1、首先在电脑中新建一个记事本，将记事本的后缀改为“.java”，如下图所示。
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2、然后使用记事本的方式打开，输入java程序代码，如下图所示。
3、接着在键盘上按“win+R”快捷键键打开运行，输入“cmd”，如下图所示。
4、在命令行输入“D:”，按“Enter”键进去D盘，再输入“cd Desktop”进去Desktop文件夹，如下图所示。
5、最后再输入“javac Test.java”，按“Enter”键编译java程序，如下图所示就完成了。
方法/步骤
下载JDK，并安装成功，CMD测试Java环境安装成功。出现如下提示则Java环境安装成功
打开mycelipse进入主界面，点击左上角file--new---java project,新建一个Java项目，项目名字任意取，这里我取名为note--然后点击完成，创建Java项目
然后右键项目下的src--new---package,新建一个包，包名我定为notetest，然后点击完成
然后右键我们建立好的包notetest--new--class，包名为Note,点击完成
首先我们想导入工程所需要的包，以便编写程序时进行调用
package notepad;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
首先定义好编写程序时变量，我们设为成员变量方便以后调用
public class Notepad{
//屏幕分辨率
int width = Toolkit.getDefaultToolkit().getScreenSize().width;
int height = Toolkit.getDefaultToolkit().getScreenSize().height;
//窗体
private Frame frm ;
//显示内容多行文本
private TextArea notetext;
//记事本菜单
private MenuBar mb;
//菜单
private Menu m ;
//菜单项
private MenuItem open,save;
为程序创建组件--Frame--菜单栏目--文本框TextArea
public Notepad(){init();}
private void init(){
frm = new Frame("模拟记事本");
//设置菜单
mb = new MenuBar();
m = new Menu("文件");
//显示文件的地方
notetext = new TextArea();
notetext.setBounds(30, 50, 750, 500);
frm.add(notetext);
myEvent();
为控件和按钮添加监听事件
private void myEvent() {
//打开菜单的事件处理
open.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//判断路径和文件名是否为空 如果为空结束程序
if(dir == null || name == null)
//如果不为空讲路径名和文件名封装到File对象里
file = new File(dir,name);
//使用字符缓冲读取文件
BufferedReader bfr = null;
try {
bfr = new BufferedReader(new FileReader(file));
});
save.addActionListener(new ActionListener(){
//获取路径和文件名
String dir =fd.getDirectory();
String name = fd.getFile();
//如果不为空讲路径名和文件名封装到File对象里
file = new File(dir,name);
}
BufferedWriter bfr= null;
}
});
}
}
然后创建主方法，开始测试程序，新建一个NoteDemo类
package notepad;
public class NoteDemo {
public static void main(String[] args) {
new Notepad();
}
}
importjava.awt.BorderLayout;importjava.awt.Container;importjava.awt.Font;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;importjava.awt.event.InputEvent;importjava.awt.event.KeyAdapter;importjava.awt.event.KeyEvent;importjava.awt.event.MouseAdapter;importjava.awt.event.MouseEvent;importjava.awt.event.WindowAdapter;importjava.awt.event.WindowEvent;importjava.io.BufferedReader;importjava.io.BufferedWriter;importjava.io.File;importjava.io.FileReader;importjava.io.FileWriter;importjava.io.IOException;importjavax.swing.BorderFactory;importjavax.swing.JFileChooser;importjavax.swing.JFrame;importjavax.swing.JLabel;importjavax.swing.JMenu;importjavax.swing.JMenuBar;importjavax.swing.JMenuItem;importjavax.swing.JOptionPane;importjavax.swing.JPopupMenu;importjavax.swing.JScrollPane;importjavax.swing.JTextArea;importjavax.swing.KeyStroke;importjavax.swing.ScrollPaneConstants;importjavax.swing.SwingConstants;publicclassJNotePadUIextendsJFrame{privateJMenuItemmenuOpen;privateJMenuItemmenuSave;privateJMenuItemmenuSaveAs;privateJMenuItemmenuClose;privateJMenueditMenu;privateJMenuItemmenuCut;privateJMenuItemmenuCopy;privateJMenuItemmenuPaste;privateJMenuItemmenuAbout;privateJTextAreatextArea;privateJLabelstateBar;privateJFileChooserfileChooser;privateJPopupMenupopUpMenu;publicJNotePadUI(){super("新建文本文件");setUpUIComponent();setUpEventListener();setVisible(true);}privatevoidsetUpUIComponent(){setSize(640,480);//菜单栏JMenuBarmenuBar=newJMenuBar();//设置「文件」菜单JMenufileMenu=newJMenu("文件");menuOpen=newJMenuItem("打开");//快捷键设置menuOpen.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,InputEvent.CTRL_MASK));menuSave=newJMenuItem("保存");menuSave.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,InputEvent.CTRL_MASK));menuSaveAs=newJMenuItem("另存为");menuClose=newJMenuItem("关闭");menuClose.