setDefaultCloseOeration的问题

Question

import java.io.*;public class TextFileWriter {
PrintWriter out;

public TextFileWriter(String fileName,boolean append)throws IOException{
            out = new PrintWriter(
             new BufferedWriter(
             new FileWriter(fileName,append)));
} public final void output(String...text){
              
               for (String s: text)
                   out.print(s + "|");
out.println();
}

public final void closeFile(){
out.close();
}
}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;public class ProductTextFileWriterFrame extends Frame{
ProductTextFileWriterFrame(){
setTitle("产品文本文件输入程序");
centerWindow(this);
setSize(300,220);
setResizable(false);
setDefaultCloseOeration(JFrame.EXIT_ON_CLOSE);
JPanel panel = new ProductTextFileWriterPanel();
this.add(panel);
}

private void centerWindow(Window w){
Toolkit tk=Toolkit.getDefaultToolkit();
Dimension d=tk.getScreenSize();
setLocation((d.width-w.getWidth()) / 2,(d.height-w.getHeight() / 2)); 
}

class ProductTextFileWriterPanel extends JPanel implements ActionListener{

private JTextField  IDTextField,
                    titleTextField,
                    priceTextField,
                    infoTextField;
private JLabel      IDLabel,
                    titleLabel,
                    priceLabel,
                    infoLabel,
                    countLabel;
private JButton     saveButton,
                    exitButton;

private TextFileWriter fileWriter;
private String fileName = "/home/cactus/桌面/临时文件/test/product.txt";
private int count;

public ProductTextFileWriterPanel(){

JPanel productFilePanel = new JPanel();
productFilePanel.setLayout(new FlowLayout(FlowLayout.RIGHT));

IDLabel = new JLabel("产品编号");
productFilePanel.add(IDLabel);

IDTextField = new JTextField(20);
productFilePanel.add(IDTextField);

titleLabel = new JLabel("产品名");
productFilePanel.add(titleLabel);

titleTextField = new JTextField(20);
productFilePanel.add(titleTextField);

priceLabel = new JLabel("产品名");
productFilePanel.add(priceLabel);

priceTextField = new JTextField(20);
productFilePanel.add(priceTextField);

infoLabel = new JLabel("数据存储至");
productFilePanel.add(infoLabel);
infoLabel.setVisible(false);

infoTextField = new JTextField(20);
infoTextField.setEditable(false);
infoTextField.setFocusable(false);
productFilePanel.add(infoTextField);
infoTextField.setVisible(false);

countLabel = new JLabel();
productFilePanel.add(countLabel);

//button panel
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));

saveButton = new JButton("保存");
    saveButton.addActionListener(this);
buttonPanel.add(saveButton);

exitButton = new JButton("退出");
exitButton.addActionListener(this);
buttonPanel.add(exitButton);

    this.setLayout(new BorderLayout());
    this.add(productFilePanel,BorderLayout.CENTER);
    this.add(buttonPanel,BorderLayout.NORTH);
    try{
     fileWriter = new TextFileWriter(fileName,true);
    
    }
    catch (IOException e){
     System.out.println(e);
    }     count = 0;
}

public void actionPerformed(ActionEvent e){

if (e.getSource() == exitButton){
fileWriter.closeFile();
System.exit(0);
}
else if (e.getSource() == saveButton){
String ID = IDTextField.getText();
String title= titleTextField.getText();
String price = priceTextField.getText();
fileWriter.output(ID,title,price);

IDTextField.setText("");
titleTextField.setText("");
priceTextField.setText("");

infoLabel.setVisible(true);
infoTextField.setVisible(true);
infoTextField.setText(fileName);
countLabel.setText("已存记录:                    " + ++count );
}
}
} }setDefaultCloseOpration();方法提示错误，怎么改。

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;public class ProductTextFileWriterFrame extends JFrame{
    ProductTextFileWriterFrame(){
        setTitle("产品文本文件输入程序");
        centerWindow(this);
        setSize(300,220);
        setResizable(false);
        //setDefaultCloseOeration(JFrame.EXIT_ON_CLOSE);
        //首先要继承JFrame，而不是Frame；其次是方法名要写正确，你自己看看！
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new ProductTextFileWriterPanel();
        this.add(panel);
    }
    
    private void centerWindow(Window w){
        Toolkit tk=Toolkit.getDefaultToolkit();
        Dimension d=tk.getScreenSize();
        setLocation((d.width-w.getWidth()) / 2,(d.height-w.getHeight() / 2)); 
    }
    
    class ProductTextFileWriterPanel extends JPanel implements ActionListener{
        
        private JTextField  IDTextField,
                            titleTextField,
                            priceTextField,
                            infoTextField;
        private JLabel      IDLabel,
                            titleLabel,
                            priceLabel,
                            infoLabel,
                            countLabel;
        private JButton     saveButton,
                            exitButton;
        
        private TextFileWriter fileWriter;
        private String fileName = "/home/cactus/桌面/临时文件/test/product.txt";
        private int count;
        
        public ProductTextFileWriterPanel(){
            
            JPanel productFilePanel = new JPanel();
            productFilePanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
            
            IDLabel = new JLabel("产品编号");
            productFilePanel.add(IDLabel);
            
            IDTextField = new JTextField(20);
            productFilePanel.add(IDTextField);
        
            titleLabel = new JLabel("产品名");
            productFilePanel.add(titleLabel);
            
            titleTextField = new JTextField(20);
            productFilePanel.add(titleTextField);
            
            priceLabel = new JLabel("产品名");
            productFilePanel.add(priceLabel);
            
            priceTextField = new JTextField(20);
            productFilePanel.add(priceTextField);
            
            infoLabel = new JLabel("数据存储至");
            productFilePanel.add(infoLabel);
            infoLabel.setVisible(false);
            
            infoTextField = new JTextField(20);
            infoTextField.setEditable(false);
            infoTextField.setFocusable(false);
            productFilePanel.add(infoTextField);
            infoTextField.setVisible(false);
            
            countLabel = new JLabel();
            productFilePanel.add(countLabel);
    
            //button panel
            JPanel buttonPanel = new JPanel();
            buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
            
            saveButton = new JButton("保存");
            saveButton.addActionListener(this);
            buttonPanel.add(saveButton);
            
            exitButton = new JButton("退出");
            exitButton.addActionListener(this);
            buttonPanel.add(exitButton);
            
            this.setLayout(new BorderLayout());
            this.add(productFilePanel,BorderLayout.CENTER);
            this.add(buttonPanel,BorderLayout.NORTH);
            try{
                fileWriter = new TextFileWriter(fileName,true);
                
            }
            catch (IOException e){
                System.out.println(e);
            }            count = 0;
        }
        
        public void actionPerformed(ActionEvent e){
            
            if (e.getSource() == exitButton){
                fileWriter.closeFile();
                System.exit(0);
            }
            else if (e.getSource() == saveButton){
                String ID = IDTextField.getText();
                String title= titleTextField.getText();
                String price = priceTextField.getText();
                fileWriter.output(ID,title,price);
                
                IDTextField.setText("");
                titleTextField.setText("");
                priceTextField.setText("");
                
                infoLabel.setVisible(true);
                infoTextField.setVisible(true);
                infoTextField.setText(fileName);
                countLabel.setText("已存记录:                    " + ++count );
            }
        }
    } }程序中注释了！