mytexteditor.java

java的记事本

{ 
jb.addActionListener(new ActionListener() 
{ 
public void actionPerformed(ActionEvent e) 
{ 
doSaveAs(); 
} 
}); 
} 
else if(actionCommand.equals(quick[4])) 
{ 
jb.addActionListener(new ActionListener() 
{ 
public void actionPerformed(ActionEvent e) 
{ 
jta.copy(); 
} 
}); 
} 
else if(actionCommand.equals(quick[5])) 
{ 
jb.addActionListener(new ActionListener() 
{ 
public void actionPerformed(ActionEvent e) 
{ 
jta.paste(); 
} 
}); 
} 
else 
{ 
jb.addActionListener(new ActionListener() 
{ 
public void actionPerformed(ActionEvent e) 
{ 
jta.cut(); 
} 
}); 
} 
} 
public ImageIcon createImage(String str) 
{ 
java.net.URL url=MyTextEditor.class.getResource(str); 
if(url==null) return null; 
else 
return new ImageIcon(url); 
} 
public static void main(String args[]) 
{ 
new MyTextEditor().show(); //技巧。 
} 
public void newactionlistener() 
{ 
if(changed==true) 
{ 
int n; 
Object option[]={"YES","NO","CANCEL"}; 
n=JOptionPane.showOptionDialog(null, 
"你的文件还没有保存呢，你想现在保存吗？", 
"保存", 
JOptionPane.YES_NO_CANCEL_OPTION, 
JOptionPane.QUESTION_MESSAGE, 
null, 
option, 
option[0]); 
switch(n) 
{ 
case JOptionPane.YES_OPTION: 
doSave(fileName); //保存文件 
fileName=""; //清空文件名 
jta.setText(""); //清空编辑区 
changed=false; //新建文件后，把更新标志改为false; 
break; 
case JOptionPane.NO_OPTION: 
fileName=""; 
jta.setText(""); 
changed=false; 
break; 
case JOptionPane.CANCEL_OPTION: 
break; 
default: 
break; 
} 
} 
else 
{ 
fileName=""; 
jta.setText(""); 
} 
} 
public void openactionlistener() 
{ 
FileDialog fd=new FileDialog(MyTextEditor.this,"Open...",FileDialog.LOAD); //这里注意对象的名字 
fd.show(); 
if(fd.getFile()==null) //如果没有选择文件，则返回 
return; 
fileName=fd.getDirectory()+File.separator+fd.getFile();//取得文件名[包括路径] 
FileInputStream fis=null; //好习惯，在定义的时候先初始化。 
String str1=null; 
try 
{ 
fis=new FileInputStream(fileName); 
int size=fis.available(); 
byte bytes[]=new byte[size]; 
fis.read(bytes); // 读取文件 
str1=new String(bytes); //建立字符串数组 
}catch(IOException e1) 
{} 
finally 
{ 
try 
{ 
fis.close(); 
}catch(IOException e2){} 
} 
if(str1!=null){jta.setText(str1);} 
changed=false; 
} 
class A implements ActionListener 
{ 
public void actionPerformed(ActionEvent e) 
{ 
Object o=e.getSource(); 
JMenuItem jmi=(JMenuItem)o; 
if(jmi==newjmi) 
{ 
newactionlistener(); 
} 
else if(jmi==openjmi) 
{ 
openactionlistener(); 
} 
else if(jmi==savejmi) 
{ 
doSave(fileName); 
} 
else if(jmi==saveasjmi) 
{ 
doSaveAs(); 
} 
else if(jmi==exitjmi) 
{ 
if(changed==true) 
{ 
int n; 
Object[] option={"YES","NO"}; 
n=JOptionPane.showOptionDialog(null, 
"你的文件还没有保存呢，你想现在保存吗？", 
"保存", 
JOptionPane.YES_NO_OPTION, 
JOptionPane.QUESTION_MESSAGE, 
null, 
option, 
option[0]); 
switch(n) 
{ 
case JOptionPane.YES_OPTION: 
doSave(fileName); 
break; 
case JOptionPane.NO_OPTION: 
break; 
default: break; 
} 
} 
System.exit(0); 
} 
else if(jmi==copyjmi) 
{ 
jta.copy(); 
} 
else if(jmi==pastejmi) 
{ 
jta.paste(); 
} 
else if(jmi==cutjmi) 
{ 
jta.cut(); 
} 
else if(jmi==findjmi) 
{ 
new Finder(MyTextEditor.this,jta).show(); 
} 
else if(jmi==fjmi) 
{ 
Color newColor=JColorChooser.showDialog(MyTextEditor.this,"选择字体颜色",jta.getForeground()); 
if(newColor!=null) jta.setForeground(newColor); 
} 
else if(jmi==bjmi) 
{ 
Color newColor=JColorChooser.showDialog(MyTextEditor.this,"选择字体颜色",jta.getBackground()); 
if(newColor!=null) jta.setBackground(newColor); 
} 
else if(jmi==aboutjmi) 
{ 
new About(MyTextEditor.this,true); 
} 
else; 
} 
} 
public void doSave(String fileName) 
{ 
if(fileName=="") 
{ 
doSaveAs(); 
return; 
} 
FileOutputStream fos=null; 
String str3=jta.getText(); 
try 
{ 
fos=new FileOutputStream(fileName); 
fos.write(str3.getBytes()); 
}catch(IOException e1){} 
finally 
{ 
try 
{fos.close();}catch(IOException e2){} 
} 
changed=false; 
} 
public void doSaveAs() 
{ 
FileDialog fd=new FileDialog(MyTextEditor.this,"Save...",FileDialog.SAVE); 
fd.show(); 
if(fd.getFile()==null) return; 
fileName=fd.getDirectory()+File.separator+fd.getFile(); 
String str4=jta.getText(); 
FileOutputStream fos=null; 
try 
{ 
fos=new FileOutputStream(fileName); 
fos.write(str4.getBytes()); 
}catch(IOException e1){} 
finally 
{ 
try{fos.close();}catch(IOException e2){} 
} 
changed=false; 
} 
} 

