Arraylist和JTextArea显示问题(Arraylist and JTextArea Display issue)

 我想知道是否有人可以指出我正确的方向。 
 
 我正在尝试创建一个接受输入的GUI，当按下按钮时，它会将其添加到JTextArea。 
 我希望能够继续这样做，直到单击退出按钮。 
 
 我可以得到第一个显示的输入，但是我花了很多时间试图弄清楚如何继续添加输入直到单击退出按钮。 
 
import javax.swing.*; 
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.util.ArrayList;

public class Window extends JFrame{

    private final int WIDTH=400;
    private final int HEIGHT=200;
    private JButton button;
    private JTextArea textArea;
    private JTextField textField;
    private JPanel panel;
    private JButton exit;

    public Window() {

        super("TextArea");
        setSize(WIDTH, HEIGHT);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        buildPanel();
        add(panel); 
        setVisible(true);   
    }

    public void buildPanel(){

        panel= new JPanel();
        textField = new JTextField(10); 
        textArea = new JTextArea();
        button = new JButton("Add");
        button.addActionListener(new Calc()); 
        exit = new JButton("exit");
        exit.addActionListener(new ExitListener());  
        panel.add(textField);       
        panel.add(button);
        panel.add(exit);
        panel.add(textArea);
    }  

    private class Calc implements ActionListener{
        public void actionPerformed(ActionEvent e){
            ArrayList<String> array= new ArrayList<String>();
            String str = (String) textField.getText();
            array.add(str);
            textArea.setText(str);
        }
    }

    private class ExitListener implements ActionListener{
        public void actionPerformed(ActionEvent e){
            System.exit(0);
        }
    }

    public static void main(String []args){
        new Window();
    }
}

I was wondering if someone can point me in the right direction.
 
I am trying to create a GUI that takes input, and when a button is pressed it adds it to a JTextArea.
 I want to be able to keep doing this until the exit button is clicked.
 
I can get the first input to display, but I have spent a lot of time trying to figure out how to keep adding input till the exit button is clicked. 
 
import javax.swing.*; 
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.util.ArrayList;

public class Window extends JFrame{

    private final int WIDTH=400;
    private final int HEIGHT=200;
    private JButton button;
    private JTextArea textArea;
    private JTextField textField;
    private JPanel panel;
    private JButton exit;

    public Window() {

        super("TextArea");
        setSize(WIDTH, HEIGHT);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        buildPanel();
        add(panel); 
        setVisible(true);   
    }

    public void buildPanel(){

        panel= new JPanel();
        textField = new JTextField(10); 
        textArea = new JTextArea();
        button = new JButton("Add");
        button.addActionListener(new Calc()); 
        exit = new JButton("exit");
        exit.addActionListener(new ExitListener());  
        panel.add(textField);       
        panel.add(button);
        panel.add(exit);
        panel.add(textArea);
    }  

    private class Calc implements ActionListener{
        public void actionPerformed(ActionEvent e){
            ArrayList<String> array= new ArrayList<String>();
            String str = (String) textField.getText();
            array.add(str);
            textArea.setText(str);
        }
    }

    private class ExitListener implements ActionListener{
        public void actionPerformed(ActionEvent e){
            System.exit(0);
        }
    }

    public static void main(String []args){
        new Window();
    }
}

原文：