用JAVA语言写出1.生成一个简单文本编辑器,将生成的文本存入文件,如果有打开、存盘、关闭等菜单更佳。GUI界面可以自己灵活设计,同时实现窗体关闭退出功能。 2.编程实现一个加减法计算器。可以使用鼠标来完成加减法

1. 生成一个简单文本编辑器

代码如下：

import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;

public class TextEditor extends JFrame implements ActionListener {

    private JTextArea textArea;
    private JMenuBar menuBar;
    private JMenu fileMenu;
    private JMenuItem openMenuItem, saveMenuItem, closeMenuItem;

    public TextEditor() {
        super("Text Editor");
        initUI();
    }

    private void initUI() {
        // 创建文本区域
        textArea = new JTextArea();

        // 创建菜单栏
        menuBar = new JMenuBar();
        fileMenu = new JMenu("文件");

        // 创建菜单项
        openMenuItem = new JMenuItem("打开");
        saveMenuItem = new JMenuItem("保存");
        closeMenuItem = new JMenuItem("关闭");

        // 注册事件监听器
        openMenuItem.addActionListener(this);
        saveMenuItem.addActionListener(this);
        closeMenuItem.addActionListener(this);

        // 将菜单项添加到菜单上
        fileMenu.add(openMenuItem);
        fileMenu.add(saveMenuItem);
        fileMenu.add(closeMenuItem);

        // 将菜单添加到菜单栏上
        menuBar.add(fileMenu);

        // 设置窗口的菜单栏
        setJMenuBar(menuBar);

        // 将文本区域添加到窗口上
        add(new JScrollPane(textArea));

        // 设置窗口大小和关闭方式
        setSize(600, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        Object source = e.getSource();
        if (source == openMenuItem) {
            // 打开文件
            openFile();
        } else if (source == saveMenuItem) {
            // 保存文件
            saveFile();
        } else if (source == closeMenuItem) {
            // 关闭窗口
            dispose();
        }
    }

    private void openFile() {
        JFileChooser fileChooser = new JFileChooser();
        FileNameExtensionFilter filter = new FileNameExtensionFilter("文本文件", "txt");
        fileChooser.setFileFilter(filter);
        int result = fileChooser.showOpenDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            try {
                BufferedReader reader = new BufferedReader(new FileReader(file));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    sb.append(line);
                    sb.append(System.lineSeparator());
                }
                reader.close();
                textArea.setText(sb.toString());
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }

    private void saveFile() {
        JFileChooser fileChooser = new JFileChooser();
        FileNameExtensionFilter filter = new FileNameExtensionFilter("文本文件", "txt");
        fileChooser.setFileFilter(filter);
        int result = fileChooser.showSaveDialog(this);
        if (result == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            try {
                BufferedWriter writer = new BufferedWriter(new FileWriter(file));
                writer.write(textArea.getText());
                writer.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }

    public static void main(String[] args) {
        TextEditor editor = new TextEditor();
        editor.setVisible(true);
    }
}

2. 编程实现一个加减法计算器

代码如下：

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Calculator extends JFrame implements ActionListener {

    private JTextField inputField;
    private JButton addButton, subButton;
    private int result = 0;

    public Calculator() {
        super("Calculator");
        initUI();
    }

    private void initUI() {
        // 创建文本框和按钮
        inputField = new JTextField(10);
        addButton = new JButton("+");
        subButton = new JButton("-");

        // 注册事件监听器
        addButton.addActionListener(this);
        subButton.addActionListener(this);

        // 创建面板，并将组件添加到面板上
        JPanel panel = new JPanel();
        panel.add(inputField);
        panel.add(addButton);
        panel.add(subButton);

        // 将面板添加到窗口上
        add(panel);

        // 设置窗口大小和关闭方式
        setSize(300, 100);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        Object source = e.getSource();
        String inputStr = inputField.getText();
        if (inputStr.isEmpty()) {
            return;
        }
        int inputNum = Integer.parseInt(inputStr);
        if (source == addButton) {
            result += inputNum;
        } else if (source == subButton) {
            result -= inputNum;
        }
        inputField.setText("");
        JOptionPane.showMessageDialog(this, "结果为：" + result);
    }

    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        calculator.setVisible(true);
    }
}