class Finder extends JDialog implements ActionListener 
{ 
JFrame jf; 
JTextArea jta; 
JButton findButton,closeButton; 
JPanel findPane,buttonPane; 
JLabel findLabel; 
JTextField jtf; 
public Finder(JFrame jf,JTextArea jta) 
{ 
super(jf,true); //JDialog的构造方法。必须是第一句。 
super.setTitle("查找"); 
super.getContentPane().setLayout(new GridBagLayout()); 
this.jf=jf; 
this.jta=jta; 
initComponents(); 
this.setLocationRelativeTo(jf); 
this.pack(); 
this.requestFocus(); 
this.addWindowListener(new WindowAdapter() 
{ 
public void windowClosing(WindowEvent e) 
{ 
Finder.this.dispose(); 
} 
}); 
} 
public void initComponents() 
{ 
GridBagConstraints gbc=new GridBagConstraints();//GridBagLayout要和GridBagConstraints一起用才有效果。 
gbc.fill=GridBagConstraints.HORIZONTAL; 
gbc.weightx=1.0; 
gbc.insets=new Insets(0,5,0,0); 

findButton=new JButton(); 
closeButton=new JButton(); 
findPane=new JPanel(); 
buttonPane=new JPanel(); 
findLabel=new JLabel(); 
jtf=new JTextField(); 
findPane.setLayout(new GridBagLayout()); 
findLabel.setText("查找内容"); 
findLabel.setLabelFor(jtf); 
findPane.add(findLabel,new GridBagConstraints()); 
jtf.addActionListener(this); //在文本框里面按回车键。 
findPane.add(jtf,gbc); 
gbc=new GridBagConstraints(); 
gbc.fill=GridBagConstraints.BOTH; 
gbc.insets=new Insets(11,12,0,11); 
this.getContentPane().add(findPane,gbc); 
buttonPane.setLayout(new GridBagLayout()); 
findButton.setText("查找"); 
findButton.setMnemonic(KeyEvent.VK_F); 
findButton.setToolTipText("查找"); 
findButton.addActionListener(this); 
buttonPane.add(findButton,new GridBagConstraints()); 
closeButton.setText("关闭"); 
closeButton.setMnemonic(KeyEvent.VK_C); 
closeButton.setToolTipText("关闭"); 
closeButton.addActionListener(this); 
gbc=new GridBagConstraints(); 
gbc.insets=new Insets(0,5,0,0); 
buttonPane.add(closeButton,gbc); 
gbc=new GridBagConstraints(); 
gbc.gridx=0;gbc.gridy=1; 
gbc.anchor=GridBagConstraints.SOUTHEAST; 
gbc.insets=new Insets(17,12,11,11); 
this.getContentPane().add(buttonPane,gbc); 
} 
public void actionPerformed(ActionEvent e) 
{ 
String textStr=jta.getText(); 
String findStr=jtf.getText(); 
if(findStr.equals("")); 
else 
{ 
int index=textStr.indexOf(findStr); 
if(index!=-1)//找到查找的内容 
{ 
jta.setCaretPosition(index); //将光标移到第index个字符上。 
} 
else 
Toolkit.getDefaultToolkit().beep(); 
} 
this.dispose(); //不管是按回车， 还是查找后，还是关闭，最后都要关闭。 
} 
} 

class About extends JDialog 
{ 
JFrame jf; 
JTextField jtf; 
public About(JFrame jf,boolean b) 
{ 
super(jf,b); 
this.jf=jf; 
initComponents(); 
this.getContentPane().add(jtf,BorderLayout.CENTER); 
super.setLocationRelativeTo(jf); 
super.pack(); 
this.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){About.this.dispose();}}); 
super.show(); 
} 
public void initComponents() 
{ 
jtf=new JTextField(); 
jtf.setBackground(new Color(0x44ffee)); 
jtf.setEditable(false); 
jtf.setText("一个简单的记事本"); 
} 
}