第二次作业

一、实验目的

1.掌握软件开发的基本流程

2.掌握常用的软件开发方式和工具。

二、实验内容

1.设计一个包含登录界面的计算器软件，该软件可以实现第一次作业中的全部功能，同时可以保存用户的历史计算记录（保存数据最好使用数据库）。

三、程序流程图

1.注册流程图

2.登录流程图

四、代码实现

1.前端

(1)代码

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>登录</title>
<style>
body {
background-image: url('背景.jpg');
background-size: cover;
background-position: center;
font-family: Arial, sans-serif;
margin: 0;
padding: 0;
}

.container {
width: 350px;
margin: 100px auto;
background: rgba(255, 255, 255, 0.653);
padding: 20px;
border-radius: 20px;
text-align: center;
}

input[type="text"],
input[type="password"] {
width: 80%;
padding: 8px;
margin: 5px 0;
border-radius: 5px;
border: 1px solid #002aff;
}

input[type="submit"] {
width: 80%;
padding: 8px;
margin: 10px 0;
border-radius: 5px;
border: none;
background-color: #008cff;
color: white;
cursor: pointer;
}

.message {
margin-top: 10px;
}

.success {
color: rgb(0, 41, 128);
}

.error {
color: black;
font-weight: bold;
}
</style>
</head>
<body>
<div class="container">
<h2>登录</h2>
<form onsubmit="return validateForm()">
<input type="text" placeholder="用户名" id="username" required><br>
<input type="password" placeholder="密码" id="password" required><br>
<input type="submit" value="登录">
<div class="message" id="message"></div>
</form>
</div>

<script>
function validateForm() {
var username = document.getElementById('username').value;
var password = document.getElementById('password').value;
if (username === 'username' && password === 'password') {
document.getElementById('message').innerHTML = '<span class="success">登录成功!</span>';
window.location.href = 'http://localhost:D:\pace\counter\web\WEB-INF\web.xml';
return true;
} else {
document.getElementById('message').innerHTML = '<span class="error">用户名或者密码错误</span>';
return false;
}
}
</script>
</body>
</html>

