filedemo1.java

JAVA学习源代码,大家可以好好参考,请多提宝贵意见

//FileDemo1.java
import java.io.*;
import java.awt.*;
import java.awt.event.*; 
import javax.swing.*;

public class FileDemo1
    extends JFrame
    implements ActionListener {
  private JTextArea inputTextArea;   //文件输入区域
  private JButton saveButton;           //保存按钮
  private JLabel label;                        //提示用户输入
  private FileOutputStream outFile;   //输出文件流
  public FileDemo1(){
    Container container = getContentPane();
    container.setLayout(new FlowLayout());
    label = new JLabel("Please input file content :");
    label.setForeground(Color.red);
    container.add(label, BorderLayout.NORTH);
    inputTextArea = new JTextArea("", 10, 20);
    inputTextArea.setEditable(true);
    container.add(new JScrollPane(inputTextArea), BorderLayout.CENTER);
    saveButton = new JButton("Save");
    container.add(saveButton, BorderLayout.SOUTH);
    saveButton.addActionListener(this);
    setSize(300, 300);
    setVisible(true);
  }
  //事件处理
  public void actionPerformed(ActionEvent event) {
    if (event.getSource() == saveButton) {
      try {
        outFile = new FileOutputStream(new File("test.txt"));
        //将用户写入信息保存到文件
        outFile.write(inputTextArea.getText().getBytes(), 0,
                      inputTextArea.getText().length());
        outFile.close();
        //提示操作成功
        JOptionPane.showMessageDialog(this,"The content has been saved to file test.txt !");
      }
      catch (IOException e) {
        //发生异常时，给出提示信息
        JOptionPane.showMessageDialog(this,"Error when writing to file or closing the file !"
                                           , "Error", JOptionPane.ERROR_MESSAGE);
        System.exit(1);   //退出
      }
    }
  }

  public static void main(String[] args){
    FileDemo1 fileDemo1 = new FileDemo1();
    fileDemo1.setDefaultCloseOperation(
        JFrame.EXIT_ON_CLOSE);
  }
}