import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.ImageIcon;
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;
public class NotePad extends JFrame implements ActionListener{
JScrollPane jsp=null;
JTextArea jta=null;
JMenuBar jmb=null;
JMenu jm=null;
JMenuItem jmi1=null;
JMenuItem jmi2=null;
//构造方法
public NotePad() {
jta=new JTextArea();
jsp=new JScrollPane(jta);
jmb=new JMenuBar();
jm=new JMenu("文件");
jmi1=new JMenuItem("打开");
jmi1.addActionListener(this);
jmi2=new JMenuItem("另存为");
jmi2.addActionListener(this);
jm.add(jmi1);
jm.add(jmi2);
jmb.add(jm);
this.add(jmb,"North");
this.add(jsp);
}
//main
public static void main(String[] args){
NotePad np=new NotePad();
np.setSize(400,600);
ImageIcon ico=new ImageIcon(np.getClass().getResource("/createNew.jpg"));
np.setIconImage(ico.getImage());
np.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
np.setTitle("记事本");
np.setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e) {
if(e.getActionCommand().equals("打开")){
JFileChooser jfc=new JFileChooser();
jfc.showOpenDialog(null);
String file=jfc.getSelectedFile().getAbsolutePath();
FileReader fr=null;
BufferedReader br=null;
try{
fr=new FileReader(file);
br=new BufferedReader(fr);
/**这两个字符串变量必须要**/
String conStr="";
String tmpStr="";
while((tmpStr=br.readLine())!=null){
//conStr+=br.readLine()+"\r\n";//不能这么写，不然没运行一次br.readLine()指针就会移动
conStr+=tmpStr+"\r\n";
}
jta.setText(conStr);
}catch(Exception e1){
e1.printStackTrace();
}finally{
try {
br.close();
fr.close();
} catch (Exception e2) {
// TODO: handle exception
}
}
jfc.setVisible(true);
}else if(e.getActionCommand().equals("另存为")){
JFileChooser jfc=new JFileChooser();
jfc.showSaveDialog(null);
jfc.setVisible(true);
String content=jta.getText();
String file=jfc.getSelectedFile().getAbsolutePath();
FileWriter fw=null;
BufferedWriter bw=null;
try {
fw=new FileWriter(file);
bw=new BufferedWriter(fw);
bw.write(content);
bw.flush();
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}finally{
try {
bw.close();
fw.close();
} catch (Exception e2) {
// TODO: handle exception
}
}
}
}
}