notepad.java

一个实现记事本功能的小程序代码

package visual;

import java.awt.BorderLayout;
import java.awt.FileDialog;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

import javax.swing.JButton;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JToolBar;

public class NotePad extends JFrame {

	/**
	 * Launch the application
	 * @param args
	 */
	public static void main(String args[]) {
		try {
			NotePad frame = new NotePad();
			frame.setVisible(true);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * Create the frame
	 */
	private String file;
	private String temp;
	JPanel panel;
	JToolBar toolBar;
	JButton button;
	JLabel label;
	JButton button_1;
	JMenuBar menuBar;
	JMenu menu;
	JMenuItem menuItem;
	JMenuItem menuItem_1;
	JMenuItem menuItem_2;
	JScrollPane scrollPane;
	JEditorPane editorPane;
	JLabel label_1;
	JButton button_2;
	private StringBuffer reader=new StringBuffer();
	public NotePad() {
		super();
		setBounds(100, 100, 500, 494);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		panel = new JPanel();
		panel.setLayout(new BorderLayout());
		getContentPane().add(panel, BorderLayout.NORTH);

		toolBar = new JToolBar();
		panel.add(toolBar);

		button = new JButton();
		toolBar.add(button);
		button.setText("   打开   ");
		button.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				buttonActionPerformed();
			}
		});

		label = new JLabel();
		label.setText("             ");
		toolBar.add(label);

	    button_1 = new JButton();
		toolBar.add(button_1);
		button_1.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				button_1Performed();
			}
		});
		button_1.setText("   保存   ");

		label_1 = new JLabel();
		label_1.setText("             ");
		toolBar.add(label_1);

		button_2 = new JButton();
		button_2.setText("   退出   ");
		button_2.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				System.exit(0);
			}
		});
		toolBar.add(button_2);
		
		menuBar = new JMenuBar();
		setJMenuBar(menuBar);

		menu = new JMenu();
		menu.setText("文件");
		menuBar.add(menu);

		menuItem = new JMenuItem();
		menuItem.setText("打开");
		menuItem.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				buttonActionPerformed();
			}
		});
		menu.add(menuItem);
		
		menu.addSeparator();

		menuItem_1 = new JMenuItem();
		menuItem_1.setText("保存");
		menuItem_1.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				button_1Performed();
			}
		});
		menu.add(menuItem_1);

		menu.addSeparator();

	    JMenuItem menuItem_2 = new JMenuItem();
		menuItem_2.setText("退出");
		menuItem_2.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				System.exit(0);
			}
		});
		menu.add(menuItem_2);

		scrollPane = new JScrollPane();
		getContentPane().add(scrollPane);

		editorPane = new JEditorPane();
		scrollPane.setViewportView(editorPane);
		//
	}
	void buttonActionPerformed(){
		FileDialog filedialog=new FileDialog(this,"附件");
		filedialog.setVisible(true);
		file=filedialog.getDirectory()+filedialog.getFile();
		File f=new File(file);
		try {
			FileInputStream fis=new FileInputStream(f);
			InputStreamReader isr=new InputStreamReader(fis);
			BufferedReader br=new BufferedReader(isr);
			while((temp=br.readLine())!=null){
				reader.append(temp);
				reader.append("\n");
			}
			//System.out.println(reader);
			br.close();
			editorPane.setText(reader.toString());
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		};
	}
	void button_1Performed(){
		FileDialog filedialog=new FileDialog(this,"附件");
		filedialog.setVisible(true);
		file=filedialog.getDirectory()+filedialog.getFile();
		File f=new File(file);
		try {
			f.createNewFile();
			FileOutputStream fos=new FileOutputStream(f);
			OutputStreamWriter osw=new OutputStreamWriter(fos);
			BufferedWriter bw=new BufferedWriter(osw);
			temp=editorPane.getText();
			bw.write(temp);
			bw.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}