Question

我使用FileWriter制作了一个Note程序。它工作得很好，除非我写了一个长音符，音符只会保存在一行中。我有什么方法可以让它在一定数量的字符后写入下一行吗？这是我的代码：

import static javax.swing.JOptionPane.*;
import static java.lang.Integer.*;
import static java.lang.System.*;
import static java.lang.Double.*;
import static java.lang.Math.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.text.*;
import java.awt.*;
import java.io.*;


public class Note extends JFrame implements ActionListener {
JTextArea area;
JTextField title;
JLabel titleTxt, noteTxt;
JButton save, clear, exit;
FileWriter writer=null;
PrintWriter gen =null;
Scanner reader =null;
boolean append = true;

public static void main(String[] args) {
    Note window = new Note();
    window.setTitle("Note");
    window.setLocationRelativeTo(null);
    window.setDefaultCloseOperation(EXIT_ON_CLOSE);
    window.createGUI();
    window.setSize(300,250);
    window.setResizable(false);
    window.setVisible(true);
}

public void createGUI() {
setLayout ( new FlowLayout() );

    titleTxt = new JLabel("Title:");
    add(titleTxt);

    title = new JTextField(30);
    add(title);

    noteTxt = new JLabel("Note:");
    add(noteTxt);

    area = new JTextArea(5,25);
    area.setLineWrap(true);
    area.setWrapStyleWord(true);
    JScrollPane field = new JScrollPane(area);
    add(field);

    save = new JButton("Save");
    save.addActionListener(this);
    add(save);

    clear = new JButton("Clear");
    clear.addActionListener(this);
    add(clear);

    exit = new JButton("Exit");
    exit.addActionListener(this);
    add(exit);

}

public void actionPerformed(ActionEvent e){
    if(e.getSource() == save){
        Save();
        area.setText("");
        title.setText("");
    }
    else if(e.getSource() == clear){
        area.setText("");
        title.setText("");
    }
    else if(e.getSource() == exit){
        System.exit(0);
    }

}

private void Save(){

    String date = new SimpleDateFormat("dd-MM-yyyy").format(Calendar.getInstance().getTime());
    String timeStamp = new SimpleDateFormat("HH:mm:ss").format(Calendar.getInstance().getTime());

    String outTxt = "Note is saved";

    try{

        //FileWriting
        File file = new File(date+".txt");
        writer = new FileWriter(file,append);
        writer.write("Tid: "+timeStamp+"\r\n");
        writer.write("\r\n");
        writer.write(title.getText()+"\r\n");
        writer.write("\r\n");

        writer.write(area.getText()+"\r\n");
        writer.write("\r\n");
        writer.write("\r\n");
        writer.close();

    }


        catch (FileNotFoundException e){
                outTxt="File Not Found";
            }

            catch (Exception e){
                outTxt="Error";
            }
            finally {
                if (reader!=null)reader.close();
                showMessageDialog(null, outTxt);
            }

        }


}

Answer 1

最简单的方法是做这样的事情：

 try{

        //FileWriting
        File file = new File(date+".txt");
        writer = new FileWriter(file,append);
        writer.write("Tid: "+timeStamp+"\r\n");
        writer.write("\r\n");
        writer.write(title.getText().replaceAll("(.{50}[^ ]+)\\s+", "$1\r\n")+"\r\n");
        writer.write("\r\n");

        writer.write(area.getText().replaceAll("(.{50}[^ ]+)\\s+", "$1\r\n")+"\r\n");
        writer.write("\r\n");
        writer.write("\r\n");
        writer.close();

    }

这将替换50个字符和任何后续非空格字符，并将它们放在一个组中，并将它们替换为同一组和\r\n。

需要FileWriter在long String中输入一定数量的字符后写入下一行

1 个答案: