java编写记事本详解编程语言

import java.awt.FileDialog; 
import java.awt.FlowLayout; 
import java.awt.event.*; 
import java.io.*; 
import java.util.*; 
import javax.swing.*; 
 
 
public class Not implements ActionListener, MouseListener { 
private ArrayList<String> al = new ArrayList<String>(); 
private int set = 0; 
private JFrame jf = new JFrame("Notepad"); 
private JTextArea jta = new JTextArea(20,40); 
JScrollPane jsp = new JScrollPane(jta); 
private JTextField jtf = new JTextField(10); 
private JTextField jtft = new JTextField(10); 
private JPopupMenu pp = new JPopupMenu(); 
private String target = null; 
private JDialog jd = new JDialog(jf, "警告"); 
 
public void actionPerformed(ActionEvent e) { 
String comm = e.getActionCommand(); 
if (comm.equals("新建...")) { 
 
if(!jta.getText().equals("")){ 
jd.setLocation(300, 300); 
jd.setVisible(true); 
}else{ 
jta.setText("1234548882"); 
} 
} 
if(comm.equals("否")){ 
jta.setText(""); 
jd.dispose();  
}  
if(comm.equals("取消")){ 
jd.dispose();  
} 
if (comm.equals("保存") || comm.equals("另存...")||comm.equals("是")) { 
if(comm.equals("是")) jd.dispose(); 
FileDialog fd = new FileDialog(jf, "打开...", FileDialog.SAVE); 
fd.setFilenameFilter(new FilenameFilter() { 
public boolean accept(File dir, String name) { 
return name.endsWith(".txt") || name.endsWith(".java"); 
} 
}); 
if (target == null || "另存...".equals(comm)) { 
fd.setVisible(true); 
} 
if (fd.getFile() != null) { 
target = fd.getFile(); 
try { 
FileOutputStream fos = new FileOutputStream(fd 
.getDirectory() 
+ target); 
byte[] b = jta.getText().getBytes(); 
for (byte by : b) { 
fos.write(by); 
} 
fos.close(); 
} catch (IOException e1) { 
e1.printStackTrace(); 
} 
} 
} 
if (comm.equals("打开...")) { 
al.add(jta.getText()); 
FileDialog fd = new FileDialog(jf, "打开...", FileDialog.LOAD); 
fd.setFilenameFilter(new FilenameFilter() { 
public boolean accept(File dir, String name) { 
return name.endsWith(".txt") || name.endsWith(".java"); 
} 
}); 
fd.setVisible(true); 
// 以下是打开文件 
target = fd.getFile(); 
String str = fd.getDirectory() + target; 
if (fd.getFile() != null) { 
try { 
String res = ""; 
FileInputStream fis = new FileInputStream(str); 
byte[] b = new byte[1024]; 
int count; 
while ((count = fis.read(b)) != -1) { 
res = res + new String(b, 0, count); 
} 
fis.close(); 
jta.setText(res); 
} catch (IOException e1) { 
e1.printStackTrace(); 
} 
} 
} 
if (comm.equals("退出")) { 
System.exit(0); 
} 
if (comm.equals("撤销")) { 
if(!al.isEmpty()){ 
jta.setText(al.get(al.size()-1)); 
al.remove(al.size()-1); 
} 
} 
if (comm.equals("剪切")) { 
al.add(jta.getText()); 
jta.cut(); 
} 
if (comm.equals("复制")) { 
al.add(jta.getText()); 
jta.copy(); 
} 
if (comm.equals("粘贴")) { 
al.add(jta.getText()); 
jta.paste(); 
} 
if (comm.equals("删除")) { 
al.add(jta.getText()); 
jta.cut(); 
} 
if ("查找...".equals(comm) || "替换...".equals(comm)) { 
JDialog jdct = new JDialog(jf,comm); 
 
String label = comm.substring(0, 2); 
JButton jb = new JButton(label); 
jb.addActionListener(this); 
jdct.setLayout(new FlowLayout()); 
jdct.add(jtf); 
if ("替换...".equals(comm)) { 
 
 
JLabel jlt = new JLabel(">"); 
jdct.add(jlt); 
jdct.add(jtft); 
} 
jdct.add(jb); 
if ("替换...".equals(comm)) { 
JButton jball = new JButton("替换全部"); 
jball.addActionListener(this); 
jdct.add(jball); 
} 
jdct.pack(); 
jdct.setResizable(false); 
jdct.setLocation(400, 240); 
jdct.setVisible(true); 
} 
if (comm.equals("全选")) { 
jta.selectAll(); 
} 
if (comm.equals("关于...")) { 
JDialog jdgy = new JDialog(jf, "关于我..."); 
 