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q,InputEvent.CTRL_MASK));fileMenu.add(menuOpen);fileMenu.addSeparator();//分隔线fileMenu.add(menuSave);fileMenu.add(menuSaveAs);fileMenu.addSeparator();//分隔线fileMenu.add(menuClose);//设置「编辑」菜单JMenueditMenu=newJMenu("编辑");menuCut=newJMenuItem("剪切");menuCut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,InputEvent.CTRL_MASK));menuCopy=newJMenuItem("复制");menuCopy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,InputEvent.CTRL_MASK));menuPaste=newJMenuItem("粘贴");menuPaste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V,InputEvent.CTRL_MASK));editMenu.add(menuCut);editMenu.add(menuCopy);editMenu.add(menuPaste);//设置「关于」菜单JMenuaboutMenu=newJMenu("关于");menuAbout=newJMenuItem("关于JNotePad");aboutMenu.add(menuAbout);menuBar.add(fileMenu);menuBar.add(editMenu);menuBar.add(aboutMenu);setJMenuBar(menuBar);//文字编辑区域textArea=newJTextArea();textArea.setFont(newFont("宋体",Font.PLAIN,16));textArea.setLineWrap(true);JScrollPanepanel=newJScrollPane(textArea,ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);ContainercontentPane=getContentPane();contentPane.add(panel,BorderLayout.CENTER);//状态栏stateBar=newJLabel("未修改");stateBar.setHorizontalAlignment(SwingConstants.LEFT);stateBar.setBorder(BorderFactory.createEtchedBorder());contentPane.add(stateBar,BorderLayout.SOUTH);popUpMenu=editMenu.getPopupMenu();fileChooser=newJFileChooser();}privatevoidsetUpEventListener(){//按下窗口关闭钮事件处理addWindowListener(newWindowAdapter(){publicvoidwindowClosing(WindowEvente){closeFile();}});//菜单-打开menuOpen.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){openFile();}});//菜单-保存menuSave.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){saveFile();}});//菜单-另存为menuSaveAs.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){saveFileAs();}});//菜单-关闭文件menuClose.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){closeFile();}});//菜单-剪切menuCut.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){cut();}});//菜单-复制menuCopy.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){copy();}});//菜单-粘贴menuPaste.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){paste();}});//菜单-关于menuAbout.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){//显示对话框JOptionPane.showOptionDialog(null,"程序名称:\nJNotePad\n"+"程序设计:\n\n"+"简介:\n一个简单的文字编辑器\n"+"可作为验收Java的实现对象\n"+"欢迎网友下载研究交流\n\n"+"/","关于JNotePad",JOptionPane.DEFAULT_OPTION,JOptionPane.INFORMATION_MESSAGE,null,null,null);}});//编辑区键盘事件textArea.addKeyListener(newKeyAdapter(){publicvoidkeyTyped(KeyEvente){processTextArea();}});//编辑区鼠标事件textArea.addMouseListener(newMouseAdapter(){publicvoidmouseReleased(MouseEvente){if(e.getButton()==MouseEvent.BUTTON3)popUpMenu.show(editMenu,e.getX(),e.getY());}publicvoidmouseClicked(MouseEvente){if(e.getButton()==MouseEvent.BUTTON1)popUpMenu.setVisible(false);}});}privatevoidopenFile(){if(isCurrentFileSaved()){//文件是否为保存状态open();//打开}else{//显示对话框intoption=JOptionPane.showConfirmDialog(null,"文件已修改，是否保存？","保存文件？",JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null);switch(option){//确认文件保存caseJOptionPane.YES_OPTION:saveFile();//保存文件break;//放弃文件保存caseJOptionPane.NO_OPTION:open();break;}}}privatebooleanisCurrentFileSaved(){if(stateBar.getText().equals("未修改")){returnfalse;}else{returntrue;}}privatevoidopen(){//fileChooser是JFileChooser的实例//显示文件选取的对话框intoption=fileChooser.showDialog(null,null);//使用者按下确认键if(option==JFileChooser.APPROVE_OPTION){try{//开启选取的文件BufferedReaderbuf=newBufferedReader(newFileReader(fileChooser.getSelectedFile()));//设定文件标题setTitle(fileChooser.getSelectedFile().toString());//清除前一次文件textArea.setText("");//设定状态栏stateBar.setText("未修改");//取得系统相依的换行字符StringlineSeparator=System.getProperty("line.separator");//读取文件并附加至文字编辑区Stringtext;while((text=buf.readLine())!