为什么运行这个程序后点击保存，然后打开时不是按行输出的啊?哪里有问题？publicclassJSBJSB{publicstaticvoidmain(String[]args){FirstWindowwin=newFirstWindow("记事本");}}classF...

为什么运行这个程序后点击保存，然后打开时不是按行输出的啊?哪里有问题？

public class JSBJSB{

public static void main(String[] args) {

FirstWindow win=new FirstWindow("记事本");

}

}

class FirstWindow extends JFrame implements ActionListener{

private static final long serialVersionUID = 1L;

JMenuBar menubar;

JMenu menu2,menu1;

JMenuItem item1,item2,itema,itemb,itemc,itemd;

JTextArea showText;

JFileChooser fileChooser1,fileChooser2;

FirstWindow(String s){

fileChooser1=new JFileChooser("c;/");

fileChooser2=new JFileChooser("c;/");

setTitle(s);

setSize(750, 450);

setLocation(250,120);

setVisible(true);

menubar=new JMenuBar();

menu1=new JMenu("文件");

item1=new JMenuItem("打开");

item2=new JMenuItem("保存");

menu1.add(item1);

menu1.addSeparator();

menu1.add(item2);

menubar.add(menu1);

validate();

menu2=new JMenu("编辑");

itema=new JMenuItem("复制");

itemb=new JMenuItem("剪切");

itemc=new JMenuItem("粘贴");

itemd=new JMenuItem("全部选中");

menu2.add(itema);

menu2.addSeparator();

menu2.add(itemb);

menu2.addSeparator();

menu2.add(itemc);

menu2.addSeparator();

menu2.add(itemd);

menubar.add(menu2);

setJMenuBar(menubar);

validate();

showText=new JTextArea(12,12);

add(new JScrollPane(showText));

setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

validate();

itema.addActionListener(this);

itemb.addActionListener(this);

itemc.addActionListener(this);

itemd.addActionListener(this);

item1.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

int n=fileChooser1.showOpenDialog(null);

if(n==JFileChooser.APPROVE_OPTION){

File file=fileChooser1.getSelectedFile();

try{

FileReader readfile=new FileReader(file);

BufferedReader in=new BufferedReader(readfile);

String s=null;

while((s=in.readLine())!=null)showText.append(s+"\n");

}

catch(IOException ee){}

}

}

});

item2.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

int n=fileChooser2.showSaveDialog(showText);

if(n==JFileChooser.APPROVE_OPTION){

File file=fileChooser2.getSelectedFile();

try{

FileWriter tofile=new FileWriter(file+".txt");

BufferedWriter out=new BufferedWriter(tofile);

out.write(showText.getText());

out.close();

}

catch(IOException ee){}

}

}

});

}

public void actionPerformed(ActionEvent e) {

if(e.getSource()==itema)

showText.copy();

if(e.getSource()==itemb)

showText.cut();

if(e.getSource()==itemc)

showText.paste();

if(e.getSource()==itemd)

showText.selectAll();

}}

import java.awt.MenuItem;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import javax.swing.JFileChooser;

import javax.swing.JFrame;

import javax.swing.JMenu;

import javax.swing.JMenuBar;

import javax.swing.JMenuItem;

import javax.swing.JScrollPane;

import javax.swing.JTextArea;

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