 
jdgy.setLayout(new FlowLayout()); 
JLabel jl = new JLabel("制作者: xxx "); 
JLabel j2 = new JLabel("Email:xxxx@.com "); 
jdgy.add(jl); 
jdgy.add(j2); 
jdgy.setSize(180, 100); 
jdgy.setResizable(false); 
jdgy.setLocation(400, 240); 
jdgy.setVisible(true); 
} 
//查找实现 
if (comm.equals("查找")) { 
String str = jtf.getText(); 
String strall = jta.getText(); 
int n = strall.indexOf(str, set); 
if (n != -1) { 
set = n + 1; 
jta.setSelectionStart(n); 
jta.setSelectionEnd(n + str.length()); 
} 
} 
//替换实现 
if (comm.equals("替换") || comm.equals("替换全部")) { 
al.add(jta.getText()); 
String str = jtf.getText(); 
String strall = jta.getText(); 
if (comm.equals("替换全部")) { 
int n1 = 0; 
while (true) { 
set = strall.indexOf(str, n1); 
if (set == -1) 
break; 
n1 = set + 1; 
jta.setSelectionStart(set); 
jta.setSelectionEnd(set + str.length()); 
jta.replaceSelection(jtft.getText()); 
} 
set = 0; 
} 
int n = strall.indexOf(str, set); 
if (n == -1) { 
set = 0; 
} else { 
set = n + 1; 
jta.setSelectionStart(n); 
jta.setSelectionEnd(n + str.length()); 
jta.replaceSelection(jtft.getText()); 
} 
} 
} 
public Notepad() {//构造器 
jta.setLineWrap(true); 
jta.addMouseListener(this); 
JMenuBar jmb = new JMenuBar(); 
JMenu jm1 = new JMenu("文件"); 
String[] label1 = { "新建...", "打开...", "保存", "另存...", "退出" }; 
JMenuItem[] jmi1 = new JMenuItem[label1.length]; 
for (int i = 0; i < jmi1.length; i++) { 
jmi1[i] = new JMenuItem(label1[i]); 
jm1.add(jmi1[i]); 
jmi1[i].addActionListener(this); 
} 
jm1.insertSeparator(1); 
jm1.insertSeparator(3); 
jm1.insertSeparator(6); 
JMenu jm2 = new JMenu("编辑"); 
String[] label2 = { "撤销", "剪切", "复制", "粘贴", "删除", "查找...", "替换...", 
"全选" }; 
JMenuItem[] jmi2 = new JMenuItem[label2.length]; 
for (int i = 0; i < jmi2.length; i++) { 
jmi2[i] = new JMenuItem(label2[i]); 
jm2.add(jmi2[i]); 
jmi2[i].addActionListener(this); 
} 
jm2.insertSeparator(1); 
jm2.insertSeparator(5); 
jm2.insertSeparator(7); 
jm2.insertSeparator(10); 
JMenu jm3 = new JMenu("帮助"); 
JMenuItem jmi3 = new JMenuItem("关于..."); 
jm3.add(jmi3); 
jmi3.addActionListener(this); 
jmb.add(jm1); 
jmb.add(jm2); 
jmb.add(jm3); 
jf.setJMenuBar(jmb); 
jf.addWindowListener(new WindowAdapter() { 
public void windowClosing(WindowEvent e) { 
jf.removeAll(); 
jf.dispose(); 
} 
}); 
//鼠标右健弹出菜单 
JMenuItem jmi11, jmi22, jmi33, jmi44; 
pp.add(jmi11 = new JMenuItem("剪切")); 
pp.add(jmi22 = new JMenuItem("复制")); 
pp.add(jmi33 = new JMenuItem("粘贴")); 
pp.addSeparator(); 
pp.add(jmi44 = new JMenuItem("全选")); 
jmi11.addActionListener(this); 
jmi22.addActionListener(this); 
jmi33.addActionListener(this); 
jmi44.addActionListener(this); 
jf.add(pp); 
// 
//新建菜单 
jd.setLayout(new FlowLayout()); 
JButton jb1 = new JButton("是"); 
JButton jb2 = new JButton("否"); 
JButton jb3 = new JButton("取消"); 
jd.add(new JLabel("您当前编辑未保存,是否保存?")); 
jb1.addActionListener(this); 
jb2.addActionListener(this); 
jb3.addActionListener(this); 
jd.add(jb1); 
jd.add(jb2); 
jd.add(jb3); 
jd.pack(); 
jf.add(jsp); 
jf.pack(); 
jf.setLocation(300, 200); 
jf.setVisible(true); 
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
} 
public static void main(String[] args) { 
new Notepad(); 
} 
public void mouseClicked(MouseEvent e) { 
if (e.getButton() == 3) { 
pp.setVisible(true); 
pp.show(e.getComponent(), e.getX(), e.getY()); 
} 
} 
public void mouseEntered(MouseEvent e) { 
} 
public void mouseExited(MouseEvent e) { 
} 
public void mousePressed(MouseEvent e) { 
} 
public void mouseReleased(MouseEvent e) { 
} 
}