filedemo1.java

这是一个JAVA入门的小小的学习程序

//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; //
private JButton saveButton;
private JLabel label;
private FileOutputStream outFile;
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 saved to file test.txt!");
} 
catch(IOException e)
{ 
JOptionPane.showMessageDialog(this,"Error when writing to file or closing the File!","Error",JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
}
}
public static void main(String [] args)
{
FileDemo1 fileDemo1=new FileDemo1();
fileDemo1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}