（2）界面

2.后端

(1)代码

package Calculator;
import  javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileWriter;
import java.io.IOException;
public class Calculator extends JFrame {
    private JTextField inputField;
    private JTextField outputField;
    private String history = "";
    public Calculator(Object o) {
        setTitle("计算器");
        setSize(350, 450);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(null);
        getContentPane().setBackground(Color.WHITE);
        inputField = new JTextField();
        inputField.setBounds(10, 10, 280, 50);
        inputField.setBackground(Color.LIGHT_GRAY);
        inputField.setFont(new Font("Arial", Font.PLAIN, 20));
        add(inputField);
        outputField = new JTextField();
        outputField.setBounds(10, 70, 280, 50);
        outputField.setBackground(Color.LIGHT_GRAY);
        outputField.setFont(new Font("Arial", Font.PLAIN, 20));
        add(outputField);
        String[] buttons = {"7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", "C", "=", "+","."};
        int x = 10, y = 130;
        for (String buttonText : buttons) {
            JButton button = new JButton(buttonText);
            button.setBounds(x, y, 70, 50);
            button.setFont(new Font("Arial", Font.PLAIN, 20));
            button.addActionListener(new ButtonClickListener());
            add(button);
            x += 70;
            if (x > 220) {
                x = 10;
                y += 50;
            }
        }
        JButton sqrtButton = new JButton("√");
        sqrtButton.setBounds(80, 330, 70, 50);
        sqrtButton.setFont(new Font("Arial", Font.PLAIN, 20));
        sqrtButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    double num = Double.parseDouble(inputField.getText());
                    double result = calculateSqrt(num);
                    outputField.setText(String.valueOf(result));
                    saveHistory("√" + inputField.getText() + " = " + result + "\n");
                } catch (NumberFormatException ex) {
                    JOptionPane.showMessageDialog(null, "Invalid input", "Error", JOptionPane.ERROR_MESSAGE);
                }
            }
        });
        add(sqrtButton);
        JButton historyButton = new JButton("H");
        historyButton.setBounds(140, 330, 80, 50);
        historyButton.setFont(new Font("Arial", Font.PLAIN, 20));
        historyButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(null, history, "History", JOptionPane.INFORMATION_MESSAGE);
            }
        });
        add(historyButton);
    }
    public Calculator() {
    }
   private class ButtonClickListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            String command = e.getActionCommand();
            if (command.equals("C")) {
                inputField.setText("");
                outputField.setText("");
            } else if (command.equals("=")) {
                try {
                    double result = eval(inputField.getText());
                    outputField.setText(String.valueOf(result));
                    saveHistory(inputField.getText() + " = " + result + "\n");
                } catch (NumberFormatException ex) {
                    JOptionPane.showMessageDialog(null, "Invalid input", "Error", JOptionPane.ERROR_MESSAGE);
                }
            } else {
                inputField.setText(inputField.getText() + command);
            }
        }
    }
    private double eval(final String expression) {
        return new Object() {
            int pos = -1, ch;
            void nextChar() {
                ch = (++pos < expression.length()) ? expression.charAt(pos) : -1;
            }
            boolean eat(int charToEat) {
                while (ch == ' ') nextChar();
                if (ch == charToEat) {
                    nextChar();
                    return true;
                }
                return false;
            }
            double parse() {
                nextChar();
                double x = parseExpression();
                if (pos < expression.length()) throw new RuntimeException("Unexpected: " + (char) ch);
                return x;
            }
            double parseExpression() {
                double x = parseTerm();
                for (; ; ) {
                    if (eat('+')) x += parseTerm();
                    else if (eat('-')) x -= parseTerm();
                    else return x;
                }
            }
            double parseTerm() {
                double x = parseFactor();
                for (; ; ) {
                    if (eat('*')) x *= parseFactor();
                    else if (eat('/')) x /= parseFactor();
                    else return x;
                }
            }
            double parseFactor() {
                if (eat('+')) return parseFactor();
                if (eat('-')) return -parseFactor();
                double x;
                int startPos = this.pos;
                if (eat('(')) {
                    x = parseExpression();
                    eat(')');
                } else if ((ch >= '0' && ch <= '9') || ch == '.') {
                    while ((ch >= '0' && ch <= '9') || ch == '.') nextChar();
                    x = Double.parseDouble(expression.substring(startPos, this.pos));
                } else {
                    throw new RuntimeException("Unexpected: " + (char) ch);
                }
                if (eat('^')) x = Math.pow(x, parseFactor());
                return x;
            }
        }.parse();
    }
    private double calculateSqrt(double num) {
        if (num < 0) {
            throw new IllegalArgumentException("Cannot calculate square root of a negative number");
        }
        double x = num;
        while (true) {
            double y = (x + num / x) / 2;
            if (Math.abs(x - y) < 0.0000001) {
                break;
            }
            x = y;
        }
        return Math.round(x * 1000000.0) / 1000000.0;
    }
    private void saveHistory(String record) {
        history += record;
        try (FileWriter writer = new FileWriter("history.txt", true)) {
            writer.write(record);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        Calculator counter = new Calculator(null);
        counter.setVisible(true);
    }
}

(2)界面

3.数据库连接

import java.sql.Connection;

import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.*;
public class CalculatorHistory {
    // MySQL数据库连接参数
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String url = "jdbc:mysql://localhost:3306/history?characterEncoding=UTF-8";
    static final String user = "root";
    static final String password = "123456";

    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement stmt = null;
        try {
            // 注册 JDBC 驱动
            Class.forName(JDBC_DRIVER);

            // 打开一个连接
            System.out.println("连接数据库...");
            conn = DriverManager.getConnection(url, user, password);

            // 创建表（如果表不存在）
            String createTableSQL = "CREATE TABLE IF NOT EXISTS history (id INT AUTO_INCREMENT PRIMARY KEY, num1 DOUBLE, num2 DOUBLE, operator VARCHAR(1))";
            stmt = conn.prepareStatement(createTableSQL);
            stmt.executeUpdate();
            int id;
            VARCHAR operation=””;
            double result= 0.0;
            // 将计算历史记录插入到数据库中
            String insertSQL = "INSERT INTO history (operation,result) VALUES (?, ?)";
            stmt = conn.prepareStatement(insertSQL);
            stmt.setVarchar(1, operation);
            stmt.setDouble(2, result);
            stmt.executeUpdate();

            System.out.println("历史记录已成功保存到数据库。");

        } catch (SQLException se) {
            se.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (stmt != null) stmt.close();
            } catch (SQLException se2) {
            }
            try {
                if (conn != null) conn.close();
            } catch (SQLException se) {
                se.printStackTrace();
            }
        }
    }
}

4.数据库代码

CREATE TABLE users(
                                    id INT AUTO_INCREMENT PRIMARY KEY,
                                    user VARCHAR,
                                    password INT(16) NOT NULL,
                                    
);
SELECT * FROM users;
INSERT INTO users VALUES (1,'袁玲',1234567)；
INSERT INTO users VALUES (2,'袁二',7654321)；
INSERT INTO users VALUES (3,'袁三',1357910)；

posted @ 2023-12-05 00:37 llllly-343 阅读(40) 评论(0) 收藏举报

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第二次作业

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