关于java:Java实验使用GUI实现文本文件读写显示

import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JFrame;
public class GUIDemo extends JFrame{

private static final String TARGET_FILE = "./temp.txt";//三个组件private JButton saveButton;private JButton loadButton;private TextArea textArea;//容器private Container container;//指标文件private File targetFile;public GUIDemo() throws IOException {    //设置title    super("File Demo");            //设置流布局    setLayout(new FlowLayout());    //获取容器    container = getContentPane();            //创立指标文件对象    targetFile = new File(TARGET_FILE);    if(targetFile.createNewFile()) {        System.out.println([电子钱包](https://www.gendan5.com/wallet.html)"文件不存在，创立胜利");    }else {        System.out.println("文件存在");    }    //三个组件    textArea = new TextArea();    saveButton = new JButton("save");    loadButton = new JButton("load");    //保留文件按钮点击事件    saveButton.addActionListener(new ActionListener() {                    @Override        public void actionPerformed(ActionEvent e) {                        try {                //关上文件字符输入流                FileWriter writer = new FileWriter(targetFile);                        //获取文本显示区文本                String result = textArea.getText();                                //写入文件                writer.write(result);                                    //敞开输入流                writer.close();                //清空文本显示区内容                textArea.setText("");                                    System.out.println("存档胜利");            } catch (IOException e1) {                // TODO Auto-generated catch block                e1.printStackTrace();            }        }    });    //读入文件按钮点击事件    loadButton.addActionListener(new ActionListener() {        @Override        public void actionPerformed(ActionEvent e) {                            try {                //字符读入流                FileReader reader = new FileReader(targetFile);                                    //读入缓冲区                char[] buffer = new char[1024];                                    //读入后果                StringBuffer result = new StringBuffer();                                    //每次读入缓冲区的长度                int len;                                    //从读入流中读取文件内容并造成后果                while((len = reader.read(buffer)) != -1) {                    result.append(buffer,0,len);                }                                //敞开读入流                reader.close();                                    //更新文本显示区内容                textArea.setText(result.toString());                                System.out.println("读档胜利");            } catch (FileNotFoundException e1) {                // TODO Auto-generated catch block                e1.printStackTrace();            } catch (IOException e1) {                // TODO Auto-generated catch block                e1.printStackTrace();            }        }    });    //装填三个组件    container.add(textArea);    container.add(loadButton);    container.add(saveButton);    //调整大小    setSize(500, 300);    //显示    setVisible(true);}public static void main(String[] args) throws IOException {    GUIDemo demo = new GUIDemo();    demo.setDefaultCloseOperation(EXIT_ON_CLOSE);}

}