=null){textArea.append(text);textArea.append(lineSeparator);}buf.close();}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"开启文件失败",JOptionPane.ERROR_MESSAGE);}}}privatevoidsaveFile(){//从标题栏取得文件名称Filefile=newFile(getTitle());//若指定的文件不存在if(!file.exists()){//执行另存为saveFileAs();}else{try{//开启指定的文件BufferedWriterbuf=newBufferedWriter(newFileWriter(file));//将文字编辑区的文字写入文件buf.write(textArea.getText());buf.close();//设定状态栏为未修改stateBar.setText("未修改");}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"写入文件失败",JOptionPane.ERROR_MESSAGE);}}}privatevoidsaveFileAs(){//显示文件对话框intoption=fileChooser.showSaveDialog(null);//如果确认选取文件if(option==JFileChooser.APPROVE_OPTION){//取得选择的文件Filefile=fileChooser.getSelectedFile();//在标题栏上设定文件名称setTitle(file.toString());try{//建立文件file.createNewFile();//进行文件保存saveFile();}catch(IOExceptione){JOptionPane.showMessageDialog(null,e.toString(),"无法建立新文件",JOptionPane.ERROR_MESSAGE);}}}privatevoidcloseFile(){//是否已保存文件if(isCurrentFileSaved()){//释放窗口资源，而后关闭程序dispose();}else{intoption=JOptionPane.showConfirmDialog(null,"文件已修改，是否保存？","保存文件？",JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE,null);switch(option){caseJOptionPane.YES_OPTION:saveFile();break;caseJOptionPane.NO_OPTION:dispose();}}}privatevoidcut(){textArea.cut();stateBar.setText("已修改");popUpMenu.setVisible(false);}privatevoidcopy(){textArea.copy();popUpMenu.setVisible(false);}privatevoidpaste(){textArea.paste();stateBar.setText("已修改");popUpMenu.setVisible(false);}privatevoidprocessTextArea(){stateBar.setText("已修改");}publicstaticvoidmain(String[]args){newJNotePadUI();}}
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.io.*;
import java.awt.datatransfer.*;public class NewEdit
{
public static void main(String args[])
{
MyFrame EditFrame=new MyFrame();
EditFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
EditFrame.setVisible(true);
}
}class MyFrame extends JFrame
{
public MyFrame()
{ Dimension screenSize=toolKit.getScreenSize();
int screenHeight=screenSize.height;
int screenWidth=screenSize.width;
setSize(screenWidth/2,screenHeight/2);
setLocation(screenWidth/4,screenHeight/4);
Image img=toolKit.getImage("icon.gif");
setIconImage(img);
setTitle("MyEdit");
JMenuBar menuBar=new JMenuBar();
setJMenuBar(menuBar);
JMenu fileMenu=new JMenu("文件");
JMenu editMenu=new JMenu("编辑");
JMenu helpMenu=new JMenu("帮助");
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(helpMenu);
JMenuItem newItem=new JMenuItem("新建");
newItem.addActionListener(new NewListener());
JMenuItem openItem=new JMenuItem("打开");
openItem.addActionListener(new OpenListener());
JMenuItem saveItem=new JMenuItem("保存");
saveItem.addActionListener(new SaveListener());
JMenuItem escItem=new JMenuItem("退出");
escItem.addActionListener(new
ActionListener()
{
public void actionPerformed(ActionEvent myE)
{
System.exit(0);
}
});
fileMenu.add(newItem);
fileMenu.add(openItem);
fileMenu.add(saveItem);
fileMenu.add(escItem);
JMenuItem allItem=new JMenuItem("全选");
//JMenuItem copyItem=new JMenuItem("复制");
//CopyAction copyAction=new CopyAction();
//copyItem.addActionListener(copyAction);
JMenuItem cutItem=new JMenuItem("剪切");
//JMenuItem pasteItem=new JMenuItem("粘贴");
//Action pasteAction=new PasteAction();
//pasteItem.addActionListener(pasteAction);
editMenu.add(allItem);
allItem.addActionListener(new
ActionListener()
{
public void actionPerformed(ActionEvent myE)
{
textArea.selectAll();
}
});
CopyAction copyAction=new CopyAction("剪切");
