the entry. What would be your suggestion with EnterListener and without EnterListener?

[George5432]

The program looks like it would work if I can get the array to the variable coll in the DisplayListener.

[George5432]

Sorry, I misunderstood your question. If the loop can be changed and have the same out come, it does not matter if the for loop is there or not.

[Fubarable]

Again, please don't ignore my request that you edit your post so that we can read your code. If we can't read your code, we can't understand you code. If we can't understand your code, we can't help you. It's up to you.

Regarding your EnterListener, your for loop goes against the rules of getting data in an event-driven way. You can't use that for loop, but rather need to wait for the user to click the button each time he wants to enter another number. In other words, the listener code should be written to accept one new entry and that's it. He must click it 30 times to enter 30 numbers.

Regarding your other question, I'll await your edit to your original post.

[George5432]

Just figured out what you were talking about. I am new to this forum.

[Fubarable]

I have re-edited your original post. You only need one set of code tags per program or large block of code.

Your code as posted won't compile, and you'll need to fix the compilation errors first. Any questions about these?

[George5432]

Thanks for helping with the edit. I was having a hard time with that. I am trying to figure out line 82. That piece of code is incorrect. It should be coll = But I do not know what goes after the equals. I want coll to equal the array from the class above (EnterListener). Then coll would be the same array. Then I can enter the code Collections.sort(coll).

[Fubarable]

Thanks for helping with the edit. I was having a hard time with that. I am trying to figure out line 82. That piece of code is incorrect. It should be coll = But I do not know what goes after the equals. I want coll to equal the array from the class above (EnterListener). Then coll would be the same array. Then I can enter the code Collections.sort(coll).

Collections.sort(...) is not working as you expect it does. For one it modifies the collection passed into it, and for another it doesn't return anything (per the API, it returns void). So you simply pass the collection to be sorted into this method and call it and don't set it on the right side of any assignment statement.

But your other problem is that coll is empty. Why not use the other ArrayList, the one you've already filled up?

[George5432]

That is what I am trying to do. How do I bring that ArrayList down to the class DisplayListener. Bringing down what a user entered can be done by, an example name.getText(). I do not know how to do this with an ArrayList.

[Fubarable]

That is what I am trying to do. How do I bring that ArrayList down to the class DisplayListener

What happens when you try to use it there?

[George5432]

What happens when you try to use it there?

This is what I am trying to figure out how to use. coll = list.getText(); does not work

[George5432]

how would I get the already filled array to the coll?

[Fubarable]

This is what I am trying to figure out how to use. coll = list.getText(); does not work

No, what I'm suggesting is what happens if you don't even use a "coll" variable, but instead use list directly?

Also, don't call methods that don't exist. Instead you'll want to be very familiar with the Java API and use it frequently to check to see what methods are available for the class you are using. ArrayLists for instance have no getText() method that I know of, and you can't make one up and try to use it.

[George5432]

import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;


public class Array extends JFrame{
    
    private JTextField number = new JTextField(10);
    private JLabel result;
    int num;
    ArrayList<Integer> list = new ArrayList<>();
    
    
    public static void main(String[] args){
        
        Array frame = new Array();
        frame.setTitle("Collections");
        frame.setSize(700, 300);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        
        
    }
    
    public Array() {
    
       
        add(new JLabel("Enter 50 numbers."), BorderLayout.NORTH);
        setLayout(new FlowLayout(FlowLayout.LEFT, 10,20));
        add(new JLabel("Enter a number and click the enter button:"));
        add(number);
        
        JButton jbtEnter = new JButton("Enter");
        jbtEnter.setToolTipText("This will store your number in the program");
        add(jbtEnter);
        
        jbtEnter.addActionListener(new EnterListener());
        
        
        JButton jbtDisplay = new JButton("Display");
        jbtDisplay.setToolTipText("This will display all the integers in numberical order");
        add(jbtDisplay);
        
        jbtDisplay.addActionListener(new DisplayListener());
        
        result = (new JLabel(""));
        add (result);
}
    class EnterListener implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent e){
            
            for (int i = 0; i < 50; i++){
            if (i < 50){
                i++;
            num = Integer.parseInt(number.getText());
            list.add(num);
             
            } else
                throw new IllegalArgumentException("You have entered all 50 numbers.");
        }
            number.setText(null);
        }
    }
    
    class DisplayListener implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent e) {
            
            Collections.sort(list);
            result.setText("The numbers you have entered, listed in numerical order is:" + list );
        }

        
        }
        
    }

I did use your advice and just used the list. I did not see that before. thank you for that. This code runs but but the program will allow the numbers to exceed 50 entries.

[Fubarable]

Yes, and you're also still using that for loop and thus adding each number entered 50 (!!) times.

[George5432]

Can I have some advice on how to correct that? I am working on it as well. Just letting you know I am not just asking you to do this for me.

[George5432]

import javax.swing.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
 
 
public class Array extends JFrame{
     
    private JTextField number = new JTextField(10);
    private JLabel result;
    int num;
    ArrayList<Integer> list = new ArrayList<>();
     
     
    public static void main(String[] args){
         
        Array frame = new Array();
        frame.setTitle("Collections");
        frame.setSize(700, 300);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
         
         
    }
     
    public Array() {
     
        
        add(new JLabel("Enter 50 numbers."), BorderLayout.NORTH);
        setLayout(new FlowLayout(FlowLayout.LEFT, 10,20));
        add(new JLabel("Enter a number and click the enter button:"));
        add(number);
         
        JButton jbtEnter = new JButton("Enter");
        jbtEnter.setToolTipText("This will store your number in the program");
        add(jbtEnter);
         
        jbtEnter.addActionListener(new EnterListener());
         
         
        JButton jbtDisplay = new JButton("Display");
        jbtDisplay.setToolTipText("This will display all the integers in numberical order");
        add(jbtDisplay);
         
        jbtDisplay.addActionListener(new DisplayListener());
         
        result = (new JLabel(""));
        add (result);
}
    class EnterListener implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent e){
             
            int i = 0;
            if (i < 50){
                i++;
            num = Integer.parseInt(number.getText());
            list.add(num);
              number.setText(null);
            } else
                throw new IllegalArgumentException("You have entered all 50 numbers.");

        }
    }
     
    class DisplayListener implements ActionListener{
 
        @Override
        public void actionPerformed(ActionEvent e) {
             
            Collections.sort(list);
            result.setText("The numbers you have entered, listed in numerical order is:" + list );
        }
 
         
        }
         
    }