Java核心代码（六） 桌面程序--记事本

参考文档http://wenku.baidu.com/view/45450b0f79563c1ec4da7101.html

 

1、命令：

 

D:\desktop>javac -d ./ JNotePad.java

D:\desktop>jar cvf jnotepad.jar desktop

added manifest

adding: desktop/(in = 0) (out= 0)(stored 0%)

adding: desktop/11/(in = 0) (out= 0)(stored 0%)

adding: desktop/JNotePad$1.class(in = 520) (out= 342)(deflated 34%)

 

打开jnotepad.jar\META-INF\MAINIFEST.MF添加：

Main-Class: desktop.JNotePad

 

2、记事本代码：

 

package desktop;import java.awt.BorderLayout;import java.awt.Container;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.InputEvent;import java.awt.event.KeyAdapter;import java.awt.event.KeyEvent;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.JOptionPane;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.KeyStroke;import javax.swing.ScrollPaneConstants;/** * @author timeriver.wang * @date 2013-01-04 6:23:45 PM */public class JNotePad extends JFrame {    private JMenu fileMenu;//should be filed or local variables?    private JMenuItem openMenuItem;    private JMenuItem saveMenuItem;    private JMenuItem saveAsMenuItem;    private JMenuItem closeMenuItem;    private JMenuItem aboutMenuItem;    private JTextArea textArea;    private JFileChooser fileChooser;    private boolean isChanged = false;    public JNotePad() {        super( "new txt file" );        setUI();        setEventListener();        setVisible( true );    }    public static void main( String[] args ) {        new JNotePad();    }        private void setUI() {        setSize( 640, 480 );        JMenuBar menuBar = new JMenuBar();        //-------------------------------//        //file Menu        //-------------------------------//        fileMenu = new JMenu( "file" );        openMenuItem = new JMenuItem( "open" );        // shortcut key,VK_O-->'O',CTRL_MASK-->"ctrl"        openMenuItem.setAccelerator( KeyStroke.getKeyStroke( KeyEvent.VK_O, InputEvent.CTRL_MASK ) );        saveMenuItem = new JMenuItem( "save" );        saveMenuItem.setAccelerator( KeyStroke.getKeyStroke( KeyEvent.VK_S, InputEvent.CTRL_MASK ) );        saveAsMenuItem = new JMenuItem( "save as" );        closeMenuItem = new JMenuItem( "close" );        closeMenuItem.setAccelerator( KeyStroke.getKeyStroke( KeyEvent.VK_Q, InputEvent.CTRL_MASK ) );        fileMenu.add( openMenuItem );        fileMenu.addSeparator();         fileMenu.add( saveMenuItem );        fileMenu.addSeparator();        fileMenu.add( saveAsMenuItem );        fileMenu.addSeparator();         fileMenu.add( closeMenuItem );        //-------------------------------//        //help Menu        //-------------------------------//        JMenu helpMenu = new JMenu( "help" );        aboutMenuItem = new JMenuItem( "about" );        helpMenu.add( aboutMenuItem );        //        menuBar.add( fileMenu );        menuBar.add( helpMenu );        //        setJMenuBar( menuBar );        // textArea        textArea = new JTextArea();        textArea.setLineWrap( true );        JScrollPane panel = new JScrollPane( textArea,             ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,            ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED );        Container contentPane = getContentPane();        contentPane.add( panel, BorderLayout.CENTER );        //         fileChooser = new JFileChooser();    }    private void setEventListener() {        addWindowListener( new WindowAdapter() {            public void windowClosing( WindowEvent e ) {                closeFile();            }        } );        openMenuItem.addActionListener( new ActionListener() {            public void actionPerformed( ActionEvent e ) {                openFile();            }        } );        saveMenuItem.addActionListener( new ActionListener() {            public void actionPerformed( ActionEvent e ) {                saveFile();            }        } );        saveAsMenuItem.addActionListener( new ActionListener() {            public void actionPerformed( ActionEvent e ) {                saveFileAs();            }        } );        closeMenuItem.addActionListener( new ActionListener() {            public void actionPerformed( ActionEvent e ) {                closeFile();            }        } );        aboutMenuItem.addActionListener( new ActionListener() {            public void actionPerformed( ActionEvent e ) {                JOptionPane.showOptionDialog( null,                     "java desktop demo,jar,started by bat command", "about JNotePad",                    JOptionPane.DEFAULT_OPTION, JOptionPane.INFORMATION_MESSAGE, null, null,                    null );            }        } );        // key event        textArea.addKeyListener( new KeyAdapter() {            public void keyTyped( KeyEvent e ) {            }        } );        // mouse event        textArea.addMouseListener( new MouseAdapter() {            public void mouseReleased( MouseEvent e ) {            }            public void mouseClicked( MouseEvent e ) {            }        } );    }    private void openFile() {        if ( !isChanged ) {            open();        }else {            int option = JOptionPane.showConfirmDialog( null,                 "file is changed, do you want to save?", "save file?", JOptionPane.YES_NO_OPTION,                JOptionPane.WARNING_MESSAGE, null );            if(option == JOptionPane.YES_OPTION){                saveFile();             }else{                open();            }        }    }    private void open() {        int option = fileChooser.showDialog( null, null );        if ( option == JFileChooser.APPROVE_OPTION ) {            try {                BufferedReader buf = new BufferedReader( new FileReader( fileChooser.getSelectedFile() ) );                setTitle( fileChooser.getSelectedFile().toString() );                textArea.setText( "" );                isChanged = true;                String lineSeparator = System.getProperty( "line.separator" );                String text;                while ( ( text = buf.readLine() ) != null ) {                    textArea.append( text );                    textArea.append( lineSeparator );                }                buf.close();            }            catch ( IOException e ) {                JOptionPane.showMessageDialog( null, e.toString(),                     "open file fail!", JOptionPane.ERROR_MESSAGE );            }        }    }    private void saveFile() {        File file = new File( getTitle() );        if ( !file.exists() ) {            saveFileAs();        }else {            try {                BufferedWriter buf = new BufferedWriter( new FileWriter( file ) );                buf.write( textArea.getText() );                buf.close();                isChanged = false;            }            catch ( IOException e ) {                JOptionPane.showMessageDialog( null, e.toString(),                     "write file fail!", JOptionPane.ERROR_MESSAGE );            }        }    }    private void saveFileAs() {        int option = fileChooser.showSaveDialog( null );        if ( option == JFileChooser.APPROVE_OPTION ) {            File file = fileChooser.getSelectedFile();            setTitle( file.toString() );            try {                file.createNewFile();                saveFile();            }            catch ( IOException e ) {                JOptionPane.showMessageDialog( null, e.toString(),                     "save as file fail!", JOptionPane.ERROR_MESSAGE );            }        }    }    private void closeFile() {        if ( isChanged ) {            dispose();        }else {            int option = JOptionPane.showConfirmDialog( null,                 "file has changed,save?", "save file?", JOptionPane.YES_NO_OPTION,                JOptionPane.WARNING_MESSAGE, null );            if(option == JOptionPane.YES_OPTION){                saveFile();            }else{                dispose();            }        }    }}