如何手动JAVA开发

如何手动开发JAVA？背景

我们需要实现一个简单的学生成绩管理系统，可以记录学生的基本信息和成绩，并提供查询、添加、删除和修改学生信息的功能。为了实现这个系统，我们需要JAVA开发。

首先，为了存储学生的信息和成绩，我们需要设计数据库的结构。我们可以创建两个表：students和scores。students表格包含学生的基本信息，如学号、姓名、性别等；scores表格包含学生的成绩信息，如学号、科目、成绩等。两个表格可以通过学号关联。

CREATE TABLE students (    id INT AUTO_INCREMENT PRIMARY KEY,    student_id VARCHAR(20) NOT NULL,    name VARCHAR(50) NOT NULL,    gender VARCHAR(10) NOT NULL);CREATE TABLE scores (    id INT AUTO_INCREMENT PRIMARY KEY,    student_id VARCHAR(20) NOT NULL,    subject VARCHAR(50) NOT NULL,    score INT NOT NULL,    FOREIGN KEY (student_id) REFERENCES students(student_id));

接下来，我们可以编写学生信息管理类，提供学生信息的增加、删除、更改和检查功能。

public class StudentManager {    private Connection connection;    public StudentManager(Connection connection) {        this.connection = connection;    }    public void addStudent(Student student) {        try {            PreparedStatement statement = connection.prepareStatement(                "INSERT INTO students (student_id, name, gender) VALUES (?, ?, ?, ?)"            );            statement.setString(1, student.getStudentId());            statement.setString(2, student.getName());            statement.setString(3, student.getGender());            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public void deleteStudent(String studentId) {        try {            PreparedStatement statement = connection.prepareStatement(                "DELETE FROM students WHERE student_id = ?"            );            statement.setString(1, studentId);            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public void updateStudent(Student student) {        try {            PreparedStatement statement = connection.prepareStatement(                "UPDATE students SET name = ?, gender = ?, gender = ? WHERE student_id = ?"            );            statement.setString(1, student.getName());            statement.setString(2, student.getGender());            statement.setString(3, student.getStudentId());            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public Student getStudent(String studentId) {        try {            PreparedStatement statement = connection.prepareStatement(                "SELECT * FROM students WHERE student_id = ?"            );            statement.setString(1, studentId);            ResultSet resultSet = statement.executeQuery();            if (resultSet.next()) {                String name = resultSet.getString("name");                String gender = resultSet.getString("gender");                return new Student(studentId, name, gender);            }        } catch (SQLException e) {            e.printStackTrace();        }        return null;    }}

除学生信息管理外，我们还需要一个成绩管理类别来提供学生成绩的增加、删除、更改和检查功能。

public class ScoreManager {    private Connection connection;    public ScoreManager(Connection connection) {        this.connection = connection;    }    public void addScore(Score score) {        try {            PreparedStatement statement = connection.prepareStatement(                "INSERT INTO scores (student_id, subject, score) VALUES (?, ?, ?, ?)"            );            statement.setString(1, score.getStudentId());            statement.setString(2, score.getSubject());            statement.setInt(3, score.getScore());            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public void deleteScore(int scoreId) {        try {            PreparedStatement statement = connection.prepareStatement(                "DELETE FROM scores WHERE id = ?"            );            statement.setInt(1, scoreId);            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public void updateScore(Score score) {        try {            PreparedStatement statement = connection.prepareStatement(                "UPDATE scores SET subject = ?, score = ?, score = ? WHERE id = ?"            );            statement.setString(1, score.getSubject());            statement.setInt(2, score.getScore());            statement.setInt(3, score.getId());            statement.executeUpdate();        } catch (SQLException e) {            e.printStackTrace();        }    }    public List<Score> getScores(String studentId) {        List<Score> scores = new ArrayList<>();        try {            PreparedStatement statement = connection.prepareStatement(                "SELECT * FROM scores WHERE student_id = ?"            );            statement.setString(1, studentId);            ResultSet resultSet = statement.executeQuery();            while (resultSet.next()) {                int id