JAVA记事本的图形用户界面应用程序含过滤

JAVA记事本的图形用户界面应用程序 过滤

题目简介：

整体分析：

实验代码：

package note;

import java.awt.EventQueue;
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.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JFrame;
import java.awt.BorderLayout;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JSeparator;
import javax.swing.JTextArea;
import java.awt.Font;

/**记事本的图形用户界面应用程序 过滤
 * @author 李祖林
 *2017-6-23
 */
public class Note3 implements ActionListener{

    private JFrame frame;
    JMenuItem New,Open,Save,Close;
    JTextArea textArea;
    File fileName = new File("D://file.txt");

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Note3 window = new Note3();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public Note3() {

        frame = new JFrame();
        frame.setBounds(100, 100, 725, 392);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(new BorderLayout(0, 0));

        textArea = new JTextArea();
        textArea.setFont(new Font("华文中宋", Font.BOLD, 17));
        frame.getContentPane().add(textArea, BorderLayout.CENTER);

        JMenuBar menuBar = new JMenuBar();
        frame.setJMenuBar(menuBar);

        JMenu menu = new JMenu("\u6587\u4EF6");
        menuBar.add(menu);

        New = new JMenuItem("\u65B0\u5EFA");
        menu.add(New);New.addActionListener(this);

        Open = new JMenuItem("\u6253\u5F00");
        menu.add(Open);Open.addActionListener(this);

        Save = new JMenuItem("\u4FDD\u5B58");
        menu.add(Save);Save.addActionListener(this);

        JSeparator separator = new JSeparator();
        menu.add(separator);

        Close = new JMenuItem("\u9000\u51FA");
        menu.add(Close);Close.addActionListener(this);

        JMenu menu_1 = new JMenu("\u7F16\u8F91");
        menuBar.add(menu_1);

        JMenuItem menuItem_4 = new JMenuItem("\u590D\u5236");
        menu_1.add(menuItem_4);

        JMenuItem menuItem_5 = new JMenuItem("\u526A\u5207");
        menu_1.add(menuItem_5);

        JMenuItem menuItem_6 = new JMenuItem("\u7C98\u8D34");
        menu_1.add(menuItem_6);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == Close) {
            System.exit(0);
        } else if (e.getSource() == New) {
            textArea.setText("");
        } else if (e.getSource() == Save) {
            saveFile();
        } else if (e.getSource() == Open) {
            textArea.setText("");
            openFile();
        }

    }

    public void saveFile(){
        try {
            BufferedWriter bWriter = new BufferedWriter(new FileWriter(fileName));
                                                            //打开写入流
            String text = textArea.getText();                //获取文本框内容
            char[] ch = new char[1024];                        //字符串->>字符数组
            ch = text.toCharArray();
            int tmp;
            for(int i = 0;i < ch.length;i++){
                tmp = (int)ch[i];                            //字符->ASCII值
                if(tmp>='A'&&tmp<='Z'){                        //过滤
                    tmp += 32;
                }
                ch[i] = (char)tmp;                            //ASCII值->字符
            }
            text = String.valueOf(ch);                        //字符数组->>字符串
            bWriter.write(text);                            //写入
            bWriter.close();
        } catch (IOException e) {
            System.err.println("保存文件发生错误！");
            e.printStackTrace();                            //打印轨迹
        }
    }

    public void openFile(){
        try {
            BufferedReader bReader = new BufferedReader(new FileReader(fileName));
            String text;
            while((text = bReader.readLine())!=null){
                textArea.append(text+"\n");
            }
            bReader.close();
        } catch (IOException e) {
            System.err.println("打开文件发生错误！");
            e.printStackTrace();
        }
    }

}

实验结果：

过滤前：

过滤后：