简易记事本
一:实验代码
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import static javax.swing.KeyStroke.*;
public class pluto implements ActionListener{
JFrame frame;
JMenuBar bar;
JMenu fileMenu, editMenu,formatMenu,viewMenu,helpMenu;
JMenuItem newItem, openItem, saveItem, closeItem;
ImageIcon newIcon, openIcon, saveIcon, closeIcon;
JScrollPane scroll;
JTextArea area;
JFileChooser chooser;
File file;
public pluto() {
frame = new JFrame("ZY");
bar = new JMenuBar();
fileMenu = new JMenu("文件(F)");
editMenu = new JMenu("编辑(E)");
formatMenu= new JMenu("格式(O)");
viewMenu=new JMenu("查看(V)");
helpMenu= new JMenu("帮助(H)");
newIcon = new ImageIcon("d:" + File.separator + "Test" + File.separator + "A.png");
openIcon = new ImageIcon("d:" + File.separator + "Test" + File.separator + "B.png");
saveIcon = new ImageIcon("d:" + File.separator + "Test" + File.separator + "C.png");
closeIcon = new ImageIcon("d:" + File.separator + "Test" + File.separator + "D.png");
newItem = new JMenuItem("新建(N)", newIcon);
openItem = new JMenuItem("打开(O)", openIcon);
saveItem = new JMenuItem("另存为(A)", saveIcon);
closeItem = new JMenuItem("关闭(X)", closeIcon);
area = new JTextArea();
scroll = new JScrollPane(area);
newItem.setMnemonic(KeyEvent.VK_N);
openItem.setMnemonic(KeyEvent.VK_O);
saveItem.setMnemonic(KeyEvent.VK_A);
closeItem.setMnemonic(KeyEvent.VK_X);
newItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, InputEvent.CTRL_MASK));
openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_MASK));
saveItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK));
closeItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK));
fileMenu.add(newItem);
fileMenu.add(openItem);
fileMenu.add(saveItem);
fileMenu.addSeparator();
fileMenu.add(closeItem);
newItem.addActionListener((ActionListener) this);
openItem.addActionListener((ActionListener) this);
saveItem.addActionListener((ActionListener) this);
closeItem.addActionListener((ActionListener) this);
bar.add(fileMenu);
bar.add(editMenu);
bar.add(formatMenu);
bar.add(viewMenu);
bar.add(helpMenu);
frame.setJMenuBar(bar);
frame.add(scroll);
frame.setVisible(true);
frame.pack();
}
public void actionPerformed(ActionEvent event) {
Object obj = event.getSource();
if (obj instanceof JMenuItem) {
JMenuItem item = (JMenuItem) obj;
//加入动作监听
if (item == newItem) {
new pluto();
}
else if(item==openItem){
JFileChooser chooser=new JFileChooser();
chooser.showOpenDialog(null);
file=chooser.getSelectedFile();//返回选择的文件
try {
FileInputStream fis=new FileInputStream(file);
try {
byte[] b=new byte[fis.available()];
fis.read(b);
area.append(new String(b));
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
else if (item==saveItem){
JFileChooser chooser = new JFileChooser();
chooser.showSaveDialog(null);
file=chooser.getSelectedFile();
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
try {
FileOutputStream fos=new FileOutputStream(file);
byte[] b = area.getText().getBytes();
try {
fos.write(b);
} catch (IOException ex) {
ex.printStackTrace();
}
try {
fos.close();
} catch (IOException ex) {
ex.printStackTrace();
}
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
}
}
}
else if(item==closeItem){
System.exit(1);
}
}
}
}
测试:
public class crush {
public static void main(String[] args) {
// TODO Auto-generated method stub
new pluto();
// TODO Auto-generated method stub
new pluto();
}
}
截图:



学习总结:去找了别人的记事本瞅瞅,还是有很多不懂的地方,还是要多练多学。听不大懂数据库。。。
后面那节课老师讲了很多选择题,正处于备考阶段,继续学习吧。。。。