editMenu.add(copyAction);
CutAction cutAction=new CutAction("复制");
editMenu.add(cutAction);
Action pasteAction=new PasteAction("粘贴");
editMenu.add(pasteAction);
popup=new JPopupMenu();
popup.add(copyAction);
popup.add(pasteAction);
popup.add(cutAction);
textArea = new JTextArea();
textArea.add(popup);
textArea.addMouseListener(new
MouseListener(){
public void mouseClicked(MouseEvent e) {} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} public void mousePressed(MouseEvent e) {
if (e.getButton() == MouseEvent.BUTTON3)
{
popup.show(textArea, e.getX(), e.getY());
}
} public void mouseReleased(MouseEvent e) {} });//可尝试用MouseAdapter,代码可能更简单
JScrollPane scroller = new JScrollPane(textArea);
add(scroller);
//OR--this.getContentPane().add(scroller)
//scroller.setComponentPopupMenu(popup);
//textArea.setInheritsPopupMenu(true);
//scroller.addMouseListener(new MouseAdapter(){});
}
public void writeFile(String fileName)
{
try
{
File file = new File(fileName);
FileWriter write = new FileWriter(file);
write.write(textArea.getText());
write.close();
}
catch(Exception e){
System.out.println("Error closing file!");
}
}
public void openFile(String fileName)
{
try
{
File file = new File(fileName);
FileReader readIn = new FileReader(file);
int size = (int)file.length();
int charsRead = 0;
char[] content = new char[size];
while(readIn.ready())
charsRead += readIn.read(content,charsRead,size-charsRead);
readIn.close();
textArea.setText(new String(content,0,charsRead));
}
catch(IOException e)
{
System.out.println("Error opening file!");
}
}
private class NewListener implements ActionListener
{
public void actionPerformed(ActionEvent myE)
{
textArea.setText("");
}
}
private class OpenListener implements ActionListener
{
public void actionPerformed(ActionEvent myE)
{
openFileDialog.setVisible(true);
fileName = openFileDialog.getDirectory()+openFileDialog.getFile();
if(fileName != null)
{
openFile(fileName);
}
}
}
private class SaveListener implements ActionListener
{
public void actionPerformed(ActionEvent myE)
{
saveFileDialog.setVisible(true);
fileName = saveFileDialog.getDirectory()+saveFileDialog.getFile();
if(fileName !=null)
{
writeFile(fileName);
}
}
}
private class CutAction extends AbstractAction
{
public CutAction(String name)
{
super(name);
}
public void actionPerformed(ActionEvent event)
{
String text = textArea.getSelectedText();
StringSelection selection = new StringSelection(text);
clipboard.setContents(selection,null);
textArea.replaceRange("",textArea.getSelectionStart(),
textArea.getSelectionEnd());
}
}
private class CopyAction extends AbstractAction
{
public CopyAction(String name)
{
super(name);
}
public void actionPerformed(ActionEvent event)
{
String text = textArea.getSelectedText();
StringSelection selection= new StringSelection(text);
clipboard.setContents(selection,null);
}
}
private class PasteAction extends AbstractAction
{
public PasteAction(String name)
{
super(name);
}
public void actionPerformed(ActionEvent event)
{
Transferable contents = clipboard.getContents(this);
if(contents==null)
return;
String text;
text="";
try
{
text = (String)contents.getTransferData(DataFlavor.stringFlavor);
}
catch(Exception ex){}
textArea.replaceRange(text,
textArea.getSelectionStart(),textArea.getSelectionEnd());
}
}
private JTextArea textArea;
private JPopupMenu popup;
private String fileName="";
private FileDialog openFileDialog=new FileDialog(this,"OpenFile",FileDialog.LOAD); private FileDialog saveFileDialog=new FileDialog(this,"SaveFile",FileDialog.SAVE);
Toolkit toolKit = Toolkit.getDefaultToolkit();
private Clipboard clipboard = toolKit.getSystemClipboard();}
