Java Implementation Notepad Java Notepad source code and implementation __swing

Today to introduce you about how to implement Notepad in Java, is a very good case of learning Java Swing, the following first look at the results of the operation (download the address below):

Here we look at the source code:

[java]  View Plain  copy  import java.awt.*;    import java.awt.event.*;     import java.text.*;    import java.util.*;    import  java.io.*;    import javax.swing.undo.*;    import  javax.swing.border.*;    import javax.swing.*;    import  javax.swing.text.*;    import javax.swing.event.*;   import  java.awt.datatransfer.*;         public class notepad extends  jframe implements actionlistener,documentlistener   {   //Menu        JMenu fileMenu,editMenu,formatMenu,viewMenu,helpMenu;        //Right-click Popup        JPopupMenu popupMenu;        jmenuitem popupmenu_undo,popupmenu_cut,popupmenu_copy,popupmenu_paste,popupmenu_delete,popupmenu_selectall;       / /"File" menu items        jmenuitem filemenu_new,filemenu_open,filemenu_save,filemenu_ saveas,filemenu_pagesetup,filemenu_print,filemenu_exit;       //"Edit" menu item         jmenuitem editmenu_undo,editmenu_cut,editmenu_copy,editmenu_paste,editmenu_ Delete,editmenu_find,editmenu_findnext,editmenu_replace,editmenu_goto,editmenu_selectall,editmenu_timedate;        //"format" menu items        JCheckBoxMenuItem  formatmenu_linewrap;       JMenuItem formatMenu_Font;        //"View" menu items        JCheckBoxMenuItem viewMenu_Status;        //"Help" menu items        jmenuitem helpmenu_helptopics , helpmenu_aboutnotepad;       //"text" Edit area        JTextArea  editarea;       //status bar label        JLabel  statuslabel;       //system Clipboard        Toolkit  Toolkit=toolkit.getdefaulttoolkit ();       clipboard clipboard= Toolkit.getsystemclipboard ();       //Create the Undo Operation Manager (related to the undo operation)         protected undomanager undo=new undomanager ();        Protected undoableeditlistener undohandler=new undohandler ();        //Other variables        string oldvalue;//store the original contents of the edit area to compare the text for changes