fileapp.java

java练习程序

import java.awt.*;
import java.io.*;
import java.awt.event.*;

public class FileAPP {
    public static void main(String args[]) {
        Frame_FileDialog f = new Frame_FileDialog();
    }
}


class Frame_FileDialog extends Frame implements ActionListener {
    FileDialog filedialog_save, filedialog_load; //声明2个文件对话框
    MenuBar menubar;
    Menu menu;
    MenuItem iteml, item2;
    TextArea text;
    BufferedReader in;
    FileReader File_Reader;
    BufferedWriter out;
    FileWriter tofile;
    Frame_FileDialog() {
        super("带文件对话框的窗口");
        setSize(60, 70);
        setVisible(true);
        menubar = new MenuBar();
        menu = new Menu("文件");
        iteml = new MenuItem("打开文件");
        item2 = new MenuItem("保存文件");
        iteml.addActionListener(this);
        item2.addActionListener(this);
        menu.add(iteml);
        menu.add(item2);
        menubar.add(menu);
        setMenuBar(menubar);
        filedialog_save = new FileDialog(this, "保存文件话框", FileDialog.SAVE);
        filedialog_save.setVisible(false);
        //再创建1-个依赖于该窗口的打开文件对话框
        filedialog_load = new FileDialog(this, "打开文件话框", FileDialog.LOAD);
        filedialog_load.setVisible(false);
        filedialog_save.addWindowListener(new WindowAdapter() { //对话框增力口适配器
            public void windowClosing(WindowEvent e) {
                filedialog_save.setVisible(false);
            }
        });
        filedialog_load.addWindowListener(new WindowAdapter() { //对话框增加适配器
            public void windowClosing(WindowEvent e) {
                filedialog_load.setVisible(false);
            }
        });
        addWindowListener(new WindowAdapter() { //窗口增加适配器
            public void windowClosing(WindowEvent e) {
                setVisible(false);
                System.exit(0);
            }
        });
        text = new TextArea(10, 10);
        text.setBackground(Color.cyan);
        add(text, "Center");
    }

    public void actionPerformed(ActionEvent e) { //实现接口冲的方法
        if (e.getSource() == iteml) {
            filedialog_load.setVisible(true);
            String s;
            try {
                //建立到文件file的FileReader流，该文件通过FPile类和对话框宋确定
                File file = new File(filedialog_load.getDirectory(),
                                     filedialog_load.getFile());
                File_Reader = new FileReader(file);
                in = new BufferedReader(File_Reader);
                while ((s = in.readLine()) != null) {
                    text.append(s + '\n');
                }
            } catch (FileNotFoundException el) {} catch (IOException e2) {}
            try {
                in.close();
                File_Reader.close();
            } catch (IOException exp) {}
        } else if (e.getSource() == item2) {
            filedialog_save.setVisible(true);
            try {
                //建立到文件file的FileWtiter流，该文件通过File类和对话框来确定
                File file = new File(filedialog_save.getDirectory(),
                                     filedialog_save.getFile());
                tofile = new FileWriter(file);
                out = new BufferedWriter(tofile);
                out.write(text.getText(), 0, (text.getText()).length());
                out.flush();
            } catch (FileNotFoundException e1) {} catch (IOException e2) {}
            try {
                out.close();
                tofile.close();
            } catch (IOException exp) {}
        }